In need of ideas - Belt falling off

Hi, just lately, the belt on my Westwood T1200 has been driving me mad, it keeps falling below the pulley no matter how many belt retainers I put to prevent this.

I'm just looking for people to suggest how they prevent their belt from coming off.
Thanks, matthew

I had an issue with this on the CQ. What I eventually did was I got a belt one inch shorter. My 87 inch belt fell off probably every 200 yards. Since the 86 was put on, no belt issues...at all. That should be all you need to do

Interesting. Do you have any retainers holding the belt on at the minute? I tried putting an idler in to keep tension on the belt, but I can't get the engine to run right, might be swapping it because I've been having problems with stuck exhaust bolts and stripped threads driving me up the walls. I've got 'deep grooved' pulleys in and even still it's coming off.

try the next size down belt?

Yeah that's what I might have to do. I just went through my collection of belts and put them on 1 by 1 until I found one that fitted. I'll admit, it is quite long so I should be able to go down a few inches. As I mentioned, I tried putting an idler in to keep tension on the belt, but never really tested it out. Would this do the same thing or would it be better to go for a size down belt?

I had problems with my old simplicity too. Changed the retainers a bunch of times but it would keep getting jammed in between them.

Yeah, I was thinking of fabbing some belt retainers like this