The bicycle chain has the nasty habit of breaking down at the most inconvenient of places and times. However, most of the problems of a jumpy or jerky can be avoided if the chain maintenance is proper. Ideally, the chain needs to be checked twice a month or after about 10 hours of riding time. It is also important to check the chain after riding in the rain or bad weather.
Generally, the chain should be replaced if it is worn out, tight, rusted or has run more than 1000 miles. The length of a new chain with 24 links is 12 inches. If the length exceeds by 1/16 of an inch, the chain should be replaced to avoid damage to the sprocket and chain ring. Also, if you are replacing the sprocket and chain rings, you should replace the chain at the same time to prevent damage to the new parts.
While the metal parts do not actually stretch, the chain gets longer due to wear and tear of pins and sleeves. Keeping the chain lubricated is the best way to prolong its life. For best results, a drop of lubricant should be put into each and every pin in the chain. While other methods may be faster or less messy, they are not as good in lubricating the entire chain.
After soaking the chain for 15-20 minutes, it should be wiped dry with a clean rag. This stops the chain from attracting dirt while riding. It also slows down the expansion of chain due to wear and tear.
A dish soap or a de-greaser can be used to clean the chain by removing grease, grime and lubricant. Always lubricate the chain after cleaning it. For cleaning the chain, the cleanser should be placed in the center of a sponge or rag. It should then be placed around the chain and backpedaled. This procedure should be repeated by rinsing the rag every time until the chain is free of dirt.
Remember to leave the chain on while cleaning to prevent it from getting weakened. While cleaning the chain, it has to be inspected for any tight links by backpedaling and watching the chain in the rear derailleur. A tight chain can jump the teeth and may have jerky movement. When the tight link is identified, it can be loosened by flexing between two points five links away on either side of the tight link. If it does not get loosened, replace the chain. Keeping the chain clean and lubricated will also prolong the life of the pins and sleeves/bushes of the chain.
When the chain is noisy on a ride and cleaning does not help, it needs to be replaced. Also, when the pedaling becomes rough and sprocket teeth are not fitting properly to the chain, it is time to change the chain.