pic: Another Belt-In-Tube Drivetrain

[Cothron Theiss]

Originally Posted by Chris is me

The designers on the team are looking into ways to use smaller tubes in future drivetrains, to save weight and to allow adequate ground clearance with 4" wheels. 2.5" tall tall tubing, with rivets staggered to avoid the belts and pulleys, are a possibility. Experimenting with smaller tooth count pulleys is another option, albeit a risky one. 21T pulleys have a number of teeth divisible by 3 for easy machining, and they allow JUST enough clearance for a 2" tall tube if you stagger the rivets, but without testing I can't be certain they would be robust enough.

What are your concerns with using smaller pulleys? I assume that the belts would slip before the pulleys or belt would fail, but is belt slippage your concern with a pulley smaller than 24t?