It’s one thing getting the chain timing right on a tandem. It’s a whole ‘nother challenge when you’re putting the shifting in the middle of it, rather than running a traditional cassette and derailleur. But Co-Motion figured it out for this stellar NAHBS show bike, which combines Gates Belt Drive with a Pinion gear box. And while Co-Motion didn’t use it, Cinq was showing off a better way to control internal gear box and hubs from multiple brands…
One would imagine there are enough things going on when off-road touring in tandem, so reducing drivetrain worries seems like a good idea. But to pull off the gear box with belt drive, Co-Motion had to rework the order in which things transfer to one another.
On the (rider’s) left side of the bike is the timing belt, keeping both riders pedaling in sync.
On the right is where the magic happens. Both riders’ output is sent to the gear box on the outer belt, which replaces the crank arm in a traditional setup. The inner cog is where it would be normally and is the one that sends power to the back wheel. It’s all controlled up front with a customized twist shifter on the bar.
Co-Motion Steelhead tandem gravel bike
They were also showing off this new Steelhead tandem all-road/gravel bike, which made room for larger WTB tires.
The frame is made with butted Reynolds still tubing and can be ordered in custom geometry and sizing, with your choice of a traditional welded construction or this fillet brazed version for a slight upcharge. The carbon fork is new, too, offering wider clearance and boost axle spacing. Check them out a Co-Motion.com.
CINQ drops new shifters for internal geared boxes, hubs
One of the issues with Pinion’s internal gear boxes is the shifters…they need to have dual cable routing to work well (with many models, but not all). One cable pulls in each direction, moving things where they need to be. Which means you end up with oversized single-unit shifters like what’s shown on the Co-Motion bikes.
Cinq has been working on a solution to make the shifters more ergonomic and familiar, and now they’re ready to launch with both drop bar and flat bar versions. The kits are on Kickstarter now, here’s the video:
Two models will be available, the Shift:R Road uses drop bar levers with integrated hydraulic brake master cylinders and lines from TRP, and the Shift:R Tour with individual thumb shifter paddles. Both will replace part of the mechanism on the Pinion gear box with a Cinq attachment to make it all work.
The Pinion flat bar shifters will look like these, which are their version for Rohloff internally geared hubs. So, even if you don’t run the gear box, you’ve got options for better shifters. Check them out at cinq.de.