mx_599

have any of you tried to use SRAM road (rival/force) derailleurs off road?

the ratio pull isn't explicitly stated anywhere (that i quickly found...) and i suspect SRAM altered something so people wouldn't do this...?

however, have any of you tried to see if the ratio was close enough that it wouldn't matter?

i guess there might be a problem with clearance on the larger cassettes of mtb's...but maybe not...still offers some interesting possibilities

how about the front derailleur at least? seems more likely this would work....no? since lots of people use an xtr front, has anyone looked at the road fronts instead for there mtb?

thanks

JiveTurkey

For Shimano, the FDs between road and MTB are not compatible (different cable pull ratios). Since SRAM road FD & Shimano road FD are compatible and SRAM MTB FD & Shimano MTB FD are compatible, that leads me to believe SRAM road FDs won't work with MTB shifters.

SRAM road RDs use the same 1:1 ("exact actuation") cable pull ratio as SRAM MTB RDs, so they are interchangeable. But you should look out for max cog and total capacity.

blamp28

Are you sure that SRAM Road rear ders are 1:1? That's great because I have a project in mind. As far as SRAM off road rear ders. go, some are 1:1 and some are 2:1 to be compatible with Shimano drive trains. X.7, X.9 X.0 are all 1:1 as are their shifters. most others are 2:1 as are their shifters. If indeed the SRAM road ders are 1:1, you would have to mate them with one of the 1:1 shifters. The SRAM off road rear der is the most robust I have used. Why would you substitute a road der for that? What advantage would there be? I'm just curious. Those X.9s are just about bulletproof.

mulzi

the SRAM dealer in Australia says that sram high end mtb and road components are not compatible. I was specifically after using a force rear mech with a X.0 trigger shifter but was told that it is not compatible. Straight from the dealers mouth

mx_599

i didn't quite follow that but it might be because i am half asleep. did you have a typo in there?

did you read the the sram road is 1:1? hmmmm

blamp28

I have also heard that they are not compatible but I would like to know for sure. I want to put the Rival or Force group on my tandem but will need to use a MTB rear derailleur due to the climbing ratios needed for the tandem. This would mean using a SRAM X.9 but I cant find out if it will work with the Rival shifters.

maddmaxx 

SRAM road is not compatable with SRAM MTB.

SRAM road FD is not compatable with Shimano

SRAM road shifters and both front and rear derailleurs are specific to SRAM road only.

SRAM road cassettes and chains are interchangeable with Shimano 10 sp.

SRAM MTB cassettes and chains are interchangeable with Shimano 9 sp.

mx_599

yes, i am only concerned with the 1:1 "high end" stuff.

the goal would be to use xo twist shifters with one of these road derailleurs.

weight and price. compare force vs xo RDs. i am aware of jockey wheel "arm" length and larger cassettes... however, i was thinking it might still work if you do not use the largest cog and a 2 chain ring set-up. i am thinking it would be similar to the short arm lengths or off-road derailleurs.

i am also fully aware of durability issues...but i suspect that the road ones would hold their own quite nicely. furthermore, i have gone years without breaking a RD. maybe luck, maybe because i don't ride as much as others, etc...but that is besides the point.

mx_599

likewise...but have you tried? just because a rep says you can't, doesn't mean you really can't.

mx_599

yes, but have you tried any of the above? ....but what is the pull ratio? it must be close to 1:1

i am almost thinking that a sram FD would work because there is a little "less" precision with FD. i just eyed up the road FD and i thought they looked pretty nice to the sram mtb x9.

maddmaxx 

derailleurs get "SRAM Exact Actuation," which is not quite the one-to-one actuation ratio of SRAM mountain derailleurs, so Force and Rival shifters are not compatible with SRAM X.0 rear derailleurs.

The above copied from Zinn's review of the system for Velo News.

mx_599

i read that too....awhile back. oh well, thanks everyone.

i will probably still try

mtnbiker4791

I went to the Sram university tech clininc a bout a month and a half ago and the road and mtn sram derailuers will not work with each other as the are a different actuation ratio. Sram road is a true 1:1 ratio hence the exact actuation moniker and the mtn varies off of 1:1 depending on where the der is in its travel. If you do try it it might be close but wont shift perfectly

JiveTurkey

Edit: Scratch that, I thought SRAM road FDs and Shimano road FDs were compatible, apparently not, according to maddmaxx.


Sorry, I just read that SRAM road RDs used "exact actuation" and I thought that meant 1:1. Apparently, it does, but the MTB "1:1" is not really 1:1. Wow.

Owner

Did you end up trying this? I'm trying to figure out if there's any long cage RD I can use with a Force brifter.

Dan Burkhart 

Which STU session were you at?

Wordbiker

If you've attended STU then you'll also note that the geometry of the derailleur is completely different between road and mountain due to the angle that the derailleur follows with wide-ratio versus close-ratio cassettes.


Given that, it's understandable why cable pull would differ slightly.

Owner

So does that mean there's no way to use a long cage RD with a Force shifter? I was hoping to run a 11-34 cassette for the Death Ride.

mx_599

i am sorry, i have not. i guess i posted this way in advance of my build