In the early 1980s comedian and keen cyclist Alexei Sayle gave an interview to Bicycle magazine in which he talked about the way bike shops guard their knowledge with language. "You ask for a hub," he said, "and they reply 'cross-threaded or off-flange?' and then they've got you!"
Cycling's technical jargon is one of the biggest hurdles when you're starting out, so here's a glossary of terms to help you out.
Anything we've missed? Let us know in the comments so we can make this listing as comprehensive as possible.
Alloy: A mixture of one or more metals and other elements. Alloying changes the physical properties of the main metal. For example, the common 6061 aluminium alloy used for bike frames contains magnesium and silicon and has a yield strength roughly thirty times higher than pure aluminium.
Aheadset: The original brand of threadless headset. Previously, headsets were adjusted by turning them on a thread on the steerer and holding them in place with a locknut. A threadless headset is held in place by the stem bolts after being preloaded by a bolt inside the steerer.
Bead seat: The part of the rim where the tyre bead sits. The diameter of the bead seat is the basis of rim and tyre size standards. For example the standard road bike wheel and tyre size, 700C, has a bead seat diameter of 622mm
Bearing: Any mechanism that reduces friction to allow parts to move easily against each other. Most common bicycle bearings use steel balls to allow parts to turn easily. Plain bearings, also known as bushings, have low-friction surfaces that slide against each other and are found in some components such as pedals and jockey wheels.
Belt drive: Bike transmission using a reinforced, toothed rubber belt instead of a chain.
Bimetallic corrosion: Aka galvanic corrosion; this is corrosion damage caused by a chemical reaction between two dissimilar metal surfaces and salt water. The most common example is aluminium seat posts corroding in place in steel frames because of the constant washing in salt water this area gets in a British winter.
Bolt circle diameter: The distance across an imaginary circle drawn through the centres of a crank's chainring bolts. Indicative of chainring compatibility, as long as the ring and cranks have the same number of bolts and the same bolt circle diameter, though Shimano's recent dalliance with asymmetrical crank arms made things complicated.
Carbon fibre: Composite material comprising very high strength carbon strands embedded in a resin matrix. Can have an extremely high strength-to-weight ratio and is therefore widely used for high-end bike frames and components.
Chain: An articulating assembly of links and pins used to transmit pedalling force from the chainrings to the sprockets
A Shimano SPD cleat, recessed into the sole of the shoe (CC BY-NC 2.0 Karlos:Flickr)
Clipless pedal: Pedal with a mechanism that engages a cleat in the sole of the shoe to provide a firm attachment for the rider's foot. So called because some pedals have metal or plastic cages — clips — to keep the foot in place on the pedal, usually with a strap around the foot.
Cockpit: Term for the handlebar and stem, and sometimes the saddle and seatpost too, used by pretentious cycling writers who feel the strange need to give the impression they're flying a fighter plane rather than riding a bike.
Drop handlebar: The curved handlebar shape almost universally used on road-racing bikes and bikes that follow race bike styling such as touring bikes and gravel bikes.
Dropper post: A seatpost that includes a spring-loaded telescopic height-adjustment mechanism. Common on mountain bikes and sometimes seen on drop-handlebar gravel bikes.
Freehub: Rear hub which includes the freewheel mechanism in its structure. The sprockets slide on to the freewheel and are held in place with a lockring. Has largely replaced the previous standard of a separate freewheel that screwed on to the rear hub.
Fridge suck: The most powerful force in the cycling universe is the attraction between any small object dropped while working on a bike and the most inaccessible point under a nearby large object, such as the exact centre of the space under the fridge. This force increases with the level of groddiness of the crud under the fridge. It can be cancelled out for steel parts by the ownership of a magnetic pick-up tool.
Gear hanger: The part of the frame the rear mech is attached to. Usually part of the right hand side rear drop-out. On aluminium and carbon fibre frames, the gear hanger is removable so that a crash that damages it doesn’t write off the whole frame.
Hairsine ratio: The ratio between the weight saved by fitting a lightweight component and its cost. Named for Jon Hairsine, a rider prominent on the early British mountain bike racing scene. When asked how much he'd cut off a new carbon fibre handlebar to trim its size and weight, Jon replied: "About five quid!"
High gear: High gears on a bike come from the combination of a large chainring and small rear sprocket. That results in multiple turns of the rear wheel for each turn of the pedals, allowing high speeds.
Higher/lower gear range: Road bikes tend to have higher gears overall, hence they are referred to as having a high gear range, while the lower top and bottom gears of a mountain bike mean that it has a lower gear range.
Locking compound: Liquid used to 'lock' threads together. Loctite is the most common and comes in various grades according to the size of threads being joined and how permanent the attachment needs to be. Also known as threadlock.
Low gear: Low gears on a bike come from the combination of a small chainring and large rear sprocket. That results in fewer turns of the rear wheel for each turn of the pedals, allowing low speeds for climbing hills.
Lycra: General term for stretch fabrics used for cycling and other sports clothing. The name comes from the elastic fibre that’s woven in with another yarn such as nylon or polyester usually in a mix that’s about 18% Lycra and 82% nylon. While the term has become generic, Lycra is a DuPont trademark; other manufacturers refer to it as spandex and elastane.
Power meter: An electronic device that uses gauges to measure pedalling force and from that calculate the amount of power the rider is generating as she rides. Typically built into the cranks, pedals or bottom bracket axle, sometimes in the rear hub or chainrings.
Quick release: A mechanism in the hub which allows the wheel to be easily removed and fitted without tools. A rod passes through a hollow axle and is tightened with a cam lever that clamps the drop-outs.
Quill stem: Handlebar stem that inserts into the fork steerer, rather than clamping around it. Usually used in conjunction with a steerer and headset that adjust by means of threads on the outside of the steerer.
Q-factor: The width of a pair of cranks, measured at the pedal eyes; the distance between the outer surfaces of the cranks at that point. Some riders, especially shorter people, find they are more comfortable with a smaller Q-factor. Also used to designate the distance between the outboard end of the pedal thread and the centre of the pedal mechanism.
Seat post: The component that supports the saddle. Usually held into the frame by a clamp at the top of the seat tube, though some high-end frames have the seat post integrated into the frame as an extension of the seat tube.
Side-pull brakes: Brakes that attach to the frame above the tyre and are actuated by a cable at the side of the mechanism. Probably the most common brake design on road bikes, but increasingly supplanted by disc brakes on new bikes over around £1,000.
Spokes: Shaped rods that connect the hub and rim of the wheel. The tension in the spokes gives the wheel its strength and ability to support loads far in excess of its own weight. Spokes are most commonly made from stainless steel, but may also be made from titanium, carbon fibre and aluminium.
Sprocket: A toothed wheel that meshes with a chain or toothed belt to transmit power from one part of the bike to another. Usually used to refer to those on the rear wheel; sprockets on the crank are called chainrings. Not to be confused with cogs, which mesh with each other.
Square taper: A design of bottom bracket and crank. The left and right cranks are separate from the bottom bracket axle. The ends of the axle are square in shape and tapered. Cranks mount via matching holes and are pulled into place with bolts. A tool called a crank puller is necessary to remove a square tape crank.
Squirrel: Arboreal rodent often encountered while riding. (Happy now, hawkinspeter?)
Stack and reach: The vertical and horizontal measurements from the centre of the bottom bracket to the top of the head tube. The most accurate indicator of how a bike will fit, but still only gradually coming into widespread use.
Steel: An alloy of iron and carbon, often with other elements added to tailor its properties. There are many varieties of steel, from simple carbon steel, composed of just iron and carbon, to alloy steels used for bike frames which usually have chromium, molybdenum and manganese alloying elements.
Steerer tube: The upper tube of the fork. Sits inside the head tube and is held in place by the headset bearings which allow it to turn. The handlebar stem attaches at the top of the steerer, clamping inside or around it depending on the design.
Trail: The horizontal distance from where the front wheel touches the ground to where the steering axis intersects the ground, as shown in the above diagram. Trail affects handling; more trail makes a bike more stable at speed.
Tubeless: Tyres that have no inner tube but retain air because they fit very tightly on the rim, the rim is sealed by a special rim strip and the tyre either has an internal rubber coating or contains a liquid sealant that both coats the tyre and seals small punctures.
Tyre bead: The wire round the inside of a tyre. As well as supporting the tyre shape, the bead hold the tyre in place on the rim. In most tyres the bead is made of steel; in lightweight tyres Kevlar is used to save weight, which also makes the tyre easy to fold for storage.
Woods valve: Tyre valve with a removable mechanism held in place by an external collar. The top thread is the same as that of a presta valve, so threaded pump adapters can be used, but it's usually too short for a press-fit or clamp-on pump head such as those usually found on track pumps. Also known as a Dunlop valve or English valve, though they're now very rare on anything but utility bikes intended for the Netherlands market.
John has been writing about bikes and cycling for over 30 years since discovering that people were mug enough to pay him for it rather than expecting him to do an honest day's work.
He was heavily involved in the mountain bike boom of the late 1980s as a racer, team manager and race promoter, and that led to writing for Mountain Biking UK magazine shortly after its inception. He got the gig by phoning up the editor and telling him the magazine was rubbish and he could do better. Rather than telling him to get lost, MBUK editor Tym Manley called John’s bluff and the rest is history.
Since then he has worked on MTB Pro magazine and was editor of Maximum Mountain Bike and Australian Mountain Bike magazines, before switching to the web in 2000 to work for CyclingNews.com. Along with road.cc founder Tony Farrelly, John was on the launch team for BikeRadar.com and subsequently became editor in chief of Future Publishing’s group of cycling magazines and websites, including Cycling Plus, MBUK, What Mountain Bike and Procycling.
John has also written for Cyclist magazine, edited the BikeMagic website and was founding editor of TotalWomensCycling.com before handing over to someone far more representative of the site's main audience.
He joined road.cc in 2013. He lives in Cambridge where the lack of hills is more than made up for by the headwinds.