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Hey guys

I'm trying to run a pull behind mower with my rhino, but I'm finding it hard to keep a semi-constant speed when running under 10 mph. Is this just a CVT thing or is there something I can do to make the belt grab tighter in Low?

Also, I can't tell a whole lot of difference between Low and High...sound like an adjustment issue or time for a new belt? I have almost 2000 miles on it.
 

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Yea 4wheel seems to help some, but I haven't tried the diff lock because of the increased effort to turn the wheel. I'm mowing 15-20 miles of rice field levees. But I'll give it a try and see if it gives me more speed control. Thanks.
 

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Hey guys

I'm trying to run a pull behind mower with my rhino, but I'm finding it hard to keep a semi-constant speed when running under 10 mph. Is this just a CVT thing or is there something I can do to make the belt grab tighter in Low?

Also, I can't tell a whole lot of difference between Low and High...sound like an adjustment issue or time for a new belt? I have almost 2000 miles on it.
This is one of the down sides of CVT's.

Yamaha belts are always "tight" unlike some other's, and the only thing low does is give lower gearing in the sub tranny. The engagement points and "tightness" would be the same.
 

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Your pulling power is not better in low over high due to the way a CVT works but please use low range for two reasons, more engine rpm for more air moving for cooler belt, and because the belt will ride a little higher in low at those slow speeds so you will have a little more belt grip again for lower belt temps.

Todd
 

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Your pulling power is not better in low over high due to the way a CVT works but please use low range for two reasons, more engine rpm for more air moving for cooler belt, and because the belt will ride a little higher in low at those slow speeds so you will have a little more belt grip again for lower belt temps.

Todd
Why exactly would there be more 'grip' when the belt is riding higher? And why would the belt be riding higher in low gear if the engine is revving higher, as it is in a lower gear? If I had a manual transmission, a lower gear would be more RPM for the same road speed, as a given.
 

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Let's use 10mph, do you think the belt would be in same place on sheaves at 10 mph in low and in high? Physically impossible

The more grip is because the fact the belt is higher so there is more spring pressure on secondary and the weights are moving up with more pressure there as well.

Even if you disagree with this, there is more rpm with more air moving so cooler so any time you are under 25 for any length of time use low range.

Todd
 

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Your pulling power is not better in low over high due to the way a CVT works...

Todd
Yes, it will. Due to the simple fact of mechanical gearing. That's kind of like saying your manual transmission truck pulls a heavy trailer better in 5th than 1st.
 

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Your pulling power is not better in low over high due to the way a CVT works...

Todd
Yes, it will. Due to the simple fact of mechanical gearing. That's kind of like saying your manual transmission truck pulls a heavy trailer better in 5th than 1st.
No it wont because in low it shifts out quicker on the clutches which is like shifting gears going, it is the beauty of the CVT. So in the end it is the same more or less.

In the end the only difference is the load on belt and engine

Kinda like having two transmissions, one manual and one automatic and they equalize.

Did a 0-40 run in low and high one time with our sheave, exact same time. Was trying to figure out why then the above came to me.

Sounds weird I am sure but it's true.
 

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Let's use 10mph, do you think the belt would be in same place on sheaves at 10 mph in low and in high? Physically impossible

The more grip is because the fact the belt is higher so there is more spring pressure on secondary and the weights are moving up with more pressure there as well.

Even if you disagree with this, there is more rpm with more air moving so cooler so any time you are under 25 for any length of time use low range.

Todd
First, let me say that I agree with running in low gear to better control the lower speed consistency, as was the subject of this thread.

The reduction in belt heat generation is arguable though. I agree that the compression force of the sheave upon the belt is increased by the secondary spring compression, which in turn is caused by the weights moving outward in the primary sheave. With that, I believe that causes more heat to be generated in the belt and not the other way around as you are suggesting. I am basing this on the assumption that there is no slippage of the belt at any time, which is the reason for Yamaha's usage of the wet clutch to disengage the motor at idle (rather than the opening of the sheaves to disengage the belt, as with the classic snowmobile CVT). The belt does not ever 'slip' but it does 'squirm' as it rounds the bend at the pulley. As it is bent it will get fatter in the cross-section, as the compressed rubber has to go somewhere. The increased pulley compression force that we are talking about squashes the rubber the other way. The heat generated in the belt is caused by deformation of the rubber, the increased deformation leads to more heat generated as the belt passes into and out of a pulley. All v-belt drives are relatively inefficient because of this squirming effect, which is similar to the heat generated by a tire as it rolls. Low air pressure leads to more deformation as the sidewalls flex further.
 

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Ok you gave me your argument. If you use high range the belt will be lower in the primary thus turning a tighter turn and in low range it comes on up the primary and is not turning as tight.

Anyway it is all a moot point, if you are going under 25mph for anything length of time use low range more air movement.

Todd
 

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Your pulling power is not better in low over high due to the way a CVT works...

Todd
Yes, it will. Due to the simple fact of mechanical gearing. That's kind of like saying your manual transmission truck pulls a heavy trailer better in 5th than 1st.
No it wont because in low it shifts out quicker on the clutches which is like shifting gears going, it is the beauty of the CVT. So in the end it is the same more or less.

In the end the only difference is the load on belt and engine

Kinda like having two transmissions, one manual and one automatic and they equalize.

Did a 0-40 run in low and high one time with our sheave, exact same time. Was trying to figure out why then the above came to me.

Sounds weird I am sure but it's true.
And why does the CVT "shift out" quicker?

Could it be that the lower gearing of low range allows the engine to accelerate the mass of the vehicle quicker and rev up faster? Could be.

The CVT reacts to sheath RPM and load. It has no ideal what range it is in. It is true that there is less load on the belt in low...but that goes right back to the mechanical advantage of low range. You could duplicate the high range belt loading in low...all you have to do is add more weight. More than would be required for the same belt loading in high.

This is simple, mechanical common sense.
 

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And why does the CVT "shift out" quicker?

Could it be that the lower gearing of low range allows the engine to accelerate the mass of the vehicle quicker and rev up faster? Could be.

.[/QUOTE]

That is exactly why it does it and why they both are equal in the end.

Let me use another way of looking at it.

Let's say low is first gear and high is second gear in the transmission

Then lets say that the belt in the bottom of the primary or near bottom is 1st gear on it and up higher is 2nd gear.

So in low gear you are in 1st and due to rpm and load the belt raises up into 2nd gear on the sheave

Now in high gear or 2nd you are starting off in second gear on the tranny but the belt stays in bottom or near bottom of sheave due to the load trying to get it going so you are in 1st in the sheave

Either scenario you are in the theoretical 3rd gear combined at the same speeds.

Nothing else can explain exact same timed runs in low or high

Again it is a moot point, if you are running 25mph and under a lot you need to use low to increase air flow.

Todd
 

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That is exactly why it does it and why they both are equal in the end. .......
It is indeed probably a moot point as far as moving about without a heavy load. However, in a different scenario where you are pulling a stump out, pulling someone out of a mud hole, or starting out on a very steep grade, the situation is rather different. There, the difference is a lot more slippage in the wet clutch when starting in high gear as compared to starting in low. I am bringing this up to show that there is indeed value to using the low range in certain situations where you cannot immediately get up to a decent rolling speed. It seems that there have been a lot more wet clutch replacement issues recently, as compared to way back when.
 

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That is exactly why it does it and why they both are equal in the end. .......
It is indeed probably a moot point as far as moving about without a heavy load. However, in a different scenario where you are pulling a stump out, pulling someone out of a mud hole, or starting out on a very steep grade, the situation is rather different. There, the difference is a lot more slippage in the wet clutch when starting in high gear as compared to starting in low. I am bringing this up to show that there is indeed value to using the low range in certain situations where you cannot immediately get up to a decent rolling speed. It seems that there have been a lot more wet clutch replacement issues recently, as compared to way back when.
Agreed, I don't think any of us arguing have said use high gear when you should be in low.

As I said lots less stress on all parts involved when in low when you should be in low and not high.

Love some forums, this hair has been split and I am out!! LOL
 

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That is exactly why it does it and why they both are equal in the end. .......
It is indeed probably a moot point as far as moving about without a heavy load. However, in a different scenario where you are pulling a stump out, pulling someone out of a mud hole, or starting out on a very steep grade, the situation is rather different. There, the difference is a lot more slippage in the wet clutch when starting in high gear as compared to starting in low. I am bringing this up to show that there is indeed value to using the low range in certain situations where you cannot immediately get up to a decent rolling speed. It seems that there have been a lot more wet clutch replacement issues recently, as compared to way back when.
Agreed, I don't think any of us arguing have said use high gear when you should be in low.

As I said lots less stress on all parts involved when in low when you should be in low and not high.

Love some forums, this hair has been split and I am out!! LOL
Sorry for dragging this out but my issue here has to do with simplistic statements such as "That is exactly why it does it and why they both are equal in the end". This certainly could lead someone to take it on faith that there is no difference at all, eh?
 

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It is indeed probably a moot point as far as moving about without a heavy load. However, in a different scenario where you are pulling a stump out, pulling someone out of a mud hole, or starting out on a very steep grade, the situation is rather different. There, the difference is a lot more slippage in the wet clutch when starting in high gear as compared to starting in low. I am bringing this up to show that there is indeed value to using the low range in certain situations where you cannot immediately get up to a decent rolling speed. It seems that there have been a lot more wet clutch replacement issues recently, as compared to way back when.
Agreed, I don't think any of us arguing have said use high gear when you should be in low.

As I said lots less stress on all parts involved when in low when you should be in low and not high.

Love some forums, this hair has been split and I am out!! LOL
Sorry for dragging this out but my issue here has to do with simplistic statements such as "That is exactly why it does it and why they both are equal in the end". This certainly could lead someone to take it on faith that there is no difference at all, eh?
Agreed, I am guilty of making blanket statements.
 

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Thank you for hearing me out Todd. I do believe that I have learned something from your explanations of CVT behaviour. With that, perhaps we are both done with this subject, LOL.
 

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Look...the CVT has a ratio range. High or low in the sub tranny does not effect this range ( of the CVT ).

Being in low gives the engine more "leverage" over any load it must pull, at the cost of speed. This activity with most loads probably allows the CVT to shift pretty quickly as you stated. But rest assured that if you could load it enough in low range, it would shift in an identical manner to what the average run would do in high ( with a lighter load ).

It may be impossible to load a Rhino this much...to truly test out the reduction in low, since most vehicles are limited by traction and/or parts strength.

But if you could somehow find traction and put enough load on the machine, you would see that at some point, low range would be able to yank it into motion, when high would do nothing but slip the clutch, and not even turn the primary sheave.
So your statement that "...pulling power is not better in low..." is simply false.

This is a simple mechanical concept that is at work in any type of vehicle that has a transmission of any kind. I don't know how to explain it any better than i have.
 
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