[2piece]

...If so, what brand/type/size on your DH bike. Your opinions would be appreciated

 

[Toshi]

i had a sram r9. 11-25? something like that. worked fine with an ultegra rear mech, smooth shifting. i switched to a 11-34 cassette for the 36x34t "climbing gear" that i get as a result.

 

[biker3]

a shimano ultegra 12-27 in the rear with a sram x.o rear mech. It works great and the shifting is soo buttery every time.

 

[RD]

Ultegra 12-27 on 3 different bikes, Hardtail, DH, and Slalom. All with Dura-Ace rr mech's and SRAM Rocket trigger shifters. Great shifting

 

[Slacker]

Ultegra 12-23 (i think) with Ultegra der... super smooth shifting here too

 

[Acadian]

SRAM 12-26
X.9 or X.0 Derailleur
works dandy!

 

[Shmoe]

Ive done it before, seemed to loose any benifits when not using a road derailleur, because if you used a regular rear D you need a longer chain and your not gaining any clearance. I prefer my x.7 set-up with a 11-32 cogset for the riding that I do. I have found that the road derailleurs are very very weak (what do you expect?).

All in all, do what you want but make sure you ran a x7/x9/x0 rear D and shifter..

 

[Rik]

seemed to loose any benifits when not using a road derailleur

A tighter range with closer ratios also has a benefit of smoother acceleration due to a smaller jump between gears.

 

[J5ive]

Running an ultregra 12-21 at the moment. Will change to a 23 or 25 though. I like it. Combined with a 38/40 and I get a good range.

 

[2piece]

Thanks for all the great responses.

 

[Andy_B]

Ultegra 12-23 on the MTX Bike and a Crappy Ulterga Mech...it dose not shift for crap
Sram r9 12-26 on the DH Bike w/ X9 mechs sooooo smoooth