I was just wondering if anyone has build a Di2 tandem, 11-36 cassette using JIS square tapered bottom brackets. Rear spacing is 145mm & I'll be using the Gates centertrack timing belt. I'll also be using a double crank set, not a triple converted to a double. BB shell is 68mm. If you have done this & happen to remember the lengths of the bottom brackets that have worked well for you, it would be very helpful.
Best regards