What is the max teeth or "size" for motor pulleys for a belt drive motor?

I’m trying to get the right gear ratio and I’m reconfiguring a board, but I’d like to do so with minimal adjustments to save time and money. I’ve got 14T pulleys now, but want to go to 17T. Not sure if it matters, but it’s for some 85mm thane wheels. They are 160kV motors (I think). Is that feasible?

Is there a rule of thumb of maximum pulley/teeth for motor pulleys?


1 Like

Few things. You will need a caliper, and your teeth measurment for the wheels. You must also measure the size of the motor pulley, making sure it don’t hit the wheels (not much of an issue for 85mm wheels).

If i have to ask, how many teeth does your wheel pulley have?

The motors are fine but are you trying to have speed on your motor set up?

1 Like

I actually already bought a caliper to pull off the old motor pulleys. Just some random post on reddit and I bought it… lol

There is quite a bit of clearance I don’t think that will be an issue. If it becomes an issue I’ll just deal with it.

For wheel pulley I will be picking up the 40T kegel from Onsra. I currently have the 45T from them, but I want the higher top speed with lower 2.35 gear ratio. I’ve read quite a bit and most agree that 2.25 is the sweet spot, but I don’t want to have to modify too much. This board has just been such a pain in the ass… as you already know. :joy:

edit: yeah I want some decent top speed on it. i love the torque, but having top speed on flats limited to like 22mph is just kind of boring imo.

1 Like

I gotcha. Thanks for the info, so the results is this (ignore the battery part and speed. I did not measure that, but ratio.):

As long as the motor teeth isnt hitting the wheel teeth, you’re good.

However, do you know your center to center measurement? If you do, I’ll give you the belt size as well.

Edit: your max speed will be 26mph with this load out.


center to center I guess you mean motor pulley “axle” to wheel pulley “axle”, hard to get exact measurement, but it like 2.9" or 73mm

1 Like

290mm belt. That’s all you need.