In low range mine hits the rev limiter at 41-42 mph.

 

I stopped pressing the gas at 38 in low. I know the engine is tough, but I prefer to either stay under 33 or stop and shift.

Ever wonder why the 700 can tow more than the 650? It is because of the low gear ratio on their low range. They can't go very fast in low.

Ever wonder why 660 owners have so much problems backing up in the mud? Their reverse gear is to high to give them any tire turning torque and the reverse is limited with no override.

Yeah, we need to shift to low, but life is not any greener on the other side of the fence either.

 

This might be a stupid question, but I'm asking because I don't know. I see my sons race, they get on the gas, wheelie, spin the tires and as soon as they cross the line they let off the gas. You can hear the wine of the engine brake. How much wear does this put on the belt, if any. I see this all the time, even riding, going fast and letting off, the bike nose dives. I know it brakes the engine, but this has to put pressure on belt when the tires are turning 40 miles an hour and the brake is applied to the engine, the belt is the go between isn't it?

I agree with Kawasaki when they say we should ride in low all we can, (my rule of thumb is 30 mph), because in low at say 5,000 rpm, the belt would be in the middle of both clutches, one half open, one half shut, so there would be about 10 inches (a guess) of belt belt being gripped by the front clutch and the same by the back. If you were in high, at the same speed, the front clutch would be open (small) and the rear closed (big). they would be gripping the same amount of belt 20 inches, but the front clutch might only be gripping 7 inches of belt and the rear 13. The front clutch (primary) does most of the work, it has to take the torque of the engine and grip the belt enough to turn the tires, bigger tires more grip required. By being in low gear all you can, you are putting more belt in the front clutch (primary) to be gripped, therefore less slippage. Does this make any sense?

Also I haven't heard anyone talk about cleaning their clutches, anytime you have your clutch cover off, take your belt off and wipe your clutches and belt down, we use dry gas, don't handle your belt with your bare hands, any oil on the belt or clutches isn't good. I remember at one pull this year, winning by 3 inches over three other bikes, (727 and 770 grizzes, four bikes all within a foot of each other) and it was probably because we cleaned our clutches between every pull, it makes a difference.

We also reuse our old belts, if the guys were going mudding, we put on an old belt, you lose some top end, but at $90.00 a belt, why ruin a new belt if you know your going to be in some tough places. Clean your clutches before putting your new belt back on, a ten minute job, time well spent.

My .02, sorry so long, I wish I could explain what I want to in a few words without thinking people won't understand what I'm trying to say.

 

that makes sense to ride in low under 30 it sounds like. I was just off I guess, I kept envisioning 4-LOW ranges on my past 4wd vehicles, and how short the gear ratio was and limited the speed was. Sounds like this low mode is a little taller than I was envisioning.

 

There is a certain amount of slippage in belts , all belts have it , that is why there are so many configurations of them, all for the purpose of defeating as much slippage and heat as possible. Slippage creates heat, and loss of power. The heat difference one of my friends who is a mechanic and drives a pole said can be as much as 160 deg. f. between low and high. The heat from slippage alone can kill a belt, this heat is olso tranfered to motor. Its a problem all belt drives have, some handle the problem better then others.
Shotgun is right the mechanical advantage of the size of the clutches is a big factor in the amount of grip available on the belt, loading and unloading with that much power must create lots of slippage / wear. driving in low gear gives you power to pull machine, less slippage on belt.

 

Shotgun, I 'm sure engine braking contributes to belt wear, but I do not believe it is nearly as significant as some of the other things that we do to the belt. The engine braking never applies as much yank to the belt as the engine does when we apply 633 cc of double thump.

I am completely unfamiliar with your cleaning concept. Every time I see the pulleys, they shine where the belt is in contact.. The belt has some dust embedded in the surface.
I get the dust out of the cover and stuff whenever I'm in there to keep it from building up and causing airflow problems. You said wiping the belt and pulley with gas helps win races. I'm just not sure what good it does for the recreational rider.

Roscoe, don't we produce less belt heat now that we have black springs? I have not noticed nearly as much heat on my cvt cover and outlet as it did with the old spring. Seems logical less slippage makes less heat. Almost all the cvt heat comes from the belt. The ribs on top and bottom are for heat transfer to keep it cool. I have a thermocouple, I wish I had taken some data.

Oh, well. I ride for fun not for science experiements.

 

This topic is constantly rehashed on the forum. My opinion on this matter is that the belt on a CVT drive system is a wearable item. It's like brakes on a car. If you take it easy and baby your brakes you can get 70K miles out of them. If you run your car hard and dive hard into curves and make fast stops, etc., you'll only get 30K miles out of your brakes. The belt on the P650 (and any other belt driven quad for that matter) is the same way. If your major concern is belt life you should run in low as much as possible and be very careful with it. If however your major concern is hard riding and pushing yourself and your machine for all you can the belt life issue won't be that important to you. Granted, I've heard more issues with belts on the P650 than any other quad. But, I think a major factor is the amount of torque the 650 is putting out. The traditional belt setup may not be enough to handle this. I have 1100 miles on my 650. I run in high gear 98% of the time. I only shift into low if I am hauling something or going over some very rough technical or tight terrain. Otherwise I am running in high regardless of the speed but I will say that I would rarely be below 15 MPH and usually at 40 plus MPH. I just received my black spring from EPI but have not installed yet. I will look at my belt wear closely at that time and report as to what condition it is in. I had the belt adjusted once at about 30 hours and periodically remove the cover and blow out the dust, etc. One key issue is don't sit with your bike in gear giving it the gas and not moving ie, trying to pull out of a deep rut or something. This causes belt slippage and creates heat. I saw a guy do that on a Polaris once and it got so hot that it melted the side cover and of course ruined the belt. If the wheels are turning and the belt can turn freely with the pulleys this won't happen.

Same as SHOTGUN said - sorry for the long post but there are so many factors involved with this issue it's hard to keep it short. I'm sure a lot of people will disagree with my opinion and that's what makes horse races.[img]i/expressions/face-icon-small-happy.gif[/img]

 

If the aftermarket gets off their butts and gives us a belt for $30-$40, we'll all just throw a new one on every year. The belt wear problem will become a non-issue.

 

Let me clarify some of the things I said. First I agree with Kawasaki that the belts will last longer if we ride in low, I explained why, I don't agree that we should <U>have to ride in low</U> to save the belt. I didn't buy mine to go slow, I open her up when ever possible, therefore I'm in high most of the time while riding, if it's slow hard going I ride in low, other than that it's HIGH.

Nyroc, About cleaning the clutches and belt, sometimes I get carried away and think everyone ATV pulls. The instance I was talking about where we won by 3 inches was a pull not a race. If anyone Atv pulls you know that the slippage under pressure "glazes the belt and clutches", they get really shinny, almost like a belt that is burnt from slipping. Maybe this is a non factor if you just ride, I don't know. I would still recommend cleaning them if your in there, if there is belt dust in your cover there probley is some glazing. To get rid of the glaze we use dry gas, DO NOT USE GAS, it is CALLED isopropal, not sure of the spelling. If you don't clean the clutches when they are glazed the slippage is more and wear is more and it creates more heat.

We put a new belt on for every pull and clean our clutches between each class, we then use the old belt for rideing.

I wish the belts only cost $30 - $40 also, wouldn't that help. I also agree about the heat, maybe the cooling fan some how needs to cool the belt also. I think there are more of us working on the problem than at Kawasaki.

Keep the idea's coming. Almost every post on here has good infro.

Thanks for the infro on the engine brakeing, always wondered, but never seen a post on it.

See ya!

 

Nyroc
Not sure what advantages the black spring gives , never gave it any thought. but if it works use it. Removing the spacer, spacers or whatever is needed to change the deflection , creates the proper width of sheave"making it fit the belt is the purpose of this" and in doing so it shortens the belt length. This is what is needed to get the necessary friction for running the drive wheels, cant have floppy belt slipping and creating heat. if the black spring is creating tension to hold the sheaves halves together " self adjusting spacers? " then it is trying to defeat the slipping problem.
On a sled the weights are trying to force the drive together putting friction on belt, the spring is trying to hold them apart, the spring is designed that the weights will overpower it at set rpms.. the driven sheave is together , held by a spring, and the belt is trying to force it apart.
maybe you can tell me what the black spring is doing on kawi , i honestly didn't pay much attention to the threads envolving it.