Home » Bike Maintenance » Glossary: the language of bikes – page 2

Glossary: the language of bikes – page 2

  • Cup-and-cone bearings: These bearings roll around a cup on either side of the hub, trapped in place by a cone on either side. So that the wheel can turn freely with no side-to-side movement, set the distance between the cones by turning the cones so that they move along the axle threads.
  • Damping: Damping controls how fast a suspension unit reacts to a force.
  • Derailleur hanger: The rear derailleur bolts onto this part. This is usually the first casualty of a crash, bending when the rear derailleur hits the ground. Once bent it makes shifting sluggish. Luckily, hangers are quick and easy to replace, but there is no standard size; take your old one when you buy a new one, and get a spare for next time too.
  • Disc brake: This braking system uses a calliper, mounted next to the front or rear hub, that brakes on a rotor or disc bolted to the hub. Hydraulic versions are very powerful. Using a separate braking surface also means the rim isn‘t worn out with the brake pads.
  • Dish: Rims need to be adjusted to sit directly in the centreline of your frame, between the outer faces of the axle locknuts. Adding cassettes or discs to one side or other of the hub means the rim needs to be tensioned more on one side than the other to make room for the extra parts.
  • Dishing tool: This tool allows you to test the position of the rim relative to the end of the axle on either side of the hub.
  • DOT fluid: The fluid used in DOT hydraulic brakes. Higher numbers – i.e. 5.1 rather than 4.0 – have higher boiling temperatures.
  • Drivetrain: This is a collective name for all the transmission components: chain, derailleurs, shifters, cassette and chainset.
  • Drop bars: These curve forwards and downwards and are usually seen on road bikes. The brake-and gear-levers are combined into one unit for fast and instinctive shifting.
  • Duct tape: Like the Force, it has a dark side and a light side, and it holds together the fabric of the universe.
  • Dynamo bottle: A small generator that runs off the sidewall of your tyre, making electricity for your lights.
  • Elastomers: This simple spring medium is usually found only in cheap forks now.
  • End cap (cable end cap): This is crushed onto the ends of cables to prevent them from fraying and stabbing you when you adjust them.
  • End-stop screw: Used on derailleurs, this part limits the travel of the derailleurs, preventing them from dropping the chain off either side of the cassette or chainset.
  • Eye bolt: On cantilever brakes, the stud of the brake block passes through the eye of the bolt. Tightening the nut on the back of the bolt wedges the stud against a curved washer, holding the brake block firmly in place.
  • Ferrule: This protective end cap for outer casing supports it where it fits into barrel-adjusters or cable stops.
  • Fixed wheel: Without a ratcheting mechanism in the back wheel, the pedals must keep turning with the back wheel. Beloved of cycle messengers, they allow you to control the speed of your back wheel precisely.
  • Freehub: This ratcheting mechanism allows the back wheel to freewheel when you stop pedalling. It‘s bolted to the back wheel, and has splines onto which the cassette slides. This is the part that makes the evocative ‘tick tick tick‘ as you cycle along.
  • Freewheel: This older version of the sprocket cluster on the back wheel combines the sprockets and ratcheting mechanism in one unit. Freewheels are rarely used for multispeed bikes now; the cassette/freehub set-up is far stronger, as it supports the bearings nearer the ends of the axle. Freewheels are often found on singlespeed bikes.
  • Front derailleur: This part moves the chain between the chainrings on your chainset.
  • Gear ratio: Calculated by dividing chainring size by sprocket size and multiplying by wheel size in inches, the gear ratio determines the number of times your back wheel turns with one revolution of the pedal.
  • Guide jockey: The upper of the two jockey wheels on the rear derailleur, this part does the actual derailing, guiding the chain from one sprocket to the next as the derailleur cage moves across beneath the cassette.
  • Hop: This term describes a section of the rim where the spokes don‘t have enough tension and bulge out further from the hub than the rest of the rim.
  • Hub gears: Also known as internal gears, these have a single sprocket and chainring, with three, four, seven, eight, 11 or 14 gears concealed within the rear hub. The added bulk of the rear hub means they’re affectionately known as ‘tin can gears’.
  • Hydraulic brakes: Usually disc brakes, these use hydraulic fluid to push pistons inside the brake calliper against a rotor on the hub. Because brake fluid compresses little under pressure, all movement at the brake lever is accurately transmitted to the calliper.
  • Indexing: The process of setting up the tension in gear cables so that the shifter click moves the chain across neatly to the next sprocket or chainring.
  • Instruction manuals: Often ignored or junked, these contain vital information. Keep them and refer to them!
  • International Standard: This term refers to both rotor fitting and calliper fitting. International Standard rotors and hubs have six bolts. International Standard callipers are fixed to the bike with bolts that point across the frame, not along it.
  • ISIS: This is a standard for bottom brackets and chainsets and has 10 evenly spaced splines.
  • Jockey wheel: These small black-toothed wheels route the chain around the derailleur.
  • Lacing: This technique is used to weave spokes to connect the hub to the rim. This part of wheelbuilding looks difficult, but it is easy once you know how.
  • Link wire: Used in cantilever brakes, this connects the pair of brake shoes to the brake cable. It is designed to be failsafe; if the brake cable snaps, the link wire falls off harmlessly rather than jamming in the tyre knobbles and locking your wheel. You are still left with no brake though . . .
  • Lockring: Used on bottom brackets and barrel-adjusters, this is turned to wedge against frame or brake lever to stop the adjustment you‘ve made from rattling loose.
  • Lower legs: The lower parts of suspension forks, these attach to brake and wheel.
  • Mineral oil: This hydraulic brake fluid is similar to DOT fluid and must only be used with systems designed for mineral oil. It is greener than DOT, and less corrosive.
  • Modulation: This is the ratio between brake lever movement and brake pad movement, or how your brake actually feels.
  • Needle bearing: Similar to a ball bearing, a needle bearing is in the shape of a thin rod rather than a ball. Since there is more contact area between bearing and bearing surface than with the ball type, they are supposed to last longer, but they can be tricky to adjust. They are usually found in headsets, although some very nice bottom brackets also use needle bearings.
  • Nest: This hanger or stop in a brake lever or gear shifter holds the nipple on the end of the brake or gear cable.
  • Nipple: (1) This blob of metal at the end of a cable stops it slipping through the nest; (2) This nut on the end of a spoke secures it to the rim and allows you to adjust the spoke tension; (3) This perfectly ordinary part of a bicycle causes the pimply youth in the bike shop to blush furiously when asked for it by women.
  • Noodle: This short metal tube guides the end of brake cable into V-brake hanger.
  • Octalink: This is the name of the Shimano eight-splined bottom bracket/chainset fitting.
  • One-key release: The combination of axle bolt and special washer fits permanently to the bike and doubles as a crank extractor.
  • Overshoes: Nylon or Gore-Tex bootees that fit over your cycling shoes to keep the weather out. They’re quite bulky, so you feel slightly foolish in them, but it’s better than feeling stylish with cold feet.
  • Pannier: A bag or bags that sit either side of your rack.
  • Pawl: This part allows you to freewheel: a sprung lever inside ratcheting mechanism in the rear hub is flicked out of the way when the ratchet moves one way, and catches on the ratchet teeth the other way.
  • Pinch bolt: In this version of a clamp bolt, the cable passes through a hole in the middle of the bolt, rather than under a washer beside the bolt. Occasionally it is found on cantilever straddle hangers.
  • Pinch puncture: This happens when the tyre hits an edge hard enough to squash the tube on the tyre or rim and puncture it. It is also known as snakebite flat because it makes two neat vertical holes a rim width apart. Apparently this is what a snake bite looks like, although we’ve never had a problem with snakes biting our inner tubes.

Source : BIKE MAINTENANCE TIPS, TRICKS & TECHNIQUES

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