When our boss came to us with a Santa Cruz Stigmata Cyclocross frameset and a pair of Mavic Crossmax SLR 29er wheels we knew some fun times lay ahead.......Make this work with XTR Di2 he said.
The Mavic wheels were an obvious choice as both Frame & Fork on the Stigmata come with the bolt through axles to keep things nice and stiff, as most of us here are predominantly mountain bikers we know the benefits of having these available.
First things first, had it been done? We couldn't find any successfully completed attempts, or any actual attempts at all! What can go wrong?
A couple of calls to Rich, the Shimano Tech Expert later and we had the ball rolling, half an XTR Di2 Groupset, BR-R785 Hydraulic Road Calipers and ST-R785 Di2 Shifters were the starting point. Not one for keeping things easy Craig wanted a Rotor Chainset with a Q-Ring, but also a Narrow Wide ring to keep the chain in place.
A quick call to the Rotor Crank distributor and we managed to source ourselves one of the New Rotor 3D CX Chainsets with a Ceramic BB, and a QCX1 Narrow Wide Q-Ring, interesting to say the least. Its possibly one of the only chainrings with the Narrow Wide profile that are available above the 36t mark.
We wanted to go with an 11-40t XTR Cassette as it should aid climbing on some tough cross courses, this was the obvious choice as no road cassettes reach to that ratio. This was also one of the main reasons for the Mavic Crossmax wheel choice, 11spd MTB cassettes have a different inner width to road cassettes, and as such will not have fitted on your usual cross wheel.
Another quick wee phone call to Rich and we had ourselves a build day! Rich was kind enough to come to the shop and offer his services showing us how to setup and adjust the Di2 kit and teaching us some of the hidden capabilities the electronic shifting has to offer.
So what are the shifting options when you have 2 Di2 shifters and only one derailleur? The options are endless! We opted to shift up on the right and shift down on the left, this can be programmed to shift in any way you can dream of.
Shifting is unbelievably smooth at the rear, and the Q-Ring upfront is definitely going to turn some heads and keep the chain in check.
After Rich had worked magic we set about finishing it off, 3T Ergonomic bars with Supacaz Bar Tape, Shimano PRO Tharsis XC Stem with internally mounted Di2 Junction box, keeps the front end looking clean and cable free, also means the topcap is no longer required, again, thats going to turn some heads! Thomson Seatpost and WTB Saddle finish it off.
So, The answer to the original question, can you run 1 x 11spd with a mix of Road and MTB Di2 parts? Yes, you can.
We would like to thank Rich the Shimano Tech expert for his help, both Dave's from Madison for parts and moral support, Gregor from Silverfish for the Bar Tape and Bar End Caps that don't "Faw Oot" Matt at Mavic for the wheels, Jungle Products for the Frame & Fork.