cazdrvr
09-23-2007, 10:38 AM
I have tried searching here and in the Wrenching section and no luck. I had my Rival gruppo set up and working perfectly on another bike. Moved to a bike with braze on derailleur mount, which may not be the issue. Before I had the large ring set up with no rub and was able to trim the small front ring. Now I can't seem to get the same set-up without limiting the front derailleur from shifting from the small to big ring. I have followed the instructions on the SRAM site to the tee, or so I think. I thought I read somewhere that the height of the derailleur over the big ring teeth was important, not sure if higher vs lower was the trick. I have set it up both within a range of 1-3 mm per the instructions wit the same issue. Any tips, tricks, advice?
cx_fan
09-24-2007, 01:28 PM
The best way to set front der height is with a penny. If you can slide a penny horizontally between the bottom of the front der cage and the top of the chainrings, it is set at the correct height.
Now using a braze on ft der can be a bit more of a hassle. It might be out of spec a little, Maybe the curvature of the braze on is not correct, it was not welded on at the correct height, welded on at an angle. Very had to diagnose on a website though.
I have had great luck with having lot's of tension on the front der cable. The more the tension, the better it shifted. Also make sure that your limit screws are setup properly. Even if you are using the same cranks, it is a different frame and maybe the BB needs to be faced or you need to put in a spacer to get the chain line correct.
cazdrvr
09-24-2007, 03:19 PM
Thanks for the response! I will try the penny as a guide and work on the tension set up. So far, the frame has had 2 Centaur cranksets including the latest version with the Campy outboard bearings with no shifting problems at all. I honestly moved the SRAM stuff over to my Moots intending to sell the bike with the SRAM gruppo. The frame is a Colnago Master X Light without many miles. I did have to get the Italian bottom bracket bearings from SRAM for the swap.
stoopid question - for the chainline spacers - what is the optimal line up? Inner ring with the 5th cog down from the 23 or 5th cog up 11? I'm having a devil of a time with the FD lately and want to correct.
And I agree, the high cable tension works better for me too.