ALL MOUNTAIN A style of off road riding that incorporates many different types of terrain. This style of riding focuses on being able handle very rough riding, while still being able to climb efficiently.
ALLEN BOLT A threaded bolt with a hexagonal depression in the centre of its head.
ALLEN KEY Hexagonal-shaped tool that fits Allen bolts.
BEARING A mechanism that usually consists of a number of ball-bearings and circular channels, or races. It allows two metal surfaces to move freely while in contact.
BLOCK Sprockets fitted to a freewheel.
BOSS Threaded metal fixture on a bicycle frame to which an item such as a bottle cage or a pannier rack is attached.
BOTTOM BRACKET Rotating unit that connects the cranks on either side of the bottom bracket shell to each other.
BOTTOM OUT A term that describes the point when a suspension fork or shock absorber reaches the limit of its travel.
BRAKE-LEVER HOOD The body in which the brake lever sits, connecting it to the handlebar.
BRAKE TRAVEL The distance a brake lever moves before the brake pads engage the braking surface on the rim or hub of a wheel.
CABLE TIDY A small, soft-metal cylinder that is closed at one end and fits over the cut ends of a cable to prevent fraying.
CASSETTE Sprockets that fit on the freehub.
CHAINRING A toothed ring attached to the cranks that drives the chain and, in turn, the sprockets and the rear wheel of a bicycle.
CHAINSET The assembly of chainrings and cranks.
CHAINSTAY The frame tube joining the bottom bracket shell and rear drop-out.
CHAIN SUCK When the chain jams and bunches up while riding. Usually caused by muddy conditions or worn chain rings.
CLEAT A plastic or metal plate that fits to the sole of a cycling shoe and engages into a clipless pedal to hold the foot on the pedal.
CLIPLESS PEDAL A pedal with a mechanism to engage the cleat on the sole of a cycling shoe and hold it securely in place. Called clipless because they replaced pedals that had toe clips and straps. Using clipless pedals allows the rider to pull up with his/her legs as well as push down.
COG A circular metal object with teeth, sometimes used as an alternative term for sprocket. It usually describes the parts within a hub gear that can be combined to give different gear ratios.
COMPRESSION The action of a suspension system when it absorbs an impact from the terrain. The term refers to the compression of the spring. Could be expressed in terms such as ‘soft’ or ‘hard’.
CRANK The lever that joins the pedals to the chainrings and transfers energy from the rider’s legs into the drivetrain of the bike.
CROSS COUNTRY A style of off road riding that incorporates many different types of terrain with a focus on endurance and climbing. The lightest bikes are the best for this style.