kreative

Hello, I am planning to build an all-around bike (light loaded touring, commuting, distance, some trail), and was hoping to get some help on a bike build. Right now I am looking at the All City Space Horse as my frameset, and looking to set up with road drop bars and brifters. I could go Shimano or SRAM, but trying to find a setup that works. I am thinking of mountain bike type gearing in order to be low enough to climb with load, but not sure what would work. I have a road wheelset already, so not sure how that would factor into my choices.

Frameset: All City Space Horse (or possibly Surly Cross Check)
Wheelset: Shimano Dura-Ace C24 (with 7850 10-speed hubs)
Brakes: TRP CX8.4 V-brakes or Paul's Touring Canti's
English threaded BB


Shimano Setup:
Brifters: Ultegra 6703 triple
Crankset: Shimano XT 780 Triple
Cassette: Shimano 10-speed 11-36
FD: Shimano XT M780
RD: Shimano XT M780 Long Cage
Chain: Shimano 10-speed

SRAM Setup:
Brifters: SRAM Rival
Crankset: SRAM X9 39-26
Cassette: SRAM PG-1070 12-36
FD: SRAM X9
RD: SRAM X9
Chain: SRAM 10-speed

I guess the big question is if the mountain groupsets would work with the road brifters (either Shimano or SRAM) and my road wheelset. Any input would be really helpful and much appreciated.

chriskmurray

I am not sure about the front shifting but to use 10 speed road shifters you have to use a 9 speed non shadow rear derailleur with your 10spd mtn cassette and chain. I have set up a number of bikes with this and this same set up was actually suggested to me from a Shimano tech rep.

kreative

Thanks Chris, so the 9-speed rear derailleur will shift all 10 gears? i.e. dependent on the shifter?

Tim_Iowa

The 6703 brifters will not play nicely with either Deore XT derailer. Get the FD-6703 for the front; MTB FD's have a longer reach because they have wider cranks.


I have no personal experience, but it seems like Zinn agrees that (for Shimano) 9 speed MTB rear derailer's work with 10-speed road cassettes. Get a non-shadow, non-Rapid Rise RD.

You have a nice build going for an all-rounder. I set my Rivendell up similarly: Campy road triple crank, 11-34 9-speed cassette. But I use friction bar-end shifters, so I can use any old MTB derailer.

himespau 

Are you sure about that wheelset for light trails and loaded touring?

fietsbob

stick to road drive trains and it should work.. Mixing causes less compatible combos.

Only the fact that the left bar end shifter is not indexed , will that work on both road brake levers

and either a MTB or Road FD and the appropriate crankset..

in the back the numbers have to match 10 to 10, & 9 to 9,
though 8 can work with 7 .. as the spacers between the cogs is similar..

above 8 they get thinner as the drive side space available for Cogs, is no wider.

"speeds" is really just how many cogs are stacked up on the rear wheel cassette..

Ratios is what a 'gear' actually is ..

after adding the 8th cog nothing got significantly wider , so the rest of the designs
were about packing the extras in the same available width.

so RD throw is about the same

chriskmurray

Yep, it shifts the entire range almost as well as an all road 10 speed group. I have set up a good number of customers with this set up and they have never once complained about shift quality and they all loved the range it gave them.

kreative

Thanks Tim for the info and link. Will the FD-6703 shift a MTB crankset ok since they are wider than road cranks? Someone had told me to match the crankset and derailleur...

dbg

I'd go slightly wider (heavier) rims. And my working definition of an "all-around" bike would include fenders and lights (probably dynamo powered). But that's just me.

himespau 

I addition to needing heavier duty rims, the whole idea of using a total of 36 (or 44 depending on the version) spokes for a wheelset in an all round bike that's going to see some touring/off road just seems way too low to me.

likebike23

My understanding of mixed road/mtb groups is that it can be done. The front derailleur should be a road derailleur if using road shifters. From what other members have said, the Shimano Tiagara triple front works with mountain cranks well. The rear derailleur can be a mountain derailleur, but as others have said, a 9 speed model will work best. A mtb "shadow" rear derailleur should work, as it is just a term for designing the derailleur to not stick out too far and catch on branches. Dynasys derailleurs are the ones that should be avoided. As far a SRAM is concerned, I'm clueless. If I'm wrong on any of the above, someone will chime in. Hope that helps.