You could cut the tension with a smooth metal wheel.

Bought some more transmission bits today. First up is shorter belts.



I bought a cast iron caster to act as a pushing tensioner. Built a little bracket and hinge out of tubing. I temporarily clamped it in place here. This should work ok once I bolt it in. I hope.



Here's the nearly complete tensioner. I'll weld it and drill holes for cotter pins tomorrow, hopefully.