First-gen SRAM Rival RD capacity?
 

Hello everyone,

I've got a bike I built up with mainly first-gen rival stuff (rd, brakes, and shifters). I'm planning on getting an 11-28 ultegra cassette. My question is, will the derailleur handle this cassette? I'm currently running a 12-25 shimano 105 cassette with a 105 compact crank and a 2011 Rival FD. This bike is intended for climbing "ridiculous" grades

I tried looking on SRAM's site but couldn't find the technical specifications for their components. I found installation manuals, but not specs. I've gotten an 11-28 to work on another bike with a 6600 short cage ultegra RD by adjusting the b-screw. But that bike has standard ultegra crank, so there's less of a tooth jump on the front rings.

Any guidance would be appreciated :)
neneboricua

I think Rival comes in either short-cage or medium. Short cage can handle 28T cog and 30T chain-wrap, whilst medium can handle 32T cog and 37T chain-wrap. Your suggested set-up (with 50-34 compact chainset) would have 33T chain-wrap so you need to have the medium cage according to specs. So if the grades are truly ridiculous you could even run an 11-32.