Chainring change 42t to 40t

luv2ride

Thinking of changing my Sram Apex 1x chainset from 42t to 40t. Bike is also running an Apex 1x clutch RD. Will I need to shorten the chain, or is the clutch likely to take up any small amount of introduced slack?

N0bodyOfTheGoat

I think the general guideline is half the change, so one less link...

But having said that, I have 11-30 cassette on my Voodoo's 29er rear wheel and 11-34 on the fat rear wheel, even with a cheap rd310 rear mech I don't notice poor shifting with the 29er fitted.

whyamihere

It's nothing to do with the clutch, as long as you still have tension on the chain in the smallest cog, you're ok. It depends on how long the chain was originally. Pictures in the largest and smallest cog would help.

luv2ride

Yeah, I stupidly forget to check the chain tension with the 42t before the change. With the 40t fitted the chain feels ever so slightly slack, but not much. I was considering losing 1x link, but might run it first. If I dont get on with 40t / 11-42t and end up changing back, it would be good not to have to fit a new chain (#cheapskate)

janwal

I’ve done the same on my Trek Domane and the drop to 40 tooth worked just fine. All changes work without a problem.