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possible to build road bike w/mtb drive train ?(15 posts)

possible to build road bike w/mtb drive train ?milt51
Feb 27, 2003 4:36 PM
I am curious if it is possible to build up a road frame using sti shifters & brakes using mtb crankset ,bb &cassette? Would I have to build a rear wheel using an mtb hub?Any suggestions or advice ? I'm quite willing to use quality parts.
Thanks Milt
no problemDougSloan
Feb 27, 2003 4:43 PM
The Shimano road and mtb stuff is interchangeable. You can use a road hub and a mountain cassette; road bb and mountain crank. Go full XTR, what the heck?

The one thing I'm not sure about is whether a left STI shifter will pull the right amount of cable for the mtb front derailleur you'll need. Anyone?

Works no problemJoe Connell
Feb 28, 2003 9:56 AM
My commuter is set up that way, well it's a mountian frame, and I have all mtb bike parts except the shifters and Crankset. But yes, the front mech works fine, although it might shift better with a road front mech. I havn't had problems shifting the front even with the mtb mech.

Feb 27, 2003 4:52 PM
You must use road hubs with 130mm spacing on a road frame, but shimano road hubs are fully compatible with shimano mtb cassettes.

Unless you need a ultra-low gear for some reason, I'd skip the mtb cassette and get something like an 11-23, combined with 44-32-22 chainrings. This will provide the same top gear ratio as a 52/13 and a low gear that's lower than a 30/27, typically the lowest ratio for a shimano road triple. You always have the option of using an mtb cassette, but the large jumps between cogs on an 11-34 are not generally desirable for road use.
Why??? (nm)Alexx
Feb 28, 2003 4:15 AM
probally for a townie !!!the bull
Feb 28, 2003 7:38 AM
If I was building an around town bike.
thats the drive train I would want with flat pedals.
If you have to ask why, you're taking this too seriouslyretro
Feb 28, 2003 8:36 AM
Jeez, cut the guy some slack. Maybe he lives in San Francisco, maybe he's 82 years old, maybe he just wants some low gears. I've built my last two road bikes with what amounted to mountain bike drivelines, and they're perfect for the riding I do. It's fine with me if YOU want to run a 53-11, but I wouldn't use those gears once a year. One of the dumbest things we do as cyclists (except for wearing black) is to set up every bike like Lance was going to ride it in the Tour.
I might be wrong , But,jiggs
Feb 28, 2003 10:40 AM
I agree with 130 hub, & any 9 speed cassette,XT, XTR, 105, ult, Da, and any shifter with that , XT, XTR road STI , even sram (SRAM rocket,attack) but I couldn't (after much effort) get a MTB shifter to work with a road (ultegra) front derailler and MTB crank (XTR.) Shimano say that the throw is different (something about 10-10 vs 10-12) I realize it might be just the derailler/crank combo but would like to here from someone who uses road FD and mtb shifter/crank.
well front deraillers are cheap anyways, but I'mJoe Connell
Feb 28, 2003 11:13 AM
using an ultegra shifter with an acera (think cheap mtb) front mech, and it works fine with a road crank. It was simply a matter of seting the limits right and then setting up the right tension. I've been using it for around six months now and haven't had any problems, I haven't even had to adjust the cable tension. I'd say try it, and if he has problems, get a new front derailler. It should only cost an extra $20/$30 if he needs a new derailler anyways.

my troubles might have come from setting up thejiggs
Feb 28, 2003 12:02 PM
XTR crank, ultegra front derailler, SRAM shifter for a Mount Washington hill climb and needed the small and medium chain ring. Probably harder to adjust for those small rings.
XTR Shifters, Ultegra 3x FD & Crankset - Works Great (nm)TFerguson
Mar 3, 2003 1:30 PM
Clearance for ChainringsThe Kid
Feb 28, 2003 2:56 PM
In general, road frames don't play well with MTB cranks.

Many MTB frames have their chainstays crimped, dimpled or ovalized to make room for the smaller chainrings so close to the BB shell. On the other hand, many road bike frames are built without such clearance, and often use round section stays to maximize lateral stiffness.

You may think you can get around this by using a longer bottom bracket spindle than normal for your chosen MTB crank, but then you may offend the gods of chainline, and your mongrel bike may never shift correctly.

Not to say that it's impossible, or that you shouldn't consider it, but that you should take a good look at all the parts and the frame before buying and assembling them only to find they don't work together.

Good Luck!
The Kid
other way around?DougSloan
Feb 28, 2003 3:21 PM
Wouldn't using road rings on a mtb, rather than mtb rings on a road bike, be the problem? Assuming same spacing, larger rings would be a problem, not smaller. If not, what am I missing?

I used to run a 55 ring on my old (1980) Bianchi, as we were stuck with 13 tooth small cogs back then. The ring just barely touched the chain stay, just enough to rub the paint off. I thought I was cool.

MTB Front Derailleur and ROAD STI shifters DO NOT WORKzmarke
Mar 2, 2003 4:04 PM
according to Shimano Tech, my LBS, and my own trail and error. They have different amounts of pull.
triple levers with triple crank?should work!nmthe bull
Mar 3, 2003 3:25 PM