Cyclocross - Soma Double Cross Build Question

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Dr. DRE
01-03-08, 07:52 PM
Hi All,

I'm gathering the parts to build up a Soma Double Cross, and here's what I'm thinking for the drivetrain, and I'd like your thoughts/warnings!

Crank: Ultegra road (6600) 39/53
FD: Dura-Ace FD-7700 (9 sp)
RD: XT M760 GS medium cage
Cassette: SRAM PG-950 11-28 (yes, I'm skimping here)
Shifters: Dura-Ace 9-speed bar ends

There doesn't seem to be any reason why the shifters shouldn't work with the XT derailleur, but I got them today and the instructions say ONLY use a Dura-Ace RD. I think this is just to sell more Dura-Ace parts--am I right?

Finally, the XT medium cage RD is rated for 33 teeth--technically, that means I should be able to use an 11-32 cassette if it can handle going 2 teeth over. What does anyone think? I read here that the ratings are conservative, so I maybe can get away with it. I could also, of course, just buy a long-cage RD, but I've got this one already.

The bike isn't to race--it's for all-purpose road'n'trail riding. That's why no compact or 'cross crank. The 39/32 or even the 39/28 ratio should be fine for any climbing I need to do.

Thanks for your advice!

matthew_deaner
01-03-08, 08:23 PM
I have the same setup (9-speed dura ace bar ends and med-cage XT rear der) and it shifts without a hitch. If you have the rapid-rise version, you might have to get used to shifting the opposite direction though... Right now, I have one bike with a regular derauiller and bar ends, and two with rapid rise, and it's difficult to transition between them.
cachehiker
01-04-08, 10:49 AM
I have similar setups on my Soma Double Cross and Jamis Aurora. Unless you're a serious pedal masher, the 53-11 gear will get so little use on a non-road race bike that I'd eventually swap the 53 for a 48 or 50. The RD should work fine with an 11-32 cassette unless you're in the habit of constantly cross chaining. Two teeth over on maximum capacity I will do but I'm a little hesitant to go four teeth over. Just make sure the chain is left long enough.

Dr. DRE
01-04-08, 03:17 PM
Thanks Matthew and cachehiker. I feel reassured and more confident. Cache, I agree with you on the 53t gear--One thing would be that switching to a 48 or 50 would make it a no-brainer to go to an 11-34 cassette, which would give a better range. I'll look into it.

Thanks again for the words of wisdom!