Hello,

I have SRAM Red 2013 group installed just a week ago on a brand new frame. Bike has less than 100 miles. Cassette is 11-28T, chainring is compact, 30/54.

My problem is I can't shift into the 28T cog and small ring. I have verified:

- derailleur is not bent
- L limit screw is properly adjusted (I can shift to the 28T by holding the shifter lever, or by pulling the cable, but it won't stay there, as soon as I release it downshifts)
- All other gears work properly on both rings (no hesitation or difficulty in shifting)
- chain catcher on front is not rubbing against the chain when I manually shift to 28T.

I have tried adjusting the cable tension either way but no luck. What else can I try?