Strange rubbing noise leads to belt rupture (Raptor 1)

Hi guys,

I’ve got some issues with my DIY Raptor 1 with 9 mm HTD-5M belts. Everything was working fine until the first belt snapped after roughly 800 km. The new replacement belt hold up for a while but eventually broke. With the two last belts I did always hear a rubbing noise when braking which is really annoying. I am 100% sure that the wheel pulley did not touch the motor mount nor was anything stuck between the pulley teeth. I am going through a lot of belts lately and it drives me crazy not finding the root of cause of the rubbing noise (just on one side).

Pulleys look fine, and I don’t think one of the pulley bearings is gone? Any advice or experiences with the Raptor v1 drive train is highly appreciated!


Let’s see some pictures. Your belt may be too tight

Tbh I never really changed the belt tension and kept is relatively loose. One of our group members used to change the belt tension on his Bamboo GT up to five times during group rides and went through a lot of belts as well.

Take a picture with a belt on it. And do multiple angles.

Tension looks okay but the belt doesn’t seem to be completely sittin on the pulley. Try moving the mount a mm or 2 so the belt sits on the pulley completely

Can’t move the mounts but can remove a washer. Just still don’t understand where the rubbing noise is coming from.

Your belt looks a little frayed on the motor side. Maybe it’s rubbing on one of the mounting screw heads.

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