Chain Life
- Thread starter oldrnyzr
- Start date
Some chain mfg's will recommend you change out the chain when it has reached ~1.5% (non-ring chain) and 1% (ring chain). However, you can probably keep the chains in service until they reach a point of ~2-2.5% over original pitch length.
The reason they state a .5 variance between a ring chain and a standard non-ring chain is that once a standard chain gets close to the bench mark, you can still lubricate it and get some good hours out of the chain. A ring chain on the other hand cannot have the critical friction points relubed, and it will be on a very fast downhill slide.
Keep in mind that the longer you run the chain, the more chance there is of it wearing at the sprocket teeth.
If you decide to subscribe to changing them out at the 1.5% over original pitch mark, you can probably keep the original sprockets on through possibly several chain changes.
If you run longer, to say the 2.5% or over mark, you will more than likely see at least a bit of tooth damage, and should change the sprockets out as well.
Super hard steel rear sprockets fight the degredation from a chain that is too long, and will often times fool you into thinking things are OK with the chain, when in fact it has elongated past recommended specs. and could actually be dangerous to ride with.
When meausring, always measure a number of links, as it is a bit tough to get a precision measure of just one pitch. Also check several sections of the chain, as there could be one or more worse sections than others.
The most accurate way to measure for pitch length is to use a dial caliper.
With the chain taught, measure from outside to outside of the rollers of say 9 links and write that measurement down. Then measure from the other side of the same roller to the other side of the other roller, and also write that down. Add the two measurments together then divide the number by 2. This will be the exact pitch length of that section of chain.
A 520 chain has a pitch of .625", so 9 links should measure exactly 5.625" when new.
When that section measures 5.74" it has elongated 2% past new pitch length.
The reason they state a .5 variance between a ring chain and a standard non-ring chain is that once a standard chain gets close to the bench mark, you can still lubricate it and get some good hours out of the chain. A ring chain on the other hand cannot have the critical friction points relubed, and it will be on a very fast downhill slide.
Keep in mind that the longer you run the chain, the more chance there is of it wearing at the sprocket teeth.
If you decide to subscribe to changing them out at the 1.5% over original pitch mark, you can probably keep the original sprockets on through possibly several chain changes.
If you run longer, to say the 2.5% or over mark, you will more than likely see at least a bit of tooth damage, and should change the sprockets out as well.
Super hard steel rear sprockets fight the degredation from a chain that is too long, and will often times fool you into thinking things are OK with the chain, when in fact it has elongated past recommended specs. and could actually be dangerous to ride with.
When meausring, always measure a number of links, as it is a bit tough to get a precision measure of just one pitch. Also check several sections of the chain, as there could be one or more worse sections than others.
The most accurate way to measure for pitch length is to use a dial caliper.
With the chain taught, measure from outside to outside of the rollers of say 9 links and write that measurement down. Then measure from the other side of the same roller to the other side of the other roller, and also write that down. Add the two measurments together then divide the number by 2. This will be the exact pitch length of that section of chain.
A 520 chain has a pitch of .625", so 9 links should measure exactly 5.625" when new.
When that section measures 5.74" it has elongated 2% past new pitch length.
