K, I went through a few belts last season, just ripped them to pieces, I need something for a high hp sled that will last and there are only 1-2 million to choose from, any good ideas on a specific belt I should look for. Thanks

Before you go buy new belts

are your clutches in proper working order?

When was the last time they were rebuilt?

When was the last time you re aligned them?

Maybe your engagement RPM is way too high anything over 5000rpm is very hard on belts

Alignment, alignment!, and even closer ALIGNMENT! Make absolutely sure you don't have a broken motor mount. You don't mention what you are running, but some sleds are pretty hard on them. Once absolutely sure of your alignment, install a torque arm to gaurantee alignment while under load- especially if you are having trouble blowing belts or motor mounts. Then install an OEM belt - they're tough to beat for durability/price.

If you have allready done the above, there's a good chance your belt is running out of the top of the primary. That gets ugly fast. Has it ever flipped inside out?

No Its never done that, it just chews them up, I'm running the 680 tripple all worked out, i'm not sure what the belt is, I'll check the mounts and the alignment. If the engagement rpm is high how can I correct this.

Lot of good info above, I am going to add one more make sure to take a look at the motor mounts. I tore up a belt last year on my XC 600, checked the alignment, it was good, bought a new belt and went on, well not for very long, as we ran out of snow and I probably only put another 100 miles on it. While getting it ready for the season, I noticed that while reving up on the stand, the engine was moving a little more than I thought was right. I looked and looked at the motor mounts while the engine was still in, did not see a problem. Damn, I guess I'll have to loosen and partially pull the engine to get at the mounts. Sure enough, after a little swearing, I got he left front motor mount out, and it had sheared on the back side. The back ones don't usually go, but the front ones, especially the left front do, from time to time. I replaced both fronts, the engine does not move around as much (they all move a little, how much is too much? ) and maybe I'l recover some of that lost top end speed this year. w00t

The easiest visual cue to a broken / soft engine cushion (besides scrapped belts) is to check the front exhaust joint(s). They will be quite polished horizontally from the engine excursion North & South.

Ok, so we are talking about an Ultra. You mention high engagement. They do need to run a little higher than some to cover a big 'ol flat spot down low in most. What are you coming in at? Tripple/tripple or single? How are you planning on using it?

Another easy way to check for a motor mount/alignment problem is to check for way hot belt temp after a couple hard passes. 1st run will be better/faster than the second. If the alignment checks out at that point, and you know your clutches are ok, it's time to get dirty and check out that left front mount closely.

XCR's tear the left front out repeatedly without the use of a torque arm. If yours is running good, there's no good reason it won't do the same thing...

If it does check out, then it's a pretty sure bet your clutching setup isn't working for you at all. It could be slipping badly, generating all the heat for that reason.

Part of it could be in how you ride. If you ride really aggressively and are blipping the throttle a lot, you will burn up belts faster.
I have a feeling that your belt life issues are more than just how you ride.
Octane