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Can I run MTB cranks on a road bike? Newbie question.(8 posts)

Can I run MTB cranks on a road bike? Newbie question.Papa Wheelie
Apr 10, 2003 7:46 AM
Is there any technical reason that it wouldn't work? I am building up a road bike, short on funds, and I have an older set of Race Face cranks w/ new 36t and 48t rings just sitting in my parts box begging to be used.

I know they will probably be heavier than a road crankset, but this bike isn't going to be raced. Fun rides, unstructured training, commuting.

Thanks in advance for any knowledge that you can share.
re: Can I run MTB cranks on a road bike? Newbie question.chanhoward
Apr 10, 2003 8:39 AM
No problem at all. If your MTB crank is triple(most MTB crank are triple)Just make sure that your road front shifter can support triple crank.
Also make sure the road front deraileur you use is specifically for a triple or double crank, whichever is applicable, as most road front De are double or triple specific.E.g, shimano Dura-ace & Ultegra have front deraileur specifically for a tpl or dbl crank.
I am doing the same thing as you, using my XTR crank on my road bike when I am not using my MTbike etc as I am tight on cash.
Hope this help
Happy riding
Howard Chan
Yes and Noss-nyc
Apr 10, 2003 10:34 AM
Yes:
any mountain bike crank should work on a road frame as long as you have the correct bottom bracket and clearance is not an issue.

No:
a Shimano "front road" derailleur will not work with a mountain style crank becasue they have different amounts of pull. The shifters are also not compatable for the same reason. Also, most road bikes are bottom pull derailleurs whereas most mountain bikes use a top pull. ("pull" should not be confused with "swing"). Rear derailleurs are not an issue, road and mountain are fully compatible.

A work-around is to get a cheap "bottom pull" derailleuer for your MTB crank this way you can use the crank and your current shifters on a road bike. They can be found cheaply on eBay or Nashbar.
http://www.nashbar.com/profile.cfm?category=83&subcategory=1037&brand=&sku=2988&storetype=&estoreid=

hope this helps!
Quick followup question...Papa Wheelie
Apr 10, 2003 10:46 AM
Ok. I am only going to run 2 rings on my mtb crankset. Would a road front 'D' work in that case? Not going to run a triple up front.

Complete drivetrain would be something like this:

Shimano 8 speed barcons
Race Face turbine LP crankset, 36t and 48t
8 speed chain
sram 12-26 rear casette - 8 speed
ultegra rear D, short version
105 front D, double capacity

Haven't bolted it together yet... but it made sense to me on paper at one point. I know the gearing is a bit lower than most road bikes but I figure I'll need more help getting up hills than down.

Thanks guys, I really appreciate it.
Mixed resultslaffeaux
Apr 10, 2003 11:13 AM
You may want to run a search on the 'cross board. Some people have had no problem running MTB front deraileurs and road shifters, while others can't seem to get it to work. CXers mix mountain and road components quite a bit and have dealt with a lot of the issues before.
2 Issues...ss-nyc
Apr 10, 2003 12:23 PM
1 MTB shifters work with MTB derailleurs and road shifters work with road derailleurs. The amount of cable pull a mountain and road "front" derailleur need/use are different...it is based on the shifters and has nothing to do with double vs. triple rings. Even if you only run 2 rings on a triple crank the derailluer still needs to pull to the appropriate postion. If the race face is a triple then you need to get a triple derailleur even if you only use 2 of the 3 rings.

The barcons, as far as I know, are road shifters and will work with any compatable road speed rear or front derailleur. 8speed shifter with 8speed derailleur, 9 with 9, and so on.

2) It is possible, although not recommended by Shimano, to use a setup similar to what you are trying. Front derailleurs also have a shape to them which is to match the amount of teeth on a crank. So a road der. is set for 52/42/30 or 53/38 whereas a MTB crank front der. is set for a 24/34/44 or in the case of XT 26/36/46 and I think XTR can even go to 28/38/48.

If you are set on the barcons with drop bars, you should use the road front derailluer that has the most flexability to it and that probably is the 105 but remember that I think you still need a triple front der. if the race face is a triple even if you only use 2 rings.

As mentioned by the other poster, try the CX board since this has probably been done many times before.
Barcons.....Rusty Coggs
Apr 10, 2003 2:19 PM
....are friction for the FRONT and work with any derailer.If he uses the crank with only 2 rings and an appropriately short BB then a double front derailer will also work,but if he uses small rings,the the derailer cage should be aproproate to the rings,but there is also a lot of latitude there.
ThanksPapa Wheelie
Apr 10, 2003 4:23 PM
I did a little searching in the cyclocross forum and it looks like it can be done w/ a narrow enough BB. I'm going to give it a shot. Thanks for your input!