[DampRobot]

We had similar experiences at SVR.

We run a 6WD WCD VersaChassis setup with 4" wheels, omnis in front, and either VersaWheels or VersaWheels DT as the center and back wheels. Dropped center, VersaTrucks, and CAM tensioning. We used 4 CIM, 2 Minis in a 3 CIM ball shifter at Davis and took out the Minis at SVR. The center wheel was direct driven off the ball shifter output shaft, and the front and back belts were driven by 130T 9mm wide VP belts on 24T pulleys. We were traction limited in both low and high gear.

At Davis, we played really, really hard defense, and didn't have any problem with the belts (although we tripped the main breaker a lot more than we would have liked).

At SVR, we suffered 3 separate belt failures. The first belt broke after about 4 matches. It was a classic overtension failure, with the tensile elements of the belt pulled out, and no real wear on the teeth to speak of. We replaced the belt, and assumed that it broke from a combination of a regional and a half of really hard play and overtensioning. I went through all the belts and made sure they were on the loose side of correctly tensioned. We suffered 2 more belt failures throughout the rest of the regional, with nearly identical failure modes, and in different locations in the drivetrain. I inspected the drivetrain, and there were no obvious alignment problems, debris, etc. that might be causing the problem. The second two breaks occurred with belts that I'd consider "quite undertensioned", yet they looked like classic overtension failures. I brought the belts by 971's pits, and they agreed that these all looked like overtension failures. When I took a look at their drivetrain later, I noticed they had the same diameter wheels, similar pulley diameter, the same belt width, and tensioned their drive belts more than we did, yet suffered far fewer belt failures.

I've heard through the grapevine that VP did have quality issues with their drive belts this season, and my own experience and anecdotal evidence seems to support this. Multiple teams seem to have seen belts fail in this way, and that teams using Gates belts that I talked to didn't see these types of failures anywhere near as frequently. Of course, anecdotal evidence does not a strong conclusion make. If this is a quality issue, I hope VP addresses it (and lets us know that they have). If this is more a user issue, I hope the community learns how to use these products without having to worry about them breaking.