Originally Posted by
shapelike
Okayguyses, let's have bike talk!
FSA Gossamer compact crank (50/36). It's billed as being 9/10 speed compatible, but in reality in the small ring my last 3 gears are unusable due to the chain rubbing (and at times catching) the big ring next to it. The 9sp chain is slightly too wide to clear the ring next to it. The rest of my drivechain is all 9sp (105 shifters/front derailleur, deore rear derailleur, hg50 cassette) and I can't afford to change that. Soo ... ideas are to try to use some chainring spacers to move the small ring inboard .5mm and see if that helps, or reduce the chain to the minimum length and see if that helps free up things a bit too. The concern is that if I move the chainring inboard too much the chain will drop between the gap and removing links still won't make the whole range available in the back.
Taking a look at where the chain actually rubs/catches ... *looking* ... I'm also thinking this problem might be solved by going down to a smaller big ring. I could use one anyway, but this might just mean the chain rubs on the teeth vs. just below them.
Meh, ideas? I'm off to practice and pick up some spacers at Fur Brain.
I would space the big ring further outboard rather than small ring inboard. Did the crank/BB come with any spacers for the BB? Manipulation of the BB spacers...like putting an extra .5 on the drive side of the BB might help as well. If you want to get a perfect set-up for cross maybe take the big ring off all together. I have an old 110 modified chainring that I used as a bash guard/ring keeper...you can use it if you like...and put a cateye keeper on the inside. I know you ride this on the street as well but in a cross race there is little likelyhood of even needing the big ring.