Right, this makes sense by my logic, but i'm keen to find out if it's actually right or not before i buy a new mech.

If i run a Sram Rival STi which apparently has a constant cable pull of 3mm (and is designed for a 1:1 ration rear mech) with a 1:1 ratio X.9 rear mech and a standard 10sp road cassette, will it work?

Scottish mud and my Rival rear mech on my cross bike are somewhat disagreeing, so this may be a solution. Opinions would be greatly appreciated.

Ta, Pete

Not helpful and slightly off topic but is there a website that tells you this stuff?

Cable pull, ratio etc.

Not just for Sram stuff but all brands.

i think that the jockey wheels will be too fat for a 10 spd chain, although you could possibly swap them if the width at the bearing is the same

well, being the impatient man that i am, i just went and nicked the derailleur off my MTB…to answer my own question, it does indeed work. However, the cage is a bit long and there's no adjuster so you have to be very very precise setting the cable tension in the first place. Jockey wheels do look a tad fat i'll agree but they hold the chain nicely. I'll go for a ride later and see how i get on. I guess if needs be, i could swap in the jockey wheels from the Rival mech – though i'll need to check they have the same diameter bolt-hole.

@ ctznsmith, not sure to be honest. I just know that SRAM's road stuff is a standard 3mm pull for every change and it says on their website it's 1:1. I only found out today that the MTB mechs were 1:1 pull when i looked on the chainreaction website.

<insert standard thread resurrection comment here>

Anyone else tried anything similar – I’d like to go for a 1×10 set up on my CX bike but with an 11-36 cassette which a road rear mech won’t take – eg I’d want to use a mtb mech.

Yes, in general MTB mechs work fine (not sure about the latest shimamno MTB 10 speed though, which might have a variable pull ration through the cassette range??)

Just used an old 9 speed MTB one with 10 speed shimano STI and 10 speed cassette. have to set it up close to the cassette with the B-limit screw thing.

Yeah, shimano (other than the new 10 speed mtb stuff) is all cross compatible but I have heard other people say that the SRAM road/mtb stuff isn’t and I want to use SRAM on this.

SRAM 10 speed stuff is the same road and MTB, but 9 speed isn’t. So you can use a 10 speed SRAM MTB mech with SRAM Double Tap levers.

On Shimano stuff you can use a 9 speed mech (only Shadow ones will manage a 36t though), with all 10 speed STIs except 5700, 6700 and 7900. Those groups will work with all 10 speed Shimano mechs.

Thanks Njee – that’s good to hear.

So, actually what I want to try is Campag ergo shifters with an X9 10 speed rear mech and a 10 speed cassette…

(based on this thread that suggests Campag and SRAM shifters are cross compatible)

There were rumours of an Extra-Short cage X0 mech intended for cross use with road shifters, but I’ve not seen anything about this since last year.

Those groups will work with all 10 speed Shimano mechs.

To ask a thick question, is that including 2011 SLX/XT/XTR?

So, actually what I want to try is Campag ergo shifters with an X9 10 speed rear mech and a 10 speed cassette…

Pity the rumoured Fulcrum MTB group has yet to see the light of day…

Andy

My understanding was that since 9 speed mtb rear mechs apparently don’t work with the 10 speed mtb shifters but do work with 10 speed road shifters (clear?) that the 10 speed mtb rear mechs aren’t compatible with 10 speed road shifters. Happy to be corrected though…

Pete, the OP kindly replied to an email I sent him:

Yes, I did have a play around with using SRAM STi’s with a MTB (X.9) rear mech on my cross bike last year.

Initially it seemed pretty good, but after actually getting out and riding a bit, it turned out that the cable pull wasn’t quite right for the mech; it would get out of sync with the cogs in the middle of the cassette, match up again with 7,8 and 9, and wouldn’t reach to 10 (or wouldn’t get down to 1 – depending on which cog it was centered to) Does that make sense?

There was no doubt though (in my mind), that the shifting performance was far better in the mud, the cables didn’t clog nearly as quickly, and I could reliably make it to the end of each race with exactly the same shifting – which was fantastic. But it was always a bit patchy in the middle of the cassette, which wasn’t really ideal, and would lead to clicking and missed changes etc.

So, when I saw that SRAM were introducing 10speed MTB rear mechs at the end of last year, I got one of those. As you’d expect, being designed for the same 1:1 (3mm) cable pull, it does the job perfectly, with the benefits of both. Sorted!

Now I can’t really vouch at all for the campag idea as i’ve never even thought about it; all my bikes run SRAM these days. Definitely trying the new 10speed SRAM mechs with Campag Ergos won’t be up to much as it’ll be exactly the same as trying to use a campag shifter with SRAM road mechs – I.e. youill need a shiftmate to make it work.

With the 9sp MTB mechs though, I don’t know. That CTC article seems to be a bit old and doesn’t list anything for the newer 9speed SRAM kit. I think either way, it’s not going to be an exact match on the cable pull ratios, so there may always be a section of the cassette that doesn’t mesh properly (and you don’t want a shiftmate on a ‘cross bike).

So that’s not terribly helpful is it? Basically I don’t know. It would be interesting to try, but I would definitely have my reservations.

What I can say is that the SRAM STi’s with the 10sp MTB mech works an absolute dream and means I can run (as you say) a single ring up front and an 11-32 cassette on the back. Does the job perfectly. Perhaps the best bit is having a secure chain-guide for the front ring (look at the e.thirteen down-tube mounted xcx, or two k-edge cross guards either side of the chainring) – I haven’t dropped a chain in ages :-).

So, as I read it 10 speed SRAM road shifters with 10 speed SRAM mtb rear mech is compatible. I guess that I just need to see whether it’ll work with a campag shifter as this suggests (though maybe there’ll be issues caused by tolerances being doubled up)

http://velonews.competitor.com/2008/03/bikes-tech/can-you-run-campy-shifters-with-a-sram-drivetrain-sure-why-not_73404

FYI for shimano, I have 10 speed 105 shifters, 9 speed XT rear mech and 10 spd SLX casette all working fine together on a road/touring tandem. The drivetrain also has SRAM chain and truvativ cranks.

To ask a thick question, is that including 2011 SLX/XT/XTR?

Yep, although the front mechs are different to the MTB ones.

Basically, there are 4 cable pull ratios (I’m going to copy this into a document to paste as required!):

1. Shimano 7/8/9 speed and 10 speed road 5600, 6600 and 7800 (which is where the road/mtb confusion comes in – only the hidden cable 10 speed groups below use the new pull ratio)
2. Shimano 10 speed all MTB and road 5700, 6700 and 7900
3. SRAM 9 speed
4. SRAM 10 speed (road and MTB)

Campag is another entity altogether, the cassette spacing is different, although I’m not aware of the cable pull I’ve never really seen a bike with mixed groupsets that works properly (although this is clearly subjective!).

If you want to run 10 speed 11-36 on a CX bike with STI-type levers then get a SRAM 10 speed MTB mech, it’ll be far far cheaper than Campy Ergo Power levers (assuming you already have the SRAM Double Taps) and will work properly, with no bodging required.

I’m not quite sure why you’d want to use Campy levers?

Because I have campag on my road bike and on my CX 🙂

CX currently has a 10 speed Campag shifters, Shimano rear mech (hubbub cable fixing method) with 9 speed cassette and works perfectly. Going to 10 speed would allow a single ring setup but there’s no campag mech that’ll cope with a 36.

I see – I thought you already had the Double Tap levers.

Why not go to an 11-34 9 speed cassette – that’ll do, the 36 isn’t gonna that much more use for cross.

It will be for me 🙂 I don’t use my cx bike for racing and I’m currently plenty unfit enough that I want the 36. 10 speed with it keeps all the current ratios I have less the top two (eg biggest) gears which I rarely use and can live without.