BICYCLE CHAIN MAINTENANCE
INTRODUCTION
Chain maintenance is one of the most simple and effective maintenance tasks you can perform on your bike. A few minutes spent on your chain will mean longer chain life, smoother gear shifting, and generally a more pleasurable riding experience.
CLEANING
The golden rule is never be tempted to lubricate a dirty chain as this only serves to drive dirt into the chain and therefore shorten it's life. The secret to avoiding having to use solvents or chain cleaning units is simply to wipe the chain clean with a rag at the end of every ride, it takes 60 seconds max and it keeps your chain in really good condition. It's also a good idea to wipe any dirt off the rear cassette, jockey wheels and front sprockets - then its ready for lubing.
If your chain is really dirty, through neglect or very dirty conditions, it's best to invest in a chain cleaning bath as this avoids taking the chain off the bike. Use only a citrus-based degreaser not petrol or kerosene, as these will tend to drive oil out of the rollers and dry the chain out. Once cleaned, wipe off thoroughly with a clean rag.
LUBING
There are different lubes for dry and wet conditions. Wet lubes are thick and sticky to avoid being washed off (great for wet, winter riding or mountain biking), dry lubes are thin and light to avoid picking up dirt (more suitable for shorter, dry rides). Now because I clean and lube after every ride I use a very light oil (I actually use sewing machine oil) and I find it's great for not picking up too much dirt and makes cleaning at the end of a ride very easy.
Put one drop of oil on each roller as you slowly rotate the chain remembering to drop the oil onto the inside face of the chain - as this is the cleanest side and will help stop the oil dragging dirt into the rollers. Once lubed wipe off any excess oil with a clean rag. If you're a bit of a perfectionist like me you can leave it for a few hours (or overnight) to allow any excess oil to come to thesurface then lightly wipe the chain again.
CHECKING FOR WEAR
Chain life can range dramatically from under 1000 miles in a worst case scenario to over 5000 if cleaned and lubed regularly, and ridden in dry conditions. So how do you know when it's worn out? Wear on the rollers and links will cause the chain to stretch as it wears. When the links have stretched too far they will not fit the sprockets properly and will cause gear shifting problems.
The simplest way to check is to use a chain elongation gauge, they are relatively inexpensive, freely available and easy to use. Alternatively you can simply measure the chain, each link should be one inch long so 12 links should be exactly 12 inches long. To check this make sure the chain is tight and measure from the centre of one chain pin to the centre of the chain pin 12 links away. If the stretch is 1/16 of an inch or less the chain is still fine, if its between 1/16th and 1/8th the chain needs replacing. If its stretched 1/8th or more then its likely that the rear cassette and front chain-rings are worn as well.
Remember, not changing your chain when it has become worn is a false economy, as a worn chain will rapidly accelerate wear on the front sprockets and rear cassette, which cost a lot more to replace than a chain!
REMOVAL
Because of the high stresses that modern chains have to endure it's a good idea not to remove the chain unless you really have to or, of course, if you are replacing it. This is because every time you drive a pin through a link it will slightly stretch the link hole and thus weaken the link. If you do want to remove and replace an existing chain its best to get a SRAM master link as this will allow you to safely remove and replace the chain as often as you like.
To remove a chain you will need a good quality chain removal tool. Place the chain tool on the chain (making sure the driving rod is centered exactly in line with the link pin, then tighten the chain tool until it will go no further - this will drive the link pin out of the chain. Depending on the type of chain tool you are using it should leave the pin in the chain but will leave enough gap for the links to come apart.
REPLACEMENT
If you are replacing with a new chain you can check the correct length by just checking against the old one. If you want to double check you can do this by wrapping the chain around the big chain-ring and the biggest rear cog whilst bypassing the derailleur completely – when pulled tight the chain should overlap by 1-2 full links. If it is too long just remove the appropriate number of links with the chain tool.
When fitting the new chain make your life easier by not having it on the chain-rings, as this will stop you fighting the spring of the derailleur. Drop the chain onto the smallest cog then thread the chain back over the top of the top jockey wheel – making sure you thread it through the rear cage guide pin. Take the new connecting pin (supplied with the chain), drop a little light oil on it and then push the beveled or tapered end into the link hole first. Using your chain tool, drive the pin in up until it protrudes as much as the others. It will feel hard at first then it will suddenly go very easy, then hard again. Make sure you don’t push it through too far. Its best to check and then go a little further. Finally check the link to make sure it is free and easy. You shouldn’t have to stretch the chain sideways to make it free.