Why ballance clutches???

[THRILL_SEEKER]

Just wondering why we should ballance our clutch? What will make a clutch go out of ballance?

Just so I am clear, the clutches are ballanced from the factor with what i would assume would be top of the line technolodgy correct? I have been told that this process is done with no weights or springs in the clutch.

I know i am not the only one the has weighed the weights individually and found them to be off by as much as a gram.

So if we can assume the clutch is ballanced from the factory and we ballance the weights ourselves, shouldn't the clutch be ballanced? And if it is then ballanced, what would make it become unballanced?

I only wonder this because if the factory clutch when assembled with springs and weights is not ballanced(because of the weights being as much as a gram different from each other) it must not make that much difference to the factories specs and therefore not make that much of a difference.

Not trying to ramble just had a thought and was wondering what you all thought.

 

[tdblakes]

Just wondering why we should ballance our clutch? What will make a clutch go out of ballance?

Just so I am clear, the clutches are ballanced from the factor with what i would assume would be top of the line technolodgy correct? I have been told that this process is done with no weights or springs in the clutch.

I know i am not the only one the has weighed the weights individually and found them to be off by as much as a gram.

So if we can assume the clutch is ballanced from the factory and we ballance the weights ourselves, shouldn't the clutch be ballanced? And if it is then ballanced, what would make it become unballanced?

I only wonder this because if the factory clutch when assembled with springs and weights is not ballanced(because of the weights being as much as a gram different from each other) it must not make that much difference to the factories specs and therefore not make that much of a difference.

Not trying to ramble just had a thought and was wondering what you all thought.

You balance your clutch for the same reason you balance your wheels on your truck, vibration. An unbalanced clutch will create unwanted vibrations and since it is connected to the crank, this unwanted force can damage or bend vital components of your motor. It would be hard on bearings that are not designed to support that kind of load and also fatigue the shaft because it will be flexing up and down as it rotates. Also, this vibration creates resistance to rotation bringing RPMs down. Imagine a fan that is missing one rotor, it would vibrate like crazy and bounce all around and rotate slower. Put that blade back on and it is smooth and rotates fast.

The + or - one gram on the weights must not be a significant enough change in rotating mass to throw the clutch out of balance, the crank must be strong enough to handle and maintain its alignment. But I bet if you could spin your motor at alot higher RPM it would really throw things outa wack. There is a resonant frequency (very bad) associated with each vibration, so I would assume that the amount of weight and distance it is off center of rotation is not enough to significantly affect the clutch rotation and come anywhere near resonant frequency.

If you balance your weights properly it would make your clutch even smoother, but for them to have each weight to say within a + or - 0.01g tolerance would make them extremely expensive to produce and more expensive for us to buy. Since it must not significantly affect the balance of the clutch, industries hold the tolerance that they can while maintaining desired performance.

 

[Clarke673]

we balance our car tires and they don't spend 8000+ RPMS.

 

[Ron]

You are on the right track. Unless you adjust for belt side clearance your clutch is "close enough" from the factory. They rarely get them perfect though & balancing the weights is a good idea-it keeps the tolerance's closer.

 

[tdblakes]

I guess to build on this thread... the reason they are not the same weight is due to inconsistant material densities right? Not physical dimensions of the weight itself? Has anyone measured any weights they found to be different to see if they had different dimensions using a calipers or micrometer? If you wanted to mill them slightly, where would you take the weight off? I know the shape of the weights plays a big part in the clutch performance, so you would want to take it off closest to where you put the pin through the weight? On the bottom or equally on each side surface? If you wanted to achieve any kind of tight tolerance I would think this would mean a trip to a machine shop and not any at home in the garage type of ordeal unless you have the proper tooling... So who has done this?

Wouldn't it be easier to just have an entire clutch balanced with the weights in it already rather than balance each piece individually?

 

[EricW]

Any of you clutch or engineering guru's know the calculations for how much increase there is in a say 2 gram difference in clutch balance static (sitting on the bench) compared to the same 2 grams at 8000 rpm. Seems like I saw it once and it was amazing how the centrifical force changed 2 grams to like 12 pounds or something at max rpm. Just curious, but I remember after seeing the numbers I was a believer in attaining good clutch balance. EW

 

[tdblakes]

Any of you clutch or engineering guru's know the calculations for how much increase there is in a say 2 gram difference in clutch balance static (sitting on the bench) compared to the same 2 grams at 8000 rpm. Seems like I saw it once and it was amazing how the centrifical force changed 2 grams to like 12 pounds or something at max rpm. Just curious, but I remember after seeing the numbers I was a believer in attaining good clutch balance. EW

Yea I definately think its a good idea when done right. I'm sure it would make a huge difference in how smooth everything feels and how efficient your clutching is.

 

[MacDawg productions]

Just wondering why we should ballance our clutch? What will make a clutch go out of ballance?

Just so I am clear, the clutches are ballanced from the factor with what i would assume would be top of the line technolodgy correct? I have been told that this process is done with no weights or springs in the clutch.

I know i am not the only one the has weighed the weights individually and found them to be off by as much as a gram.

So if we can assume the clutch is ballanced from the factory and we ballance the weights ourselves, shouldn't the clutch be ballanced? And if it is then ballanced, what would make it become unballanced?

I only wonder this because if the factory clutch when assembled with springs and weights is not ballanced(because of the weights being as much as a gram different from each other) it must not make that much difference to the factories specs and therefore not make that much of a difference.

Not trying to ramble just had a thought and was wondering what you all thought.

I'm wondering this as well.I understand the importance of having a balanced clutch, and it's side effects if it isn't, but what is entailed in balancing a clutch when you get it serviced at a shop? Do they just pull the clutch off, clean it, blow it out with compressed air, inspect your bushings, put new weights on and that's it? Something that you can easily do at home once a season?

 

[Kraven]

FACTORY QUALITY CONTROL, or lack there-of

TS,

1) My 2002 EDGE-X 800 Clutch, sent it out to SLP when close to new, WAS way off!! approx 8-9 lightening holes drilled into it. Upon re-installation, the sled ran noticeably smoother, you could feel the difference in the bars. One has to wonder if that wasn't at least in part, the cause attributing to the crank failures. I ran my 2002 EDGE-X 800 for 6400+ trouble-free miles, .0025" run-out when I sold it.

2) Sent out the 2003 XC 800 clutch from my bud's sled, 1 lightening hole drilled

3) Also sent out the primary from my 2001 EDGE-X 600, only 1 lightening hole drilled

So much for pride in workmanship.


BTW, SLP balances the clutches as a complete unit, so you still need to be watchful of aligning the "X" s when re-indexing/re-shimming the spyder.

INDY Dan and MICRO-BELMONT balance the components (spyder, sheaves) INDIVIDUALLY, so no further need to align the "X"s

Price diff, SLP= $35.00, MICRO-BELMONT$75-$85 last time I checked.

Hope this helps!

Just wondering why we should ballance our clutch? What will make a clutch go out of ballance?

Just so I am clear, the clutches are ballanced from the factor with what i would assume would be top of the line technolodgy correct? I have been told that this process is done with no weights or springs in the clutch.

I know i am not the only one the has weighed the weights individually and found them to be off by as much as a gram.

So if we can assume the clutch is ballanced from the factory and we ballance the weights ourselves, shouldn't the clutch be ballanced? And if it is then ballanced, what would make it become unballanced?

I only wonder this because if the factory clutch when assembled with springs and weights is not ballanced(because of the weights being as much as a gram different from each other) it must not make that much difference to the factories specs and therefore not make that much of a difference.

Not trying to ramble just had a thought and was wondering what you all thought.

 

[MacDawg productions]

Very interesting.....

 

[chumbilly1]

I found my 10 64 polaris weights were off by .3 grams, I used a grinder and took material off of each side as evenly as possible by hand, and then checked them against each other with my calipers. I took them down to 63- and I feel that they are better balanced than they were stock. I understand that you want to remove material from both sides as to not affect the shift characteristics of the weights, only the mass. For 50$ slp clutch balancing seems like a bargain. I think I will send mine down over the off season and see how close the boys in MN got it.

 

[skis_n_skid]

Any of you clutch or engineering guru's know the calculations for how much increase there is in a say 2 gram difference in clutch balance static (sitting on the bench) compared to the same 2 grams at 8000 rpm. Seems like I saw it once and it was amazing how the centrifical force changed 2 grams to like 12 pounds or something at max rpm. Just curious, but I remember after seeing the numbers I was a believer in attaining good clutch balance. EW

The amount of affect that centrifugal force has on X amount of mass depends greatly on where the mass is located relative to the center of rotation, and also how far away it is from the point of support (PTO shaft). The farther out from the center, and/or the father away from the motor the extra weight is, the more affect centrifugal force will have on it due to increased leverage moment (longer leverage arm).

For example, if you added an extra gram of weight to one of the bolts that hold the face cover on, it would throw the balance WAY off. Extra weight that far from the point of support and that far from the center of rotation is going to be affected a lot more by centrifugal force than having an extra gram of weight closer to the center of rotation and closer to the point of support (like where the bulk of the mass of the weights is located).

For that reason, even if you make the weights all weigh the exact same amount, they will not necessarily be balanced. Just weighing the same amount isn't enough to make them balanced. One could still have slightly more mass on the big end while another has slightly more on the small end. So even though they weight the same, they will be affected by centrifugal force differently. To be truly balanced, they would all have to have the same balance point (the point at which the weight would be balanced on the head of a pin).

 

[THRILL_SEEKER]

ok so i get the whole cost thing to have tight tolerences for clutch ballence, but you mean to tell me that places like slp and the fellows you listed on here(indydan i think was one) can ballance them better then a big company for less then $100? I would pay $200 more for my sled to have the clutch ballanced from the factory, considering i shelled out over 10k for my sled, whats another couple hundo to have it right.

The other thing that wonders me is once you have the clutch ballanced, why would you need to ever have it done again? How can it become out of ballance when its all bolted togeather?

i understand having your tires ballanced every once in a while but i think that is a diffrent issue. tires are rubber and are wearing in dif. places and so on so i can see how they can get out of wack, but i just dont see how an alluminum clutch bolted togeather can get out of ballance?

 

[mtnclimber19]

I guess to build on this thread... the reason they are not the same weight is due to inconsistant material densities right? Not physical dimensions of the weight itself? Has anyone measured any weights they found to be different to see if they had different dimensions using a calipers or micrometer? If you wanted to mill them slightly, where would you take the weight off? I know the shape of the weights plays a big part in the clutch performance, so you would want to take it off closest to where you put the pin through the weight? On the bottom or equally on each side surface? If you wanted to achieve any kind of tight tolerance I would think this would mean a trip to a machine shop and not any at home in the garage type of ordeal unless you have the proper tooling... So who has done this?

Wouldn't it be easier to just have an entire clutch balanced with the weights in it already rather than balance each piece individually?

Then the clutch would be set to the imperfections of the weights and those weights would always have to be put in the same spot on the clutch. And if you changed wieghts you would have to rebalance the clutch all over again. Thats why it is easier to balance the clutch with no weights or springs in it.

 

[Pownar]

You balance your clutch for the same reason you balance your wheels on your truck, vibration. An unbalanced clutch will create unwanted vibrations and since it is connected to the crank, this unwanted force can damage or bend vital components of your motor. It would be hard on bearings that are not designed to support that kind of load and also fatigue the shaft because it will be flexing up and down as it rotates. Also, this vibration creates resistance to rotation bringing RPMs down. Imagine a fan that is missing one rotor, it would vibrate like crazy and bounce all around and rotate slower. Put that blade back on and it is smooth and rotates fast.

The + or - one gram on the weights must not be a significant enough change in rotating mass to throw the clutch out of balance, the crank must be strong enough to handle and maintain its alignment. But I bet if you could spin your motor at alot higher RPM it would really throw things outa wack. There is a resonant frequency (very bad) associated with each vibration, so I would assume that the amount of weight and distance it is off center of rotation is not enough to significantly affect the clutch rotation and come anywhere near resonant frequency.

If you balance your weights properly it would make your clutch even smoother, but for them to have each weight to say within a + or - 0.01g tolerance would make them extremely expensive to produce and more expensive for us to buy. Since it must not significantly affect the balance of the clutch, industries hold the tolerance that they can while maintaining desired performance.

In my experiences, the + or - one gram is very significant and is almost not runnable.

 

[evandaigneault]

straight from the factory the primary is usually off. Whenever i get a new clutch i have it balanced brand new out of the box and they have always been off. Some have been close but i have never seen one that hasnt needed some balancing brand new.


I attribute this to mass production of the p85

Evan

 

[Kraven]

BALANCING AS A COMPLETE UNIT vs. Individually

Thrill seeker,

Regarding re-balancing, if the clutch is balanced as an assembly at first and then you later change weights, let's say from a 10 series to a MTX style, the shoulder height is different and would require re-shimming the spyder which then MOVES the location of the spyder, and since the clutch was balanced as an assembly, it then becomes a different program.

Thus, in that case the INDIVIDUAL balancing would be the preferred method.

For the guys that won't mess with their clutching after the initial set-up, the $35.00 balancing job will probably suffice.

Hope this helps

ok so i get the whole cost thing to have tight tolerences for clutch ballence, but you mean to tell me that places like slp and the fellows you listed on here(indydan i think was one) can ballance them better then a big company for less then $100? I would pay $200 more for my sled to have the clutch ballanced from the factory, considering i shelled out over 10k for my sled, whats another couple hundo to have it right.

The other thing that wonders me is once you have the clutch ballanced, why would you need to ever have it done again? How can it become out of ballance when its all bolted togeather?

i understand having your tires ballanced every once in a while but i think that is a diffrent issue. tires are rubber and are wearing in dif. places and so on so i can see how they can get out of wack, but i just dont see how an alluminum clutch bolted togeather can get out of ballance?

 

[markoo]

You can't compare balancing your tires to balancing a clutch. If you buy a new car the tires come balanced. you don't have to rebalance them. If your clutch need to be balanced when it is new then we are getting a crappy product. I can see a clutch with 4000 miles on it might need to be checked but it should not go out of balance with out losing aluminium. 10 or 15 years ago we could get 5000 miles on our clutch with out touching them. now guys are rebuilding and balancing them all the time. I think someone should start producing a better product.

 

[evandaigneault]

You can't compare balancing your tires to balancing a clutch. If you buy a new car the tires come balanced. you don't have to rebalance them. If your clutch need to be balanced when it is new then we are getting a crappy product. I can see a clutch with 4000 miles on it might need to be checked but it should not go out of balance with out losing aluminium. 10 or 15 years ago we could get 5000 miles on our clutch with out touching them. now guys are rebuilding and balancing them all the time. I think someone should start producing a better product.

10-15 years ago stock sled werent making 155 horse but the primary clutches have remained basically the same. Just because you CAN get 5000 miles out of a clutch doesnt mean that you SHOULD. To maintain peak performance you need to balance and rebuild your clutch every 1500 miles at least in my opinion on the newer 800's.

Evan

 

[catmanm8]

After research, I have found out the factories use a dual plane dynamic (spin) computerized balancer...it's cost is approx half a million dollars...one company spins it 3 times 1 to find out where it's off 2 times to validate....some shops are using static balancers (bubble).. some spin by hand and drill the low spot.....

Are we to believe small aftermarket companies have made this investment in tooling.??.and just because there were holes drilled in it, it was off and now better?? It turns into an opinion that we can't prove or disprove...what a way to make a buck....

Some things to think about....some say mass production is bad....but with CNC machines I think things are pretty close....just some thoughts...