Originally Posted by
kcblair
Hello C&V Fans. This past winter, I upgraded my Ciocc. Added a 10 Speed 105 RD (med cage) and a 14-32T cassette. It's my fa. vorite climbing bike, but, I read somewhere here, if I adjust the B screw, I might be able to put on a 14-34. I have about 7 mm of adjustment , left on the B screw. I know I'll have to add to the chain. The FD is an early 105.
Thoughts ? Thank you all. KB
Edit :Total capacity for the 105 GS (5701 GS) is 37T. RD + 20 + FD 16 = 36. So that math adds up. My chainrings are 50/34T
While the only definitive answer will be to try it, I am currently using a 105-5700 RD on an 11-34 10-speed XT cassette, with 50-34 chainrings, 10-speed Dura-Ace downtube shifters. I think I have ridden this setup for about 600 miles with no problems.
I sized the chain to make sure the drivetrain can handle the big-big combo. My small-small combo may be a bit slack, but if so that's not a big problem as I wouldn't be using that gear on purpose anyway.
If your 105 RD won't play nice with the 34 tooth large cog, you can swap it out for an older Shimano 8-9-10 MTB derailleur like the Deore M591. That should plug right in and work with your 10-speed road shifting and easily handle the 34 cog.