*Most chain problems are the result of dirt, chain wear, or stiff (frozen)links. DIRT can mix with the oil on your chain and cause accelerated wear on the chain, cogs, chainring, and derailleur pulleys. Dirt trapped between the chain links and pins can cause difficulty in shifting and reduce the chain's flexibility. CHAIN WEAR or "chain stretching" can cause excessive noise while riding, and slow down shifting and make proper index shifting difficult. A worn chain is usually OK as long as the sprockets it is on wear at the same rate. Often when you replace a worn chain, you find you may also need to replace the chainring and/or rear cassette as well, as they no longer mesh together properly. This can cause "chain skip" where the links no longer fit the teeth due to wear, and is made evident when the chain lurches in your pedal stroke and jumps forward and "skips teeth". You can measure the chain with a measuring gauge to check for wear and stretching, or carefully inspect the sideplates for bulges or flared edges. With normal use, a chain should last a few years. STIFF LINKS can also cause the bike to skip. A tight link can be felt while guiding the chain thru a hand held rag after lubrication, or sometimes is visible upon inspection. You can also spot a bad link by turning the crankset backwards and locking at the jockey wheels on the rear derailleur. A tight link will not lie snugly on the pulley's as it passes over them. It is noticeable by a repetitive "skip" in the chain on each pedal stroke. This condition results when the link is too tight to flex properly over the chainrings, and thru the derailleur. Once identified, you can attempt to "free up" the offending link by cleaning, lubing the area, manipulating the link with your hand, or sometimes using the chain tool to move the pin a slight amount. If this doesn't work, you may need a new chain, and possibly more (see above)... CHAINSUCK is a condition that occurs when the chain gets sucked up and jammed between the small chainring and chainstay. Usually it occurs when shifting onto the small chainring, and when it happens, it jams the pedals, and forces you to stop. To prevent chainsuck, keep the chain clean and well lubed. Sometimes muddy conditions, or a worn chain or chainring can cause it. In effect, the chain gets stuck on the chainring too long to cause this problem, and doesn't want to come off. If it happens, stop pedaling - you will have to - and correct it, or it may permanently damage your cassette or chain, and is quite aggravating. |
