Picture it. A very attractive young woman dressed to the nines walking with a somewhat grizzled and tough looking older fella. A few heads might turn. Some just won't get it. But hey, ain't love strange?
All right...enough of that. This is the first Di2 bike I've had the opportunity to build. Let me say that Shimano has knocked it out of the park with the full internal wiring kit. I've still got a lot of work left to do on the frame, but I wanted to mock everything up and make sure that all is copacetic with the wiring before I finished up the BB area and seat stays.
The goal for this bike was simple. Make a clean layout for the wiring and make it easy on the eyes. That meant tuck the battery away out of plain view. I also wanted to drill the holes for the wiring in as many thicker cast pieces as possible rather than just the tubing. For the spots on the seat tube and down tube where this wasn't possible, I made some reinforcements for the holes. I also had to make a front derailleur braze-on. Here's the problem. A Max seat tube is very wide (approximately 36.5 mm) where the braze-on is placed. Putting a standard FD braze-on, which are meant to go on a 28.6 mm seat tube, on the tube positions the derailleur further away from the centerline of the bike compared to usual. This hasn't been a problem for standard front derailleurs. There's plenty of throw. Looking at the Di2 derailleur though, you can see right away that the cage does not go as far inboard as a standard derailleur. So what I did was make a tab and reinforcement and position it exactly to Shimano spec. This meant that the derailleur itself is very close to the seat tube but it is where it needs to be in relation to the crankset.
Have a great weekend!