So I just got my new bike, a Cervelo S1.

Troulbe is, I need junior gears on it, but I'm not sure the FD will accomdate them. Its brazed on, so I'm not sure just how much vertical adjustment there is possible to be. It needs a 42t chainring as the largest one, while it now has a 50t.

Question is, will it fit?



joemmo [1164 posts] 5 years ago

The diameter of a 42t ring will be about mid way between the 50 and presumably the 34t inner ring if it's a compact chainset so have a look at how much adjustment you have to move it down on the bracket and estimate if you have enough. Or go to friendly local shop and see if they have a 42t ring you can measure against.