Every thing else being right, the biggest enemy of a belt is heat (caused by whatever reason). When you are riding a snowmobile, I would guess that extremely cold air is being forced into the clutch housing keeping the belt nice and cold except under the worst possible conditions.

Just my 2 cents.

 

As stated in previous post, the biggest enemy of a belt is heat. Snowmobiles are ridden in conditions that favor a "cooler" belt.

Also, if I'm not mistaken, "Low Range" is built into a snowmobile clutch system... you have no choice in the matter. It moves from low range to high range as it shifts up through the gears.

I know the guys who say "use Low Range" will say "see". However, the Polaris ATV's are not required to use Low Range unless they are being driven at speeds under 8 MPH, towing heavy load, or driven under adverse conditions.

To be honest, the part about breaking in the belt and clutch makes the most sense so far.

 

I did not imply that all belt problems would be solved by "breaking in" a new belt, but breaking in a belt will without a doubt extend the life.

"Low Range is built into a snowmobile clutch"?????? Not sure what you mean here; especially with speeds in the 90's and sometimes 100's of miles per hour. Sleds have only one gear set(a top and a bottom) in the chain case (not counting reverse). A sled clutch system handles 5 mph the same as 90 mph.

As far as a sled have the advantage of a "cooler" belt, not hardly. The outside air temp does help "cool" the belt, however the belt and clutch still get hot to the touch.

The entire concept of the belt drive CVT relies on friction. A great deal of friction. Friction cause heat. Heat degrades belt life. This is where I think many people have no concept of how these clutches work.

 

You seem to be the "expert" on clutches and CVT's. Let me ask you this: It sound like you are saying that a snowmobile CVT does NOT have an air intake (and exhaust) for the CVT to pull in the cool (cold air in the winter) to help keep the CVT belt and clutches cool. Is that what you just said?

Just want to make sure I've got it right when I talk to the guys on the snowmobile forum?

Number two. You may want to read this:

How does the clutch system work? - Gates Snowmobile & ATV Belts

EDIT: In case you missed it in the text, I thought I would put a couple quotes from that text here to make sure you didn't miss it:

In effect, the sled is transitioning from the low range to the high range (See region C in Fig. 5.). Assuming the sled is properly geared and has sufficient horsepower, the transition from low range to high range will continue until high range is achieved and top speed is obtained.

Another example is riding in deep powder snow in a hilly area. This places heavy demands on horsepower. During the initial acceleration, the system operates as it did in the previous discussion in region A and B of Fig. 5. Similarly, the system will begin to shift toward high range (region C of Fig. 5), but the secondary pulley will quickly respond to the very high power requirement of the deep powder and/or a hill and override the primary pulley's control. The engine will remain at its maximum horsepower rpm, but the drive only transitions part way from low range to high range. The analogy is that the sled doesn't have enough power to pull "fourth gear" so it stays in "second" or "third gear."


At least I agree with you about the heat.

 

I like the heat theory, but I still stick with the low range theory.

When I am trail riding in the woods I run LOW range, I don't go faster than 20 mph because thats about as fast as a sane person would go on a machine that heavy on trail in the woods, and at 20 mph the RPM's arn't any higher than when driving at 45 mph in high range. And your machine is less prone to damage at low speeds than high speeds.

Just because you have a hard-on for not using low range, doesn't mean its not the right solution.

 

Ah Jezzz.... you just don't get it do you? I DON'T have a hard-on for riding in Low-Range WHEN REQUIRED! What part of that don't you understand?

I'll say it again, and maybe this will also sink in... Do you really think that these guys are blowing belts because they are riding around at or below the RECOMMEND SPEED IN THE MANUAL for low range... in high range? How naive can you be?

They have a 70HP machine, and they are using it... frequently. Probably in high range and low range. When they hammer the throttle, they are beyond the required low range speed in a milli-second. Some of the belts seem to be holding up, and some don't.

Maybe Polaris should have put a 70HP sticker on the tank and said this is for reference only... please don't use it, and please only use low range except for highway speeds. I bet they wouldn't sell quite so many bikes.

Let me know if you still don't understand, and I'll explain it one last time. LOL

 

if your clutch's on your snowmobile are hot to where u cannot keep your hand on them, then they are not right, i could put my hands on the clutch of my 800 polaris snowmobile and my 150hp yamaha apex and hold them their, its all in effiecency, when u start blowin belts on a sled its becuz 1.(short track).your running your sled through deep powder wide open, 2.your clutch's need alignment or they have a burr some where or 3. u climb on your sled first thing and give it hell, the belt does need to warm up some. Clutch's on a 4 wheeler are no different, maybe the guy who blew 4 belts in 200miles isnt dissapating the heat fast enough, isnt the gaurd on the popo's sealed with a vent???

 

Its not that they are riding at speeds below the recommended speed, its when they are in high and are going over logs, rocks, through mud, popping wheelies, etc from a stop and the clutch is slipping on the belt because the "leverage" is just too much for the clutch plates to grab the belt when trying to go over/through the obstacle. Low range gets rid of the leverage. And when the clutch slips, it shines/smokes the belt and creates a weak spot and thats what it takes to cause a belt to fall apart eventually.

You seem to be a stickler for "what the manual says"....... Oh, geee whiz, if you open your manual, it says to use low range when operating in rough terrain, which I do believe would include the trails in the woods, and swamps, etc.

Let me know if you still don't understand, and I'll explain it one last time.

 

Again, the starting clutch / tight belt setup will eliminate a ton of these belt issues and you can do a lot more in High with such a setup.

THe current system ALWAYS has a small amount of belt slip and heat generated at the point of initial engagement.

Hello Polaris anyone home?

 

I don't think the guys blowing belts are operating in high in rough terrain..that isn't what is smoking the belts..using high to climb obstacles,steep hills ect would be pure dumb..and wouldn't feel right to 99.9999% of people who would buy an 850. Also I don't think it is popping wheelies in high either...at least not at low speeds ie out of the hole..I can pull the front all day long in high from a stop and never smell the belt or have it slip.
I can tell you what makes mine heat/slip the belt...extended WOT in high range....on FLAT hard pack...ie a "drag pass" not even from a stop...say rolling along at 10 mph in high and nail it hold WOT up to 50 mph...that is when I smell belt.
I just got back from riding quite a few miles(~200) in some really deep nasty powdery sand down in Florida. In that deep sand it's like the machine weighs 3000 pounds...it robs some serious power..
I must say the clutches and belt held up very well..I even rode alot of it in high only averageing about 10-12mph..just to see if I could smoke the belt(yep I had a spare)..it never slipped not one time in high range in the thick sand and I never a belt smell while riding in high in the deep sand..I mean the sand was so deep that in high it would backshift and you barely could tell a difference in high range and low range engine RPMs for a given area i the deep stuff...that is also a testement to how well the clutches shift in that kind of enviroment.. BUT I never went more than half throttle in the deep sand in high range. When we would come to a stretch of asphalt/or hard pack clay road and take off like banshees I could smell a hint of belt. Basically from what I am seeing the belt doesn't like WOT operation in High..regardless of the terrain.

BTW I can appreciate you defending the Polaris PVT but IMO you are totally missing DCTs point.