Chain length?



Alan O'Brien

New Member
Feb 9, 2017
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Hi guys, just wondering if you could help. I'm building a bike bit by bit and what the best length of chain to put on it. Basically, I'm building a 2012 giant TCR advanced, with a 10 speed ultegra group. I'll be running a 53x39 chainset with 11-25 cassette. Thanks in advance, Alan.
 
To have any chance of being able to tell you which chain length to use, one would have to know your chainstay length.
There are chain length calculators for fixies etc. don’t know if there are any for derailer gear bikes.
Anyhow, measuring the frame close enough to calculate chain length takes more effort than fitting a chain to the bike.
And since chains are generally sold over-long, you have to buy a chain breaker anyhow.
So you might as well invest some time in doing a net search on ”chain length sizing” and learn to do it yourself.
Compared to the overall difficulty of building a bike, chain length sizing isn’t much to worry about.
 
ALSO ...

The length of the rear derailleur's cage may-or-may-not be a factor to consider ...

When I have the option (and, it is usually mine to make), MY preference is for a longer cage & a few extra chain links.



 
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ALSO ...

The length of the rear derailleur's cage may-or-may-not be a factor to consider ...​


Depends on which chain sizing method you use.
Derailer cage length doesn’t matter if you use the big-big method.
But if you do small-small a longer cage will let you run a longer chain.​
 
Before sizing the chain length, you must know the distinct types of chains.There are two types of a bicycle chain. The special connecting rivet chains and master link which are used in chains. In a master link chain, it uses two outer plates connecting the chain that can be taken off. Rivets are used to connect a rivet chain.
Take off the chain and check its size. You must confirm the accurate length before attempting to remove it. Into the biggest rear cog and chainring, you must shift the bike. The chain must be in a long size to do the shift with two slight bend at each pulley of the rear derailleur.
 
Wow, I'm not really aware about the length of my chain. All I know is to use my bike, and if I need to buy some parts, I will simply bring my bike and show the part that I need to buy and they will give it to me. I wonder if the chain will effect the performance of the bike? specially the length of the chain?