[wgscott]

One of the very few regrets (probably the only one) I have about my ultegra Di2 road setup is the inability to run a triple in the front, which for bike touring or an occasional insane hill would be kind of nice to have. Being in my declining years, it could also be a hedge against the future, should I have one.

Unless I am reading this wrong, it looks like Lennard Zinn says that if you purchase XTR (mountain bike) front and rear derailleurs, you can use these with Di2 road shifters.

You can run a full XTR Di2 drivetrain with your Di2 road levers (you could use any Di2 ST or SW Di2 switch, like climbing, sprint, or TT switches with it). That would be analogous to mixing 10-speed ST-6770 (Ultegra Di2 shifters) with 11-speed RD/FD, or 11-speed ST-6870 (Ultegra Di2) or ST-9070 (Dura-Ace Di2) with 10-speed FD/RD-6770 (original Ultegra Di2). Both of these road combinations do work.

Tech FAQ: Mixing Shimano road, MTB Di2 derailleurs - VeloNews.com

Anyone have this/seen it done/have any experience with this?

 

[Steve B.]

Saw this over on bikeforums.net

From what I have read you can combine DI2 STI shifters with the MTB DI2 XTR mechs, what you cant do is have a DI2 road F/D and a MTB DI2 R/D, the mechs both have to be either road or MTB DI2s

This is correct. The problem with a road triple setup is the XTR derailleur is optimized for mtb size chainrings. If you're ok with running a MTB crankset, with a top gear around 44x11 it will work with road levers. You coud even do a SRAM XX hub, and get a 10 tooth cog to get a bigger top end.

 

[cxwrench]

The other thing is that for most road frames there is no way to mount an XTR Di2 front derailleur. Tried it already. And yes, you do have to use both derailleurs for it to work. No way around it at this point.

 

[velodog]

IRD has a 46x30 crankset if you're interested in something like that. I have one and it works with an 11spd Campagnolo drivetrain.

Defiant Wide Compact Road Crank Set ? Interloc Racing Design / IRD

 

[wgscott]

The other thing is that for most road frames there is no way to mount an XTR Di2 front derailleur. Tried it already. And yes, you do have to use both derailleurs for it to work. No way around it at this point.

I have a clamp-on mount with a straight steel seat tube. Would that work?

 

[cxwrench]

I have a clamp-on mount with a straight steel seat tube. Would that work?

Lucky you, yes. There are 2 clamp mounts, one w/ a 'high' clamp and one w/ a 'low' clamp. depending on water bottle mounting location and possibly tube shape you pick the one that works best for your frame. They're these 2:

Shimano XTR Di2 SM-FD905-H
Shimano XTR Di2 SM-FD905-L

Looks like msrp is $25.00.

 

[wgscott]

Thanks. If I do anything, I think I might first try an XT 11-speed 38 X 28T with the current FD (since I can just slide it down a little bit). My current crank arms are 172.5 mm. I have been doing some reading and am wondering if I should change that. I'm 5'9" (and shrinking) with a short (29") inseam, so I am wondering if the 170 or even 165 mm might help, especially since most of the time I am cranking up hills and my ankle range of motion, even before the break, kind of sucks. (The XT is available in 175, 170, and 165, but not 172.5).