James wants to fit a larger sized triple chainset and he needs to know if he will need a longer chain. This is possible and there are a couple of other things he has to consider when he fits the bigger chainrings. These are our thoughts on what he should do.
Question: Presently I have a crankset that has chainring sizes of 48-38-28 but I would like to install a new crank that is bigger, 52-39-30 to be exact. I would like to know if I would have to get a longer chain???
The easy answer is that “yes” you will need a longer chain, but if the chain you have is quite long then the answer will be “no”.
You need to fit the chainset and then put the chain on the large chainring at the front and the largest cog at the back, this is not a gear you should use, but you need to test it. If it will go on them without over-stretching the rear derailleur then it should be OK. If not then you will have to add a couple of chain links or if the chain is old then fit a new chain.
The other things you will also have to consider are; will the front derailleur work on the bigger chainset? For a smaller chainring, the front derailleur is made for a smaller circle, but again it’s a case of trial and error.
The other thing to check is; will the rear derailleur take up the difference in the chain from 28 to 48 and 30 to the 52?
All things for you to try, it’s probable that the two derailleurs will be OK, but you may have to add a couple of links. Good luck.