Belt Tensioners

Anybody know where I could get belt tensioners on short notice?

Usually for time, weight and space reasons teams end up building their own belt and chain tensioners. There’s no comprehensive guide to doing ithis that I’ve found but you might get some ideas from my drive train presentation at

The chain tensioning section starts around slide 26.

Do you mean for toothed belts like from Gates, or for the polycord (round urethane belts) teams often use in their collectors?

For the polycord, you can just cut and remake the loop shorter (heat if solid, barbs if hollow).

For Gates belts, you can probably just make your own tensioners. Heres a picture of 1625s tensioner in a gearbox

I don’t know how well this idea worked, but another team just used the andymark chain tensioners.

Keep in mind I don’t have a lot of personal experience with either of these two methods, I just saw pictures.

These chain tensioners worked great for us last year. Made it to the Hawaii regional semis without any belt slippage. Hardly any wear on the delrin tensioners.

Using belts on our drivetrain for the first time, we’ve been having fun with belt tensioning issues. Here is what 842 has come up with to take out that last bit of slack from the belt (see the light grey plate on the left side of the image; it is the support for the idler poking through the hole in the frame). Constructed from fiberglass pultrusions and ball bearings for the idler.](