Co-Motion isn’t known for building over the top show stoppers. Rather, they bring stock models that represent a cross section of the bikes they build day in and day out. This year, they showed the usual fleet of tandems and singles with one surprise up their sleeve. Co-Motion put one of their CNC machines to use and produced an aluminum belt drive cog to work with the Alfine Di2 setup on their city bike. It was well executed, so much so, that they took home $1000 prize from Shimano and Gates for the best Di2 Gates Belt Drive integration.
Push button shift your way pass the break for more images.
To keep the gear range where they wanted it for a city bike, the aluminum center track cog was machined with 28 teeth.
Clearance is tight, but it works, and works well. The guys at the shop had fun test riding the bike before the show, and ensured me there is no belt rub.
This build uses the external battery. The next iteration however, will make use of the new integrated seat post Di2 battery.
Thanks to the space inside the house made Co-Motion eccentric bottom bracket, they were able to run all the wiring internally. The wire enters the down tube, and isn’t see again until it exits the rear chain stay.