Bike tech explained

Your quickfire guide to bike jargon

Bottom bracket

● The bottom bracket connects the chainset (aka crankset) to the bike. It sits inside the frame at the junction of the down-tube and seat-tube and contains bearings that allow the crank arms to spin freely. There are many types, including threaded and press-fit, with sizes of bottom bracket depending on the brand.

Cockpit

● In the main text, it refers to the stem and handlebar. The stem attaches the handlebar to the steerer tube of the bike’s fork.

Disc brakes

● Disc brakes work by pushing a pair of pistons against a disc rotor attached to the wheel hub. Systems can be either mechanical (cable actuated) or hydraulic, for maximum power and control.

Groupset

● All the parts of the bike involved in braking, changing gear or running the drivetrain to move the bike. These include the gear shifters, brake levers, brake callipers, derailleurs (or mechs), crankset, bottom bracket, chain and cassette.

Stack

● The vertical distance between the top of the head tube and the centre of the bottom bracket. A taller stack means a more upright ride position; a lower stack means a lower, or racier, position.

Reach

● The horizontal distance between the centre of the bottom bracket and the centre of the head tube. A longer reach lowers your ride position, a shorter reach means you sit more upright.

SRAM eTap AXS

● eTap is bike-component company SRAM’s wireless, electronically controlled gear system, which has evolved from the brand’s original mechanical ‘double tap’ shifting system. An AXS-equipped drivetrain has no cables: the mechs and shifters have their own batteries. AXS (pronounced ‘access’) enables all of SRAM’s wireless products to communicate, so you can mix and match components from its different groups. SRAM’s electronic drivetrains also have app control and customisation plus a 12-speed cassette.