Glossary

If you have a term for the glossary, send it to me!

adventure riding—See “free-ride.”

aerobic—Activity that increases heart rate and breathing for an extended period of time, without putting breathing and heart rate at the maximum level (see “anaerobic”). Aerobic exercise practiced on a regular basis increases the heart’s ability to carry oxygenated blood to working muscles.

AheadSet—Also known by its generic name, “threadless headset”, it is a newer style headset component (see “headset”) that uses no threads to secure it to the fork steerer (see “fork steerer”). Instead, it uses a pre-load cap to set the down-force and a threadless stem (see “threadless stem”) that clamps to the fork’s steerer to hold the stem in place and keep the headset tight. It is lighter overall than a threaded headset/quill stem system and creates a more solid connection between the stem and steerer.

air spring—In a shock absorber, air is used as the spring medium. It is lighter than coil springs.

Alcoa CU92—Aluminum alloy (Al-Mg-Si) developed by Alcoa Aluminum, registered by the Aluminum Association as 6013 aluminum alloy.

alignment—When viewing a bicycle frameset linearly and vertically, the amount the frameset may differ in distance from the plane running through the center lines of the seat tube and head tube and still be acceptable as straight. May be expressed in either thousandths of an inch or micro-millimeters.

alloy—A mixture of different metals to produce a new metal with specifically improved characteristics, such as increased tensile strength, greater resistance to corrosion, etc. There is a primary material (i.e. steel, aluminum, or titanium) which is then mixed with smaller amounts of other materials such as vanadium, manganese, chromium, nickel, boron carbide, etc.

aluminum—Used in either bicycle frame tubing or parts, it is low density metal that is virtually always alloyed with other materials (see “alloy”) for bicycle use. It is light weight, durable, and has a high strength-to-weight ratio. When used in frame tubing, the tubes are typically oversized in diameter with thinner wall thicknesses to create acceptable lateral stiffness and light weight. It can also be formed in sheets to create a monocoque frame (see “monocoque”). When used in bicycle parts, it is either machined or forged (see “machined”, “forged”). It is lighter than steel, but actually not as strong as steel due to its modulus of elasticity rating (see “modulus of elasticity”).

amped—Pumped up, ready to go.

anaerobic—When heart and breathing rates reach maximum levels, with the consequent physical exertion causing lactic acid levels produced by the muscles to rise dramatically in proportion to the workload; as in, “I just went anaerobic.” Muscular activity occurring at such an intense rate delivers fuel without the utilization of oxygen. Cannot/should not be sustained for more than a few seconds. Reduction of exertion level is needed to decrease the burning sensation in the legs from lactic acid build-up (See “burn,” “blowing up”, “maximum heart rate”).

anaerobic exercise—(see “interval training”), specific training technique that increases strength and recovery of the heart by pushing it to its maximum heart rate (MHR) repeatedly (usually approximately 30 second intervals), followed by a controlled recovery period after each MHR period (usually getting the heart back down to around 120 beats per minutes for approximately 2-3 minutes).

animal—Very aggressive rider; powerful hill climber.

ankling—The action of pulling up with your legs on the upstroke of the pedal revolution.

ANSI (American National Standards Institute)—One of three recognized testing facilities that certifies bicycle helmets. ANSI’s testing protocol requires that a helmet fitted with a 13 pound head form be dropped onto both a hard flat surface and round surface. The helmet must not register more than 300 Gs to pass the test.

anodized—An electrolytic plating process that colors or hardens a very thin layer of the top surface of aluminum tubing or parts.

auger—To travel in a direct path toward the ground at a high rate of speed, displacing quite a bit of dirt with body and/or bike.

ATB—All Terrain Bike, a generic term for the mountain bike, but can also be used to describe a “city bike” or “trail bike.”

azimuth—a bearing taken relative to magnetic north for purposes of navigation.

Ball Burnished—A process by which small ceramic and/or metal balls are circulated at high speed over a surface to give it a polished appearance. This process also “cold works” the material’s outer layer, making the finished product even stronger and more resistant to failure.

bar-end—Also known as a climbing extension, these bolt-on handles provide additional hand positions as well as a more ergonomic hand position for climbing hills while raising up out of the saddle (see “honking”, “hammering”).

bail out—To cut short your ride; to terminate the desired direction of travel prior to completion of a turn, jump, climb, etc.; purposefully disconnecting yourself from the bike prior to an imminent crash to avoid becoming irrevocably intertwined with it.

bark—To vomit (synonyms include “toss”, “ralph”, “Technicolor yawn”, “selling Buicks”, “lose your lunch”, “spew”, “hurl”).

base—The level of fitness an athlete attains during the early season that establishes long-distance endurance (see “Target Heart Rate”).

bead—The portion of a tire that rests inside the box section of a clincher rim (see “clincher”) and which is pushed outward by the inflated innertube, then held in place by the hooked lip of the rim’s wall. May be either steel or Kevlar.

berm—A built-up banked turn, either from many bikes going through the turn and building up the dirt, or a human-made bank such as in a dual slalom or downhill course.

biff—Crash.

big air—To catapult the bike into the air in such a manner that you are picked up by local airport radar.

big cookie—Large chainring; excellent after-ride reward, especially chocolate chip.

binder bolt—A bolt, combined with a matching threaded receptacle (wedge, fixed nut, braze-on) that connects, binds, or attaches one or more parts together on a bike. Can be used in conjunction with a hand-operated lever (see “quick release”) to tighten or loosen the seat post to facilitate quick saddle height changes or wheels for quick removal.

bikejoring—A variation on skijoring (being towed behind a car while on skis) whereby a mountain biker is harnessed to a dog or team of dogs by a five to seven-foot lead line and towed.

bio-pace—Originally an elliptical chainring developed by Shimano, it is now a term used to describe the feeling you get from pedaling on a high-pivot swingarm dual suspension bike as the shock is compressed; as the shock is compressed, there is a momentary tugging on the derailleur cage as the rear axle travels rearward and upward, causing the wheelbase to grow slightly. The Bio-pace chainring had a similar feel as one pedaled past the “flat” spot on the ellipse.

blow up—Comes shortly after pushing the body to an extreme level of exertion, and past the limit at which it can maintain an anaerobic pace. One usually cannot recover from blowing up to the same level as just prior to the blowing up. Can be caused by going out too hard too early in the ride, improper warm-up, poor pacing, or nervousness. Happens more easily later in the ride, especially if the muscles are low on glycogen (fuel).

bogus—Stupid; completely unacceptable; a total bummer.

bonding—The joining of two pieces to make a joint using an adhesive and thermal aging; activity in mountain biking where participants simultaneously enjoy each other’s company while riding.

bonding matrix—Thermoset epoxy, the material used to bond carbon fiber strands together for processing into sheets, tubes or lugs.

bonk—When muscles completely run out of fuel, or glycogen, after approximately two hours of heavy exertion, and pedaling becomes almost impossible unless going downhill. Can be cured by eating food high in carbohydrate content.

boot—A small piece of thick but bendable material that is slipped in between the tire sidewall and innertube to temporarily repair a cut or tear in the sidewall.

bottom out—To compress a shock absorber completely under severe load or bump force.

bottom bracket—Primary drivetrain component. Bearing mechanism that rests in the frame and has attached to it the right and left crank arms, allowing them to turn.

braze-on—A fixture that has been welded, bonded, riveted, or brazed (see “braze”) onto the main frame (top tube/down tube/seat tube/head tube) or rear triangle to accommodate accessories such as water bottle cages, fenders, racks, or cable guides.

buff—Nice, dialed (see “dialed”).

bunny hop—A technical bike handling maneuver that causes both tires of the bike to leave the ground, enabling the rider to jump obstacles such as logs, rocks, or downed riders without slowing the bike.

bushwhack—To travel off trail through heavy foliage. Also known as “lost”.

bullet-proof—Something that has been retro-fitted so that it is virtually impervious to damage. For example, using wider rims, heavy duty sidewall tires, heavier gage spokes, and self-sealing innertubes to make wheels bullet-proof.

burley—Big; massive; strong.

butted—When a tubing structural member has a wall thickness that varies across its length. Specifically, it refers to the wall thickness of a bicycle frame’s tube that is thicker near the weld joint, and thinner in the middle. The result is lighter weight, better impact force distribution, and more material at the weld joint for maximum structural integrity.

burn—The feeling one gets in muscles being worked to anaerobic levels (see “anaerobic”). Caused by the muscles burning glucose (sugar) rather than fat due to low oxygen delivery.

cable—The outer sleeve that brake and derailleur control wires run through.

CAD—Computer Aided Design.

cadence—A given rate of revolutions per minute (rpm) of the crank arms/pedals. Optimally, it is 60-80 rpm for off-road riding, except on extremely steep climbs when just getting the cranks around is acceptable.

cantilever brake—A simple, effective bicycle braking system. One brake consists of two vertical arms, bridged at their tops by a mechanism (typically a straddle wire), each with a brake pad, or block, attached, facing inward towards the spokes of each wheel. Each arm is mounted to the frame or fork by individual brake studs, or bosses, which the arms pivot on. As the bridge is pulled on by the brake lever wire, the tops of the arms are pulled toward the wheel’s rim brake surface, which in turn causes the brake pads to come in contact with the braking surface, slowing the bike by direct friction contact. A newer style cantilever has emerged, called the linear pull cantilever (or V-brake from Shimano). Instead of the straddle wire being pulled from the center, the control wire is routed from the side of one of the arms and across to the other via a curved tube. This style of brake is superior to the older center pull cantiliver as it delivers more power and better modulation.

cannibalize—To take parts off one bike to fix or improve another bike. In racing, an illegal practice.

capilene—Similar to polypropylene, it is a synthetic fiber that has a very low density and is used in the manufacturing of non-absorbent, lightweight woven and knitted fabrics. It is excellent as a first layer for cold weather riding as it does not absorb moisture, instead letting the moisture wick to the next layer of clothing and keeping the skin that it is next to dry.

carbon-fiber composite—Long, thin strands of carbon molecules that when combined with a bonding matrix and compaction process, produces a material that possesses high strength, stiffness, and light weight. Its use in the construction of mountain bike frames and components has been heralded as a breakthrough, yet because of its cost is still relatively small compared to chromoly or aluminum.

Cartridge Bottom Bracket—A bottom bracket unit that has its bearings and axle contained in a fixed cylinder.

carve—Also called “rail”, it means to get into a good line and hold it smoothly and forcefully.

cassette—The self-contained cog stack that slides onto a rear hub’s freehub body.

cast—Similar to forging, but without high compaction.

center to center—When measuring bike size, refers to measurement from the center of the bottom bracket spindle to the center of the top tube where it meets the seat tube, in a direct line from the bottom bracket spindle. (Some bike companies measure their bikes center to top of top tube, or center to top of seat tube.)

chain breaker—Also called a chain tool, it is used for pushing the link pin out of the link in a chain to separate links in order to add or remove links, as well as inserting the link pin back into the link plate to re-attach the separated link plates

chainline—The line plotted between the middle chainring and the middle cog on the cog stack, which in theory should be a straight line. Proper chainline is based on measuring from the big chainring to the right side of the seat tube, and also from the small chainring to the left side of the seat tube, then averaging the two figures. Generally, the distance should be 47.5 mm, but differences of as much as a millimeter often occur. Another way to obtain the correct distance is to measure from the tips of middle chainring’s teeth to the centerline of bike (center of BB).

chainstay—The two tubes of the rear triangle on a rigid rear end mountain bike that run from the bottom bracket shell to the rear dropouts.

chainring—Also called a chainwheel, these are the large front gears attached to the right crank arm, forming the drivetrain in conjunction with the chain, derailleurs, cogs, and freehub. The gears vary in diameter (smaller for easy/lower gears, larger for harder/higher gears). Three chainrings is the standard mountain bike configuration, but aftermarket quad (fourth small chainring) attachment devices are also available. With the advent of 9-speed cogs some companies have introduced double chainrings for a less complicated system; however, chainline measuerment is critical with this configuration and the low gear ratios achieved with a triple chainring setup are not available. Chainrings are made from either steel or aluminum alloy. Steel rings (all three) are found on less expensive bikes, while more expensive bikes have aluminum rings, or a combination of steel and aluminum Stainless steel small rings sometimes replace aluminum small rings for increased durability.

chain suck—When the lower portion of the chain’s links do not release cleanly from the chainring, getting carried up and becoming wedged between the chainring and the chainstay. It is caused by a dirty and/or dry chain and/or chainrings, and/or improper shifting technique (too much torque at too slow a speed). Happens most often when lube has been washed away by the chain being submerged in water. Can also occur if chainring tooth has been gouged.

chain slap—The noise a chain makes as it comes in contact with the chainstay in rough terrain.

chamfer—The formation of a slight beveling on a chain link plate to facilitate smoother movement over cogs and chainrings.

cherry picker—A racer who enters a race in a class below his or her skill and fitness level for the sole purpose of winning.

chukkar—One period of play in mountain bike polo.

chromoly—an abbreviation for the steel alloy “chromium molybdenum.” Also abbreviated as chrome-moly, cromoly, or cromo. It is a combination of chromium (a highly corrosion resistant metal) and molybdenum (a high-quality, heavy metal), used in conjunction with carbon and iron to form a steel alloy. Chromium improves the alloy’s corrosion resistance; molybdenum counters the effects of “temper brittleness” during heat-treatment, as well as “weld decay” (a side-effect caused by the presence of carbon). Chromoly possesses excellent strength and modulus of elasticity, as well as being extremely versatile. It is also the most refined material being used in bicycle manufacturing, with over 100 years of use as a frame material. In mountain bikes it is used primarily in the construction of mid to high-end frames and components, although some manufacturers use one chromoly tube (usually the seat tube) in a high-tensile steel frame (see “high-tensile steel”) to give it a perceived edge over all high-tensile steel frames.

city bike—A bike closely resembling a mountain bike, but upon closer inspection is far below the standards that allow true off-road performance. Downgrades in components include high-tensile steel frame, heavier/flimsy components, lack of low-ratio (hill-climbing) gears, tires with smoother tread patterns for decreased rolling resistance on pavement, upright riding position.

chamois—From the earlier days of cycling, the fine leather liner found in cycling shorts to absorb moisture, which is no longer used. The term has become the generic description for the synthetic liner found in today’s cycling shorts. Short liners provide better moisture absorption than chamois leather, as well as providing a chafe-resistant layer that prevents skin and/or genital irritation.

classic—Race format that originated in the late 1970’s that consists of a single long loop of between 20 and 60 miles, or even a point-to-point (different finish area than start). Course is usually cross- country with a varied combination of uphill, downhill, and singletrack.

cleaning a section—Making it through a specific section of technical terrain without stopping or putting a foot (or arm, or body) down.

cleat—Can either pertain to extensions from the sole of a shoe that aid in traction while walking in loose dirt (like football cleats), or the component that is attached to the sole of the shoe that is inserted into the binding mechanism of a clipless pedal.

clipless pedal—A pedal which uses a mechanical retention system whereby the shoe is held in place by inserting a cleat into a binding.

clunker—The first mountain bikes, so named because of the sound the conglomeration of parts made while riding.

cluster—The set of five, six, seven, eight or nine cogs (rear gears); also called a cog stack.

Clydesdale—Special racing class for riders over 200 pounds.

CNC—“Computer numerically controlled”, as in CNC machining.

cockpit—Also called the rider compartment, the area comprising the saddle and the handlebar.

cogs—Also called sprockets, a series (stack) of toothed wheels located at the right side of the rear wheel’s hub. On newer mountain bike drivetrains, they are usually configured in stacks of seven, eight or nine cogs in incremental tooth sizes, while older drivetrains and city bikes usually have five or six-cog stacks. Each cog represents a different gearing range when used in conjunction with one of the three front chainrings.

coil over oil shock—A shock absorber unit that uses a coil spring as its spring medium, and a piston which forces oil through internal chambers for compression and rebound damping control. The coil spring is outside the oil chamber, hence the name “coil over oil.”

combination tire—Any knobby tire that has a raised center ridge, either staggered knobs or a smooth constant ridge, for use on pavement as well as off-road 

complex carbohydrates—Essentially, foods that contain the materials that the body metabolizes as fuel for muscles. Found primarily in fruits, green leafy vegetables, potatoes, pasta, legumes (beans) and whole grains (wheat, brown rice).

composite—In cycling terms, the combining of two or more types of materials which are in and of themselves not structural in nature to produce a new structural material (see “carbon fiber composite”).

contact patch—The surface area of contact between a tire and the ground at any given time.

Control wire—Also known as an inner wire, the braided wires used to control the brakes and derailleurs.

cosmic—A relaxed, almost heavenly state of being.

cramp—The sudden contraction of muscle(s) caused by extreme exertion and dehydration.

crater—Used as a verb, it means to crash, as in leaving a crater.

cooked—muscles that are completely exhausted, also known as “baked”, “fried”, “torched.”

counter steer—To create better traction and control, the rider puts the inside foot out and pushes the bike to a more upright position while leaning the inside shoulder into the turn to produce a countering effect against the bike leaning into the turn.

crank arm—Primary drivetrain components that pedals and chainrings (right side) are attached to, and that attach to the bottom bracket spindle (axle).

crankset—Both crank arms, and chainrings.

crash rash—A relatively superficial abrasion caused by making contact with the ground while still maintaining forward momentum. Also known as a strawberry.

cross up—Aerial maneuver, to turn the handlebar/front wheel while in the air. Used to change the direction of the front end, or trajectory of the bike when combined with body English. Also a flashy trick for the cameras.

crotch clearance—Also known as “stand-over height”, the amount of clearance between the top tube of the bike and the top of the inseam while straddling a bike flat-footed over the middle of the top tube.

cruise—To ride at an easy pace.

cyclo-cross—Cycling sport that combines riding off-road with running and  jumping hurdles or up un-rideable hills. Originated as an off-season activity for road racers. A true cyclo-cross bike is similar to a road bike, but uses cantilever brakes, narrow knobby tires, and bar-end shifters, but over the past several years mountain bikes have been used to great success, to the point that some feel they have an unfair advantage.

dab—Generally speaking, taking your foot or hand off the bike and touching it to a fixed point (ground, tree) to maintain your balance. In Observed Trials competition, is pertains specifically to a scoring penalty when this action occurs.

damping—In suspension, the speed at which a shock absorber’s compression and/or rebound is controlled.

declination—The difference between true north and magnetic north.

derailleur—Primary drivetrain component that moves the chain from one chainring or cog to the next.

dermabrasion—The process of skin being removed from the body as it is sliding over the terrain surface.

dialed—To fine-tune your bicycle or riding style to a state of virtual perfection. As in, “He’s got that trail dialed.”

disc brake—A brake that uses a rotor and mechanically or hydraulically operated pads in a self-contained unit.

dish—The centerline of the rim over the hub and between the locknuts of the axle. A front hub has an equal dish, while a rear hub may have biased dishing on the drive side to accommodate the cogs.

double jump—A terrain surface that causes a jump that has two bumps with a valley in the middle. Typically found on dual slalom and downhill race courses.

double track—A narrow, unimproved vehicle dirt road that has parallel tire grooves.

double wall rim—Also known as a “box section” rim. A rim that uses two walls for the spoke nipple area, creating a box-shaped cross section. Stronger than a single wall rim.

down tube—The lower tube on a bicycle frame’s front triangle that connects the head tube and bottom bracket.

downshift—Shifting the gears from a higher to a lower, or easier, gear. Downshifting occurs when climbing a hill.

drafting—When one rider follows closely behind another so that the lead rider is breaking a hole in the wind for the following rider, making pedaling easier for the following rider. Also called “slipstreaming.”

drivetrain—The crankset, bottom bracket, cogs, chain, pedals, and derailleurs.

Drivetrain Induced Shock Compression (DISC)—When a rear suspension’s shock is compressed under pedal power. Occurs on rear suspension designs that have a low pivot.

driving hypotenuse—A measured distance of leg extension in the power stroke portion of pedaling, determined by the distance between the top of the saddle intersected by the line of the seat tube and the center line of the pedal spindle when the crank arm is perpendicular to and forward of the seat tube.

drop-off—A sharp difference in terrain where the lower section drops away steeply from the upper section, much like a stair step. Usually used to describe a downhill section of terrain.

dropout—The parts in a frame where the axles of the hubs reside (tips of the fork blades and where the chainstays and seatstays meat).

dual suspension—Any bike that has front and rear suspension units.

durometer—The measure of firmness in a cast elastomer or micro-cellular urethane spring.

eating it—Much like “auger.”

effective top tube length—On mountain bikes that use a sloping top tube (see “sloping top tube”), the measurement of the top tube if it were measured on a horizontal plane between the head tube and the theoretical meeting point of the seat tube.

elastomer—Used primarily in suspension systems as the spring medium, it is a plastic material that is cast. When compressed it will return to its original shape. Stores high amounts of energy and rebounds quickly.

endo—When the rear end of the bike comes up with the front wheel still on the ground to the point that it propels the rider over the handlebar.

epic—Monumentally long, arduous ride where participants usually run out of food and water well before the end and go through a range of emotions, from ecstasy to misery to wanting to kill whoever thought of the ride in the first place; a really great ride. Also a ride that has been designated by the International Mountain Bicycle Association as one that is exceptionally beautiful and significant.

etiquette—The common sense ethic of being courteous to each and every backcountry user you encounter. A good rule of thumb is to always approach every corner as if there will be someone coming from the other direction.

extrusion—The final result of a piece of metal that has been pushed through a “die,” or special form, creating a long rod or bar with the outer diameter’s shape looking like the shape of the die’s inner diameter.

face-plant—A combination of “auger” and “soil sample” whereby in a crash, the face is the first thing to come in contact with the ground.

fall line—The direction straight down a hill.

fanny pack—A pouch worn as a belt which positions the storage compartment at the small of the back, above the butt. Usually small, but can also be larger for longer rides to carry extra food, clothing, tools, maps, etc.

fat tire flyer—Early mountain bike nickname; the first modern day mountain bike magazine.

ferrule—Outer cable end-cap that inserts into a cable stop.

fillet brazing—Pronounced “fill-et” (not “fill-ay”), a method of joining tubes or attaching frame parts that uses metals that have a lower melting point, such as brass or silver. Characterized by a very smooth tubing joint, the technique requires a high degree of skill. Very few bikes are produced using this method, and are only available through custom builders.

fire road—Wide (two-vehicle width), bull-dozed and packed dirt road that allows fire fighting and ranger vehicles access into the backcountry. Also serves as fire break. Common in areas with high fire danger.

flip-flop stem—A threadless handlebar stem (see “stem”, “threadless”) that has a two-piece handlebar clamp face that allows the handlebar to be removed from the stem and the stem to be flipped over without having to remove the shifting and braking controls.

forged—The formation of a component or part of a component by either pouring material (aluminum, steel) in a molten state into a mold (“melt” or “warm” forging) and then compressing, or compressing the material in a solid state via a high pressure press into the desired shape (cold forging).

fork steerer—The tube that is connected to the fork crown that inserts into the bike’s head tube, which also has connected to it the stem and headset (see “threadless steerer”, “headset”)

fork crown—On either a rigid or suspension fork, the top of the fork just below the head tube where the fork blades (or “stanchions” on a suspension fork, see “stanchions”) and steerer meet.

freehub—Primary drivetrain component, a newer version of the freewheel where the freewheeling mechanism (ratchets, pawls) are attached to the hub via an internal bolt, with the cogs sliding onto the body via a splined surface. Allows the hub bearings to mount farther outboard for better load disbursement.

free-ride—From the snowboarding term; used to describe either a type of mountain bike with longer travel (see “travel”) for a variety of terrain conditions, or the kind of terrain you would find in an all-day epic ride (see “epic”). Also known as “adventure riding.”

freewheel—Cogs and ratcheting mechanism are contained as one piece (cogs removable), which threads onto the hub.

front-center—Distance measured from the center of the bottom bracket spindle to the center of the front axle.

fully active—A rear suspension that works while the rider is either in or out of the saddle, and does not totally lock out under braking.

gear inch—Number that equates to a particular gearing combination on a bike with derailleurs, representing the diameter of a wheel a 19th century “high wheeler” bicycle would need in order to cover the same amount of ground with one revolution of the wheel.

gear spacing—The spaces between each cog or chainring.

gearing spread—The total range of gears available in a multi-speed drivetrain configuration from the lowest to the highest ratio.

geometry—The combinations of vertical and horizontal angles and lengths of tubes that make up the way a frame handles.

ghost ride—A bike that rides by itself for several yards, typically after a crash where the rider loses contact with the bike.

gimp—Injured but not out of commission.

glycogen—The fuel your muscles use for endurance and power. Created by the ingestion of carbohydrates.

gnarly—Can be used to describe terrain or a trail that is either technically demanding, rough, fun, scary, or all of the above.

gonzo—Used to describe a rider who rides with an apparent disregard for his or her own safety, whose luck is in greater supply than talent, or whose riding style is constantly at the edge of control.

Gore-Tex—A breathable waterproof membrane-like coating used to treat outdoor products and clothing. Also used in Ride-On derailleur cables as an inner sleeve for smoother shifting.

gram-aholic—A mountain biker who will buy the lightest part or component for their bike, even to the detriment of performance and safety. Also known as a “weight weenie.”

granny gear—Small chainring, used mainly for climbing. Also known as a pixie gear.

Grip Shift—The most popular brand of the twist grip-style derailleur shifting system, consisting of indexed rotating grips located inboard of the handlebar grips.

gruppo—Italian, pronounced “groop-oh”, it refers to the traditional component group, comprised of the drivetrain, brakes, shifters, and hubs, but can also include the headset and seat post. Gruppos are usually made by one company (or are at least branded as such) and are designed to integrate the components according to price level, quality, durability and performance.

gurn—Also called a “digger”, an injury characterized by a chunk of skin or flesh being forcibly removed by a part of the bike or ground during a crash or momentary lapse of coordination.

hairball—Crazy, defiant of danger. Derived from downhill great Greg Herbold.

hammer—To exert an extreme amount of energy.

hammer head—A rider who has only two speeds; fast and faster.

hard core—A rider that lives, eats, and breaths mountain biking.

hardtail—A mountain bike lacking rear suspension.

harsh—Not good.

head tube—The short section of tubing on the main triangle that houses the fork’s steer tube and has connected to it the top and down tubes.

heat treatment—A thermal process (sometimes combined with a chemical wash) that brings a specific material, such as aluminum, to a particular temper, or hardness rating.

high-tensile steel—A steel alloy that has a high carbon content. Not quite as stiff as chromoly, so it requires more material to achieve the same strength qualities, making it bit heavier than chromoly.

hike-a-bike—A section where the rider is forced to dismount and push and/or carry the bike. Also known as portaging.

hitting the wall—Running out of energy. Also known as “bonking.”

honking—A riding technique whereby the rider raises up off the saddle and, while pedaling, exerts an increased amount of energy while pulling on the handlebar in a side-to-side motion. It is used when the rider wants to stay in the same gear and use momentum and power to climb a hill, instead of shifting into an easier gear and pedaling while seated.

hooked up—To have good traction, with either the rear tire during climbing or while cornering.

hub—The component that allows the wheels to spin, and that the spokes are attached to.

Huffy toss—A contest in which contestants try to toss a bike for distance. Huffys are predominantly used because of their excessive weight.

hybrid—A bicycle that combines the sturdiness, wide gear range, upright riding position, and secure controls of a mountain bike, with the speed and reduced rolling resistance of a road bike’s narrow tires and wheels. Some hybrids are designed to accommodate wider off-road style tires, making them adaptable to a wider variety of terrain. It is not, however, designed to handle severe off-road riding, nor is it able to attain the speeds of a road racing bike. Also known as a “cross bike”, not to be confused with a cyclo-cross bike.

Hyperglide (HG)—A series of ramps formed into Shimano-brand cogs which help the chain move from the smaller to larger cogs.

indexed shifters—Gear shift controls which use a system of individual detents (measured stops) which allow the operator to feel and hear the shifter as it shifts into the various gear combinations.

inner wire—The wire that comes from either brake or shifter controls that allows the brakes and derailleurs to be operated by the rider.

Interactive Glide (IG)—Similar to HG, but aids the chain in moving from larger to smaller cogs and chainrings.

interference fit—Also called “press fit,” it is the method of forcing two pieces of material together whose mating tolerances are so close that when they are press-fit together, they are forced against and on to each other to secure them. A bonding agent is usually also used in conjunction with an interference fit.

interval training—Also called anaerobic training, this specific training technique increases strength and recovery of the heart by pushing it to its maximum heart rate (MHR) repeatedly (usually approximately 30 second intervals), followed by a controlled recovery period after each MHR period (usually getting the heart back down to around 120 beats per minutes for approximately 2-3 minutes).

investment casting—Also called “lost wax process”, it is a casting process used to create small, detailed parts. First, a wax plug is made, then dipped into a solution that creates a thin ceramic shell. Next, the shell is heated and the wax is poured out, and then molten metal is poured into the shell. Finally, after the metal has cooled, the shell is removed to reveal the metal piece.

joust—The term used to describe the first play on the ball in a chukkar of mountain bike polo.

J.R.A. (Just Riding Along)—Usually used to describe to a bike shop or sales representative the riding conditions prior to a major failure: “I was just riding along on a smooth fire road when my fork snapped.”

Kamikaze—Name of the famous downhill at Mammoth Mountain ski area in Mammoth Lakes, CA; a mountain biker who apparently values speed over his or her life.

Kevlar—A synthetic fiber developed by DuPont that has a tensile strength that is greater than steel, but is also lighter than steel. It’s used in a variety of mountain bike applications, from tire beads (see “bead”) to tire casing belting for penetration resistance, to saddle covers, to carbon fiber structural reinforcement.

knobby—An off-road tire that has a deep, aggressive lugged tread pattern for riding in dirt conditions.

land access—A catch-all phrase that generally refers to the pursuit of gaining or maintaining access for mountain bikers to public back country riding areas. Typically used by local, regional, and national volunteer or non-profit organizations to describe their efforts regarding opening closed trails to bikes, getting newly built trails designated as open to bikes, trail building and maintenance, etc.

lateral flex—Inherent side-to-side bending that occurs on a bicycle frame.

line—The direction of travel through a given turn or section by bike and rider, usually expressed as the desired path of travel: “I had a really good line through that turn.”

link plate—Components on a chain that make up the box section link, held together by link pins. There are inner and outer link plates depending on the section of connected chain. Each link is actually made up of four link plates, two for the outer link and two for the inner link.

link pin—The component of a chain that joins the inner and outer link plates.

lock up—When tires skid because the brakes are applied too heavily, especially on steep, loose descents.

loop—To go over backward on the bike while still seated and holding onto the handlebar; a lap of a race course.

lug—A frame component that acts as a sleeve which various tubes are inserted into, then a bonding process is applied. With the advent of TIG welding, very few if any steel mountain bikes use this technique any longer as it is more difficult to fabricate because of the additional lug pieces, as well as being heavier. However, in carbon fiber frame production, lugs are molded out of either aluminum or carbon fiber, and carbon fiber tubes are then bonded to the lugs, creating a very stiff, strong frame.

Lycra—Brand name for Spandex, a synthetic fiber used to produce a wide range of elastic yarns used in woven and knitted fabrics and garments, most notably cycling shorts. Lightweight and breathable, this material can conform to a variety of shapes and has amazing stretch memory, being able to return to its original shape and dimensions after being stretched to up too 600% of its surface area.

mag—Short for magnesium alloy, it is used in several suspension fork manufacturers’ products.

main frame—Also called the “front triangle”, it is the structure consisting of the head tube, down tube, top tube, bottom bracket shell, and seat tube.

Maximum Heart Rate (MHR)—The maximum at which your heart will beat, which you can also estimate by subtracting your age from 220. This is simply a guideline for someone exercising for the first time, or getting back into shape after a long lay-off. A better approximation of maximum heart rate is to exert yourself for approximately five minutes to an anaerobic level, and then record your highest heart rate. Rest for approximately 10 minutes and repeat, then take the average of the two maximum heart rates for your own maximum heart rate figure. A stress test done by trained medical personnel can also determine a more accurate MHR.

Micro-Cellular Urethane (MCU)—A more advanced version of cast elastomer. Used as the spring medium in suspensions, it is cast urethane which contains thousands of tiny air pockets. Its compression and rebound properties can be tuned more precisely through the use of these air pockets.

minute—One 60th of a degree of latitude or longitude.

miter—To cut and/or file a piece of metal so that it fits precisely against or along another piece, usually in preparation for welding.

modulation—While braking, the sensitivity of the brake system to be able to exert force upon the rim with varying pressure while still maintaining control.

modulus of elasticity—The stiffness of a given material as it reacts to a measured impact or force.

monocoque—A one-piece carbon fiber main frame, or aluminum main frame shaped from sheet aluminum rather than tubes.

mountain bike—Also known as an All Terrain Bike (ATB), this bike possesses a number of specialized features that enable it to be ridden off-road on dirt roads, paths, and trails, as well as on terrain that the operator would not attempt on anything else but a mountain bike. The specific features include but are not limited to the following: Rugged, sturdy frame that can handle heavy impacts, with rigid or suspension fork and possibly rear suspension; large air volume “knobby” tires; upright handlebar with brake levers and shifter controls on handlebar within easy reach; wide gear range drivetrain; powerful cantilever brakes.

mountain biking—Outdoor activity characterized by high levels of fun, camaraderie, and communing with nature while on a mountain bike.

Mountain Bike Polo—An activity that is popular at mountain bike festivals, this game mixes equestrian polo and mountain bikes, with teams of contestants using long mallets and a ball to score points.

mudsnake—Mud or moss-covered low lying root or small deadfall limb that lies diagonally across trials that cause the tire(s) of a mountain bike to slip out, usually tossing the rider

mulch—To completely destroy a component as to render it useful only as plant food, as in “I just mulched my derailleur”.

munch—Same as “mulch.”

multiple use—A trail or area that has been designated for use by all user groups (hiking, equestrian, mountain bike).

needle bearing—A type of roller bearing that uses cylindrical bearings rather than ball bearings. The bearings are typically encased in a conically mounted race.

negative lean—See “counter steering”; this is not as aggressive as a counter steer in that the shoulder leans into the turn as the bike is maintained in a more upright position for better traction.

NORBA—National Off-Road Bicycle Association, the U.S. governing body of mountain bike racing.

observed trials—A type of mountain bike competition where contestants try to ride their bikes through a designated course, either natural terrain, human made, or both, without touching a foot, hand, or shoulder to the ground or other fixed obeject.

orienteering—A competition in which participants race to complete a circuit of target points using only a map and a compass for navigation.

O.T.B.—Off The Back, as in being left behind by the rest of the pack.

outer cable—Also called “cable housing”, it is the flexible plastic housing that encloses the brake and derailleur control inner wires.

oversized—In bicycle frame tubing, increasing the outer diameter of the tube to increase structural strength and decrease wall thickness for overall lighter weight without sacrificing stiffness.

pace—The current speed of an individual or group; to control your energy output during a ride or race.

pannier—French, pronounced “pan-yáy”, saddle bags mounted on the front or rear of the bike via racks that efficiently carry heavy loads for commuting or touring.

pawls—Spring-loaded claws located within the freehub or freewheel that engage steps as they are driven forward by the pedals and the chain, allowing the rear wheel to receive torque (power) from the drivetrain.

pedal body—the main part of a standard pedal that houses the spindle and bearings. Less expensive pedals have a one-piece molded body and cage

pedal cage—Also called the “platform”, it is the structure that surrounds and is attached to the pedal body.

peening—The process of mushrooming the ends of a chain link pin to assist in retention of the link plates.

penetration—A term used in frame fabrication that refers to the amount of metal being burned when joining tubes by TIG welding.

pinch flat—Also known as a “snake bite”, it is the result of a tire hitting a sharp obstacle which in turn compresses the tire to the rim, with the innertube getting pinched in between and receiving a cut that results in loss of air. The ‘snake bite’ comes from when the tire hits the obstacle so hard two parallel cuts occur from both sides of the rim.

point rider—The lead rider in a group; a rider that has been sent ahead of a group as a scout to inspect terrain and alert other trail users of the group’s approach.

point-to-point race—A “classic” race format where racers end at a different location, usually quite far away, from where they started.

polypropylene—Also called “polypro”, a synthetic fiber that has a very low density and is used in the manufacturing of non-absorbent, lightweight woven and knitted fabrics. It is excellent as a first layer for cold weather riding as it does not absorb moisture, instead letting the moisture wick to the next layer of clothing and keeping the skin that it is next to dry.

portage—see “hike-a-bike.”

poser—Has all the cool stuff but doesn’t/can’t ride. Also known as a “wanna-be”, “dweeb”, or “fred.”

power stroke—The portion of the pedal revolution where power is greatest, from around the top of the revolution to the bottom.

pre-load—Increasing the amount of pressure on a suspension’s spring to change the ride characteristics or sag rate (see sag).

proportional geometry—The fine adjustments made to a frame’s angles and tube lengths so that all sizes of a model of a bike have relatively identical rider compartments and handling characteristics.

proportional sizing—Outfitting the bike with parts that match the anatomical specifications of the person who will be riding that particular size of bike, i.e., shorter cranks on smaller bikes.

pucker factor—The degree of clenching of the sphincter muscle just prior to crashing

psi—“Pounds per square inch”, this refers to the amount of air pressure that is in a tire’s innertube at any given time. Suggested psi pressure range is typically located on the sidewall of the tire. Lighter riders can run a lower pressure, while heavier riders should run closer to the maximum psi.

pulley wheel—also called a “jockey wheel”, it is one of the two gear-like wheels located below the derailleur’s pivoting body which the chain passes over.

pulley wheel cage—The parallel plates that hold the pulley wheels located below the rear derailleur’s pivoting body that allows the chain’s tension to be controlled while in the various gear combinations.

quick release—Also known as a “QR”, this mechanism is used to hold a wheel’s hub in the frame or fork’s dropouts. It consists of a narrow axle, called the “skewer” which is threaded at one end to accommodate a nut and is inserted through the hub’s hollow axle, and a cam lever at the other which exerts a clamping force onto the dropouts to retain the wheel. A similar device is also used on many bikes to hold the seat post in place, making it simple and easy to raise or lower the saddle height.

quill—The portion of a stem that inserts into the fork’s steer tube. See also “wedge bolt.”

rad—Short for radical; good; extreme; fun; amazing.

RapidFire Plus—Shimano’s integrated under-the-handlebar (“underbar”) shifting controls/brake levers which consist of dual levers, one for the thumb and one for the forefinger.

ratcheting—A pedaling technique that uses partial backpedaling during the pedal stroke to keep the pedals from making contact with obstacles on the ground, or to set the pedals up for optimal power delivery in tight trail conditions.

reach—The distance between the brake lever and the handlebar grip. More expensive levers have adjustable reach to accommodate smaller hands; the distance from the steer tube and handlebar clamp of the stem.

rebound—The act of suspension returning to its original position from being compressed.

Rest and Recovery Range—By factoring 60 to 65 percent of your theoretical maximum heart rate (220 minus age) and adding resting heart rate, you can determine the heartbeat range that reflects the minimum exertion level desired for recovery rides after high intensity workouts. For example, a 35 year old would take 220 minus 35 to get 185, then multiply by .60 to get 111. If the person’s resting heart rate is 45, the Rest and Recovery Range would be 161.

Resting Heart Rate (RRR)—Heart rate at complete rest, as in completely relaxed and asleep. Should be taken immediately after waking up while still lying prone.

retro-grouch—A rider who prefers to not only disdain new technology, he or she actually prefers older equipment and will frequently complain about the proliferation of technological advancements.

rider compartment—The area consisting of the distance between saddle and handlebar.

rig—To fasten, fix, or secure a part or parts by means other than their original method.

rim brake—Any brake that generates frictional force for slowing or stopping the rim by mechanically moving brake pads into contact with the braking surface of the rim. Typically, a cantilever.

rise—The distance in elevation measured vertically from the steer tube to the handlebar height.

rising rate—Term to describe a characteristic in a suspension system that, as the compression nears maximum, the spring rate gets firmer (slows down), reducing the likelihood of a harsh bottoming out or sharp force to the rider.

roller—The bushing or bearing component of a chain that allows the links to be flexible linearly, and are connected to the links by link pins.

rolling terrain—Terrain that is mildly to moderately steep and continually up and down.

rolling resistance—The frictional resistance of a tire’s contact patch as it rolls on the ground. The larger the contact patch and/or lower the tire pressure (psi), the greater the rolling resistance.

romp ’n stomp—A non-competitive event that purposefully combines mountain bikes and equestrians on the same dirt roads or trails.

rookie mark—The big gooey chainring mark left on the right calf of less coordinated riders.

roost—From “rooster tail”, a general term that means either a dirt plume generated by the rear tire, or to go fast (see “shred”).

rotational direction—The suggested direction of rotation on a wheel-specific knobby tire (see “wheel-specific”).

saddle height—the optimum distance of the saddle’s height for proper leg extension.

sag—The amount of initial shock travel while at rest when a rider is aboard. Used to allow the effected wheel to rebound and follow terrain more closely.

sand-bagger—See “cherry picker.”

schwag—Free stuff.

Scott Trials—Named after Alfred Angus Scott, an early British motorcycle manufacturer and inventor who popularized the format, and which was the predecessor of motocross. In mountain biking, it is a combination of a cross country time trial and trials riding. Within a short course of no more than five miles, several stock-bike level sections are established. Scoring is a combination of time and dabs.

seat pin—A recessed nut and bolt combination that clamps the seat tube to keep the seat post from sliding up or down. Lighter than a quick release but not as quickly adjustable.

seat tube—The tube on the main triangle of the frame that has connected to it the top tube, bottom bracket, and seat and chainstays. It is also the tube that the seat post slides into.

seatstay—The two lower tubes of the rear triangle that attach to the bottom bracket and contain the rear dropouts.

semi-slick tire—A tire which uses a smooth or lightly knobbed center section with knobbies at the outer portion of the tread. Not recommended for loose dirt or hard-packed surfaces with rocks or sand.

shared use—See “multiple use.”

shifting cables—See “inner wires.”

Shimano Pedaling Dynamics (SPD)—The original mountain bike clipless pedal system (or at least the first successful one) using a spring-loaded mechanism much the same as a ski binding to hold a cleat which is attached to the bottom of a cycling shoe onto the pedal. Sometimes called “spuds.”

shred—To take complete control of the riding surface or situation.

shuttle—To park one car at the bottom of a hill, take bikes and riders to the top the hill with another car, ride bikes back down to first car, then retrieve second car with first car; an aerial maneuver in which the rider and bike self-destruct in mid-air.

singletrack—As defined by some public backcountry management agencies, a trail with a width narrower than 60 inches. Primarily, a trail so narrow as to have only enough room for a single user, requiring a single file line.

skanky—Disgustingly smelly and dirty.  

sketchy—Trail description meaning it was totally un-rideable and scary but I'm too cool to say that.

skidplate—Also called a “bash guard”, it is a formed piece of metal or high-impact plastic that is mounted to the bottom bracket area of a bike to protect it from damage that may be incurred from the bike’s chainrings coming into contact with hard, immovable objects. Usually used on trials bikes or trail bikes ridden in the Pacific Northwest, or where logs and rocks are common on the trails.

slant parallelogram—The design of rear derailleur’s pivoting body that allows it to track the cog stack precisely and consistently along the entire range of cogs.

Slickrock—Most notable near the southwestern Utah high desert town of Moab, this smooth sandstone rock can be a patch surrounded by dirt, or the predominant terrain make-up of the mountains or hills. Primary characteristics are exceptional traction and efficient dermabrasion.

slick—A completely smooth or lightly grooved tire used primarily for maximizing a mountain bike’s efficiency on the road.

sloping top tube—A top tube that is lower at the seat tube than at the head tube.

Snell Memorial Foundation—A more stringent helmet testing facility than ANSI, requiring helmets to withstand no more than 300 Gs of force when dropped from a two meter (approx. six feet) height onto a flat surface, and from 1.2 meters onto a round surface. The helmet must also pass a chin strap pull-test before being certified.

soil sample—Similar to “auger”, it is the act of taking with you a portion of the ground upon which you just landed.

speed jump—Can also be called a “wheelie hop” or “horizontal bunny hop.” Similar to a bunny hop, except the front tire comes up first to clear an obstacle, followed by the rear tire.

spider—The four-or five-point star of the right crank arm which chainrings are attached to.

spin—Another term for “cadence” or “rpm”, but can also be used to describe an easy pedal cadence, as in “I’m just going to spin today.”

spindle—The bottom bracket or pedal “axle.” On a bottom bracket spindle, it is where the cranks attach and what rolls on bearings inside the bottom bracket shell of the frame. On pedals, it is what attaches to the other end of the crank arms and rolls on bearings inside the pedal body.

split-stop—Cable guide attached to the frame that has a groove down the middle to allow the inner wire and outer cable to be removed from the guide. Primary function is to facilitate re-greasing of the covered section of the inner wire.

spring—The medium which is used to support a suspension system in an open (extended) position; the medium which is primarily responsible for resisting compression forces; also the primary mechanism that rebounds the suspension.

spring rate—The amount of energy needed to compress a suspension’s spring from an uncompressed state to one inch of compression, usually expressed in pounds.

sprung weight—All weight, including the rider’s, above a suspension mechanism’s shock absorber.

spuds—Nickname for SPD pedals.

squirrely—Inconsistent, nervous, erratic, out of control riding style or personality.

stand-over height—Same as crotch clearance, the amount of clearance between the top tube of the bike and the top of the inseam while straddling the bike flat-footed over the middle of the top tube.

stem—The component that connects the handlebar to the fork’s steer tube.

stiction—A combination of “static friction”, the amount of initial friction a suspension unit possesses before the beginning of the compression stroke, and the force it takes to move the suspension.

straight gauge—Describes tubing that has no wall thickness variances along its length.

stylin’—A very smooth and fluid riding style; a nicely presented bike or bike transporter (car). See also “dialed.”

suspension—Mechanism on the front and/or rear of the bike that helps keep the tires in more contstant contact with the ground and reduces bump forces transmitted from the ground through the tires.

switchback—A sharp turn incorporated into a road or trail enabling the track to traverse a steep hill.

table-top—Either a piece of terrain with with a flat-top surface that creates a jump (usually on a dual slalom course), or an aerial maneuver where the rider gets the bike’s frame parallel to the ground while in the air.

tacoed—Also called “potato chipped”, it is the shape of a wheel’s rim after a severe load.

Target Heart Rate (THR)—Used for building the heart’s endurance (“base”), it is the rate at which a given individual should work at for approximately 1-2 hours continuously. The basic formula to determine this rate is 220 minus age multiplied by .80 (80 percent of maximum heart rate). Therefore, a person who is 30 would subtract 30 from 220 to get 190, then multiply 190 by .80 to get 152. 152 is the target heart rate. This is simply a guideline for someone exercising for the first time, or getting back into shape after a long lay-off. A better approximation of maximum heart rate is to exert yourself for approximately five minutes to an anaerobic level, and then record your highest heart rate. Rest for approximately 10 minutes and repeat, then take the average of the two maximum heart rates for your own maximum heart rate figure.

technical—A particularly difficult stretch of terrain, either up or down, that requires a high degree of bike handling skill.

tech weenie—A rider who would prefer to talk about the latest technological advancements that he or she has read about in magazines than actually ride; a rider who has to have the latest in technological advancements; a rider who you try to drop as soon as possible so he or she doesn’t take up all the surrounding oxygen talking about the latest technological advancements they have on their bike or have read about in the magazines.

tensile strength—Also called “ductility”, it is the measured point at which a given material will bend before breaking.

threadless—A headset that uses a system of a steer tube with no threads to connect the headset to the main frame’s head tube. “See AheadSet.”

TIG (Tungsten Inert Gas)-welded—The process of joining various kinds of steel or aluminum tubing together by heating them to a semi-molten state with a welding electrode (Tungsten) as they are bathed in Argon gas (Inert Gas). The gas prevents the weld area from being contaminated by oxygen that may cause the area to be brittle and weak. TIG-welding is less expensive and faster than fillet brazing or lugging, and is easier to work with when welding thick-wall frame tubing. Done correctly, it is also lighter and just as strong as brazing or lugging. For these reasons the vast majority of mountain bike frames are TIG-welded.

titanium—An expensive material that is relatively difficult to work with, It possesses very good tensile strength and modulus of elasticity, corrosion resistance, and is light in weight, approximately 40 percent less than steel. In mountain bike application it is used in frames as well as machined and cast parts and components, and fasteners.  It is typically alloyed with vanadium and aluminum to produce weldability and strength. Frame tubing currently uses around a six percent mix of Aluminum and four percent Vanadium , hence the typical alloy designation “Titanium 6AL/4V”

toe-clips—A combination of a curved piece of metal or, more recently,  high-impact plastic, that is attached to the front of the pedal, which has attached to it and the pedal a nylon or leather strap that retains the foot across the top and from the front and sides of the shoe. The result is a more secure connection to the pedal for improved power transfer and better grip in rough or wet conditions.

top mount shifter—A shifter control that is mounted inboard of the brake lever and on top of the handlebar. Also called a “thumb shifter.”

topographic map—Also known as a quadrangle or “quad”, this map, usually generated by the United States Geological Service, shows elevations and other geographic features, as well as human-made structures and any other land marks that can be seen from the air. Typified by contour lines that delineate elevation gradients.

tooth—The sharp point on either chainrings or cogs that catch the chain and carry it through the drivetrain.

top tube—The upper tube that has connected to it the head tube and the seat tube.

tracking—The act of following a line, or following a rider’s line that is ahead.

traction—Adhesive friction between tire and ground.

travel—In suspension, the amount the given unit will move to accommodate absorption of a bump force.

trail bike—A mountain bike that is more suited to easier, groomed trails or fire roads. It has a more upright riding position and less durable components than a true mountain bike, but better than a city bike.

tweak—To make a fine-tuned adjustment: “I need to tweak my derailleur”; to put something out of adjustment from hard riding, including body parts: “I really tweaked my front wheel (arm, neck, chainring) when I crashed on that jump”; mentally unstable: “He’s kind of tweaked.”

U-brake—A brake developed by Shimano that was first designed as an alternative to the Wilderness Trail Bikes Roller Cam (and later, SunTour Power Cam) brake. U-brakes are very powerful, but require a different brake boss location to accommodate the longer arms.

underbar shifter—A shifter control lever which is located inboard of the brake lever and underneath the handlebar. See “RapidFire Plus.”

upshift—To shift into a higher, or harder, gear. Occurs when increasing speed or descending a hill.

un-sprung weight—All weight below a suspension system’s shock absorber.

V-brake—See “cantilever brake.”

veering—In mountain bike polo, veering occurs when the player rides other than parallel to the sidelines, which therefore excludes the player from play on the ball.

vertical—Elevation gain; to get air from a jump.

VO2 Max—Maximal oxygen intake, a measure of your aerobic fitness.

wall—A hillclimb that resembles a near vertical face.

wanker—British slang for one who masturbates; to lose concentration or general coordination; a rider who is a jerk.

wash—When the front tire loses traction while turning, causing the tire to slide out from under the bike.

washboard—Also called braking or stutter bumps, a series of small (or in some cases large) bumps running parallel to the trail, most commonly found at the entrance to a turn where heavy braking occurs.

way—Total, as in “way cool.”

wedge bolt—The system used in a quill-type stem that incorporates a bolt and wedge-shaped nut. The quill and wedge bolt slide into the fork steer tube and as the bolt/nut is tightened, the nut is drawn up and wedges against the stem’s quill, expanding against the inside wall of the steer tube, holing it in place.

wheel-specific tire—A knobby tire that has directional knobs that improve traction and cornering for the wheel that it is intended to be on (front or rear).

widowmaker—An uphill time-trial on a very steep slope.

Wilderness Area—Land that has been designated under the Wilderness Act of 1964, where special protective considerations are instituted to safeguard the area against human made contraptions in order to maintain the area as undisturbed and pristine.

wired—Similar to “dialed”, in control; state one obtains after having two or more double espressos.

zirk fitting—A one-way valve that allows grease to be inserted into an otherwise closed area, usually a bearing race, so old grease can be replaced with new grease. The fitting has a spring-loaded ball that closes off the entry hole, but when a grease gun is fitted and grease is injected, the ball moves inward to allow passage of the grease.

zoned—As in the Twilight Zone, to lose concentration or focus—“He really zoned that last section.”