# Front Derailleur choice. Road or MTB (105 STI shifters)



## slider_phil (Aug 27, 2014)

I've done a bit of googling around and I think I've only just confused myself even further. I've started mucking around converting my old 29er to a drop bar bike, intending to do some commuting and light touring.

I've bought 11spd 105 Shimano shifters and have got them working with the rear XT 11spd derailleur using the Wolftooth Tanpan. However I think I want to run a double in the front (38-28 most likely) using a MTB crankset and it looks like a MTB front derailleur wont work with the road shifter from what I can gather by reading around.

I'm sure someone on here has done something similar and can share their experiences. Will a Shimano 105 front derailleur work with the MTB 2x cranks? or can the MTB derailleur be made to work with the 105 shifter. 

What about Road cranks on a MTB, will they work with a standard 73mm BB? I've just noticed you can get Ultegra with CX rings (46-36) which would be awesome for commuting, but may be limited a bit with a loaded climb with the 10-46 rear cassette and 36t front.

Thanks in advance for any advice!


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## Mr Pig (Jun 25, 2008)

In theory there are a lot of parts that shouldn't work together, but do. For example, you can often get front derailleurs to work with shifters that don't match because the movement is not as critical as it is for the rear. The bigger issue is usually clearance of the chain-rings and the length of the cage. 

It's the same with crank-sets. If you get it to physically fit it'l work. For example, fitting larger rings on a MTB frame can cause problems with them hitting the chain-stay. Even if they are just close to the stay they can hit it under load, and those guys can cut through the stay in no time! 

So the answer is, it depends...


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## Volsung (Nov 24, 2011)

I dunno anything about shifter compatibility but you can put a 34t ring on the Ultegra CX cranks. They're like 12 dollars on Amazon.

I don't live somewhere with hills a 34-46 couldn't get me up.


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## slider_phil (Aug 27, 2014)

Thanks for the info, guys 

Still tossing up what to do. 1x is the obvious choice but I can only run a 36t maximum on the frame in that configuration.

Cheers!


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## SteveF (Mar 5, 2004)

Two ring cranks are pretty easy to shift-all the way left or all the way right. Most front shifter/derailer combos can manage that. It's mainly where cable pull variances or indexing a 3-ring crank gets involved that you run into issues. I would get the derailer that closest matches the chainring configuration you're using-for 38/28 rings that would probably be a mtb derailer.


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## slider_phil (Aug 27, 2014)

Ordered a 38-28 XT crankset and a matching derailleur. Will see how it goes 

I've got an 11-40 and 11-46 cassette at home, so range will be about perfect for me. Cheers guys


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## alias (May 9, 2005)

let us know how this goes. It's for sure something many would like first hand feedback on!


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## life behind bars (May 24, 2014)

I don't know about 11 speed but I run an Xt front derailleur with Shimano 9 speed road shifters and it works fine.


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## slider_phil (Aug 27, 2014)

alias said:


> let us know how this goes. It's for sure something many would like first hand feedback on!


Definitely!


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## paramount3 (Jul 13, 2014)

slider_phil said:


> Definitely!


Well Phil, how did it go? I thought GRX would solve all of this, but for some reason the 2x GRX cranks are 46/30, instead of something more useful like 40/24. So I'm wondering if I can run GRX shifters with an MTB double crank.


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