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Is it possible to combine MTB and road gears?!

939 views 1 reply 2 participants last post by  standard3x 
#1 ·
I am just waiting for my Stumpjumper cro-mo frame to come back from Argos Cycles and I am looking for a crazy gear setup to put on it. It will be setup as a hybrid so I have all sorts of stuff on it.

I am wondering if it would be possible to combine a double road crank on the front and a standard 9 speed MTB cassette and derailuer on the rear. Say for example the following:

Rear - 9speed XT derailuer and Cassette.
Front - Ultegra Double 6500 and FSA SLK Carbon Chainset (double).

If that is possible then presumably I would need to buy both sets of levers and just use the respective ones for each?

If anyone has any thoughts, sugegstions or advice I would be grateful.

Many thanks

George
 
#2 ·
Yes, it's perfectly possible, but you have to keep a couple of things in mind: chainline and RD capacity.

Ideally, when experimenting, you'd want a frame that has a 68mm BB shell - which the Specialized SJ, I believe, has.

Next, if you're working with no prior knowledge of how the components fit together, then opt for a compact double (50/34T, 110mm BCD) instead of the standard double (53/39T, 130mm BCD). This will give you a better chance that the chainrings will clear the chainstay, and make it easier to bodge if it doesn't.

The FSA SLK Carbon chainset is available in either ISIS or MegaExo versions. For maximum chainline adjustability choose the ISIS version.

The MegaExo version has a fixed spindle length that is compatible with 68mm BB shells and 70mm Italian BB shells. Fitted to the Specialized SJ, this will give you only 2mm, maybe 3mm of adjustment using BB spacer(s).

If using flat bar shifters, then opt for the Shimano FD-R44x series (eg FD-R443) front derailleurs OR modify a mtb FD by grinding down the outer cage plate to better follow the curve of the largest chainring.

If using road STI units, then opt for road FDs. The Ultegra FD-6500 is a good choice, but an older designated 8-speed Dura Ace or Ultegra FD would be better as they have slightly wider cages (to help eleiminate chain rub on the inner surface of the cage plates).

As for the RD, choose the SGS long cage version.
 
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