vtje

Hi, I have 2016 Specialized Roubaix which came with SCS wheels. Switched to non-SCS wheelset and replaced derailleur hanger. That all works fine, but I noticed that shifting is now a bit labored, not as crisp as it is on my other bike (same brand new 6800 Ultegra).
My thought is that my chainline changed by the SCS offset outward. Now, I have S-Works BB30 crankset on this frame, which I am not very familiar with. With Shimano, I would just add a 2.5mm shim on the right side to adjust my chainline, not sure if something like that possible with BB30? Thank you!

masont

It probably simply needs to be adjusted. The 2.5mm difference is real, but not enough to make it not shift well if it's properly set up.

No, you can't shim the crankset out.

cpach

It makes some difference, but I'll bet the difference in shift performance is more related to cable friction, derailleur setup, hanger alignment, chain condition, casette condition, and derailleur wear than chainline.

You cannot adjust the chainline on that crank/bb.

Andrew R Stewart 

So you replaced the cassette too, when getting the new wheels? Why didn't you just transfer over the current cassette? Did you also replace the chain so to start off with new cog teeth and chain links? Andy

vtje

Thanks, guys, it was a new build, so all the components were brand new.
Now, if it makes any sense, I noticed on my other bike that the cable is attached to the derailleur bolt outside, instead of inside the way I did it on this bike.
To my surprise, re-attaching it outside made all the difference.

trailangel

Had an Operator Error

Squeeze

Thanks for sharing this, and the picture. I learn a lot from posts like these.