Adjusting gears and maintaining chain
Below you'll find information on different gear systems including how to adjust your gears, plus info on cleaning and oiling your chain to ensure your bike keeps running smoothly.
Different gear systems
Most gear systems on bikes are derailleur. Some bikes have hub gears; however as these are comparably uncommon in the UK and need less maintenance than derailleur systems they are not covered on here.
Derailleur gears use a combination of different sized front and rear chain rings with a chain that can be moved between them so that different pedalling force is required to drive the back wheel.
Most modern gear systems will be indexed; this means that you will move the gear lever one click and the chain will shift exactly onto the next chain ring. On some older systems, there is no click: you have to teach yourself how far to move the lever to get an accurate gear change.
You may notice that over time your gears go out of alignment, so that as you cycle you are unable to change gears smoothly, the gears jump or the chain falls off. These problems can occur as your gear cables stretch with time, the chain, cogs and sprockets wear or if the gear mechanism gets bumped.
Adjusting your gears
If the gears are not changing smoothly you may only need to make a small adjustment. If you have indexed gears you will be able to do this by turning the barrel adjuster by the gear levers or at the derailleur.
You can adjust the movement of the derailleur mechanism to prevent the chain going beyond the cogs, by two small stop screws on the mechanism (usually marked H and L). They should allow the chain to move up and down the cogs without coming off the top or bottom.
Cleaning and oiling your chain
You should clean your chain before you lubricate it; you can use degreaser or special cleaning product from your bike shop.
There are special chain cleaners on the market which fit over your chain, or you can run your chain through a rag coated in cleaning material, until no more dirt comes off. To get your chain really clean you should clean every link individually.
You should then clean the chain rings at the front, the sprockets at the back, jockey wheels and all other related parts.
Once these are all clean you will need to oil the chain and exposed metal parts. Oil the inside of the chain, running it around the chain wheel and sprockets a couple of times as you go; leave it to penetrate for several minutes, then wipe off the excess. Excess oil or grease on the outside will attract dirt; this will wear out the chain.
It is best to use a light oil like 3-in-One or you can also get specialist lubes from bike shops designed for the different conditions you may ride in.
MadeGood.org have a section on chain care:
Included in their tutorial is how to lubricate your chain, measure chain wear, put a new chain on your bike and how to connect and break a chain. MadeGood provide one of the best bicycle repair libraries on the web, and is totally free to access. You can also follow MadeGood on twitter - @MadeGoodBikes