Triple to Compact - shorten chain?

[Clydesdale]

I'm switching out the triple crankset that came on my cross for a compact and wondering if I'll need to shorten the chain a link or two? I'm running a long cage rear der. so I'm thinking no, but thought I would ask.

Thanks in advance.

[Mike748]

You don't need to but you might want to. How much smaller is the big chainring? Going from a 53 to a 50 you could take out 1 link (1" worth of chain). Probably not worth the hassle. I use the formula 2*(big ring + big cog)/4 + 2*(chainstay) +1 to figure chain length in inches.

[Pete Serotta]

The long cage might take up the slack...really depends on how "tight" chain was on triple and assumption that you are going from a 53 to a 50.

I would bet a beer that it will work as is though.


Could be a faster shift with the link out as Mike says

[Clydesdale]

I'll try it and see how it goes. My last cross bike had a compact and it worked well for what I ride. Now I hang out in the middle ring only, and I'm thinking i would like to go back. It might all come down to how much hassle it is getting the FD set and how the RD works with a double.

[RPS]

I'll try it and see how it goes. I think that's a good idea. Personally I would leave the chain length as is even if I could remove a link.

If the chain was previously cut correctly to handle the large-large combination (I’d confirm before taking it apart), by reducing from a 52T to a 50T big ring only shortens the chain requirement by ½ inch. It may be possible to remove up to 1-inch of chain depending on your bike’s specific chainstay length but why bother? It’s not like the triple’s rear derailleur doesn’t have more than the necessary capacity. And if your triple presently has a 50T big ring then shortening the chain may not be an option anyway (unless you are using a small-range cassette and therefore wasn't using the RD's full capacity).

Besides, after riding the compact for a while, you may miss that middle ring you ride all the time and may want to go back to the triple cranks. If so, the chain will be just right. ;)

[Dave]

I use the same 53 inch chain for a 50/34 compact or 53/39/28 triple with the same cassette.

Use the little/little method and make the chain as long as possible without hanging loose of rubbing on the RD cage.