XRAY - Model racing cars

I have a question regarding the front belt on my 011T3.

Last week I broke two front belts. It's unusual as I've only ever broken one front belt in 3 years. I usually race in fixed timing 17.5t but have recently moved up to 17.5t "boosted."

Would it just be that a faster class puts more strain on the belt or could it be that I am either running the belt too loose or too tight? Could it be something else I have overlooked?

I use a front spool.

Regards
Jason

Something is wrong.

Check the pulley's thoroughly to make sure nothing is stuck inbetween the teeth.

Also check carefully to see that the belt isn't rubbing on anything. You said you've changed classes, is the pinion rubbing on the belt or something like that.

Skiddins

Thanks Skiddins I'm in the process of checking everything now, will let you know if I find anything.

Also check the pulleys for wear. The teeth can get worn down over a period of time causing the belt to skip and possibly snap.

Thankyou.......

Ive just inspected the front pulley, its in good condition. Ive changed to new bearings and new front spool adapters and theres also a nice gap between the pinion and the belt. It's definetly not touching anything.

Question is how tight should the belt be? I am led to believe there should be about 3mm travel when pushed down from the top? Is that correct? I am using a brand new genuine xray belt. If I was to have the belt fractionally tight what handling changes should I expect from the car?

On carpet I would set it like loose enough and then still one more loose as debrit from the carpet track comes between the drivetrain and will tighten it a little. You could say that as long as your belts don't jump over during hard braking nothing is too loose. Being loose helps a lot the free running and the bearing and layshaft lifespan. And of course the car performs much better being more silent also.

My T4 has done two meetings and the belt is on the second notch.

If you ping your front belt, it shouldn't keep vibrating like an elastic band, it should barely vibrate at all and stop after 0.5s or less.

Skiddins

As for me, I had to set the excenters during building out of the box at two more loose than centered in the rear and centered in the front. But after some tracktime I loosen the front belt by one due to some debrit (the hard packed deprit not the one that is easy to remove on the pulleys).

Here's how far I can pull my belt before the car starts to lift;