good info
DRIVE CLUTCH BALANCING DIFFERENCES
- Thread starter indydan
- Start date
J
You could have balanced all of them with the time it took you to type thatI had the $30 balance job. Works great. Watched him do it, took a whole 5 minutes.
snowstar im in ogden also who did yours i need mine done
Just to add to the clutch balancing confusion...
Now there's a good question...any thoughts from the crank pro's?or, does the lack of permanent attatchment to the clutch nullify the belt as a factor of balance?
Curt.... I would imagine that there are some "BAD" belts out there that have manufacturing defects in them or have a heavy section to them... For the most part, IMO, on the 3211115 belts and other high dollar, cut or ground belts... most are in mfg tollerance and are pretty neutral.
Without a direct attachment to a fixed location on the clutches, the belt, IMO would have to be looked at as seperate from the clutch in regards to balance. If the clutch is balanced and you still have a problem you feel is related to balance... try another belt and see if that fixes your issue.
The best bet is to make the Primary clutch as good as you can get it... a "baseline" if you will... Then, As RON pointed out in his very thourough Thread on the P-85... make sure that the wieghts are the same as each other...
There are many ways to debate this topic... and get lost in the details...
I have seen very poor factory balance jobs on clutches... VERY poor... this coupled with poorly shimmed spiders and even loose nuts/bolts...
leads me to believe that IF you want reliable performance from your sled, no matter of weather or not you believe that the factory should have to deliver a perfect clutch... you should have your clutch properly setup...
Have a look at this post to see that it is not just simple job to make the best of this crucial "primary link" in the performance of your snomobile.
http://www.snowest.com/forum/showthread.php?t=87640
On a balance job... there are good ones and not so good... some only need a simple balance.. other needs a complete remanufacture and blueprinting of the clutch which would include re-machining/truing the shieve faces and rebuilding the spider.
Having the correct side clearance on the belt in the primary... you need to shim the spider... which requires proper expensive tools (over $100 worth).... this also has a big effect on clutch performance.
When you are pricing this out... compare apples to apples... if your clutch is "loose", the pin bores are egg shaped, the faces are grooved/worn etc... all the ballancing in the world is not going to help the performance...
Just my 2 centavos.
Heck... If I get the new Team-Tied secondaryclutch I am going to get that sukka ballanced after I get the helix specs dialed in!!
Without a direct attachment to a fixed location on the clutches, the belt, IMO would have to be looked at as seperate from the clutch in regards to balance. If the clutch is balanced and you still have a problem you feel is related to balance... try another belt and see if that fixes your issue.
The best bet is to make the Primary clutch as good as you can get it... a "baseline" if you will... Then, As RON pointed out in his very thourough Thread on the P-85... make sure that the wieghts are the same as each other...
There are many ways to debate this topic... and get lost in the details...
I have seen very poor factory balance jobs on clutches... VERY poor... this coupled with poorly shimmed spiders and even loose nuts/bolts...
leads me to believe that IF you want reliable performance from your sled, no matter of weather or not you believe that the factory should have to deliver a perfect clutch... you should have your clutch properly setup...
Have a look at this post to see that it is not just simple job to make the best of this crucial "primary link" in the performance of your snomobile.
http://www.snowest.com/forum/showthread.php?t=87640
On a balance job... there are good ones and not so good... some only need a simple balance.. other needs a complete remanufacture and blueprinting of the clutch which would include re-machining/truing the shieve faces and rebuilding the spider.
Having the correct side clearance on the belt in the primary... you need to shim the spider... which requires proper expensive tools (over $100 worth).... this also has a big effect on clutch performance.
When you are pricing this out... compare apples to apples... if your clutch is "loose", the pin bores are egg shaped, the faces are grooved/worn etc... all the ballancing in the world is not going to help the performance...
Just my 2 centavos.
Heck... If I get the new Team-Tied secondaryclutch I am going to get that sukka ballanced after I get the helix specs dialed in!!
Re read the first post in the thread carfully and come to your own conclusion.
R
indydan: can you explain the difference between a spin balance and a static or bubble balance? Which do you use and why? Can you give us pro and cons?
I'm asking because earlier this year I sent the clutch off of my 09 Assault to be balanced, assuming it would be spin balanced. Less than 5 hours of ride time later, the clutch cracked and broke in half right between the sheaves. The fixed sheave spun on the crank, welded itself to it, and ruined the crank end. Ended up being a spendy fix.
I'm no guru and don't know what happened first or what caused this to happen, but later found out that the clutch had been bubble balanced. I'm suspicious of the "balancing" having caused the problem. Your thoughts please?
PS. I originally sent to clutch off because of a broken bolt in one of the towers. Hadn't had any problems with the clutch, no reason to suspect it wasn't balanced. Just figured might as well get it balanced while it was there.
I'm asking because earlier this year I sent the clutch off of my 09 Assault to be balanced, assuming it would be spin balanced. Less than 5 hours of ride time later, the clutch cracked and broke in half right between the sheaves. The fixed sheave spun on the crank, welded itself to it, and ruined the crank end. Ended up being a spendy fix.
I'm no guru and don't know what happened first or what caused this to happen, but later found out that the clutch had been bubble balanced. I'm suspicious of the "balancing" having caused the problem. Your thoughts please?
PS. I originally sent to clutch off because of a broken bolt in one of the towers. Hadn't had any problems with the clutch, no reason to suspect it wasn't balanced. Just figured might as well get it balanced while it was there.
indy nice write up. always get what you pay for. id be leary of a thirty dollar clutch balance. i personaly like quality work and dont mind paying for such. not everyone is willing to pay for time spent, always wanting to cheap out. sounds like your a guy that does things right the first time,nothing wrong with wanting to be paid.
C
All of the shops balancing clutches out there.....step up to the plate...what machine are you balancing with....make and model...would love to know what we are paying for....the customer deserves to know.....
B
Can someone please explain to me how solid pieces of aluminum and steel become "out of balance"? I can spin a round aluminum disk on my desk for the next fifty years and nothing is going to happen to it to make the metal flow to where it would be out of balance, correct? I understand if the weights wear into the spider that that would cut away aluminum, but other than that, balance your weights and rebuild your clutch as necessary.....If your spider is worn you really need a new clutch anyway as that is a stress scribe for fractures, and I don't think I want to risk my leg and berries over a clutch coming apart at 8000 rpm. Come on guys. I'm as much a stickler for clutch maintenance as anybody. But, please, explain to me how my sheaves, spider, and cover become "unbalanced" from normal use. FYI we just hung an old, shot, filthy primary on our bubble balancer in the shop and it came out perfect. For shlits and grins we changed one of the weights and hung it again with 2 grams more on one leg. Guess what? Perfect balance again. Threw some nuts and bolts on it...same thing...perfect. A clutch is not big enough in diameter for a bubble balancer made for a tire. A rotating tire balancer also is NOT accurate enough to read something this small in diameter correctly. For all you that still want this done....Send me your clutches, I'll drill a couple holes in them, you can come look at them hanging perfectly on my bubble balancer, and you can give me $20......And guys that are charging for this "service" in the real world, what kind of machine are you using?
C
Ouch...:face-icon-small-dis...this got quiet quick.....HMMMMMM???
Easy answer... many different parts... none of which are fixed to each other.
Also... the factory balance and assembly leaves a LOT to be desired... includes ALL brands.
If you truly maintain your clutches... you will need to shim the primary for the proper belt side clearance with the weights you are going to use. Change the weights and you also can change this....
Bubble balancers are DANGEROUS on such a large shifting mass at 8000+ RPM...IMO... for what that is worth.
What is your background in rotating assemblies... a sincere question?
I have personally had a clutch on a 700 CFi that was indexed incorrectly upon shimming for belt clearance and it shook the sled VIOLENTLY!! Direct experience.
In a comparison... a tiny, light, compressor wheel that gets nicked on a turbo can cause the thing to come apart catastrophically... all in less than 3" diameter and very little mass.
Also... the factory balance and assembly leaves a LOT to be desired... includes ALL brands.
If you truly maintain your clutches... you will need to shim the primary for the proper belt side clearance with the weights you are going to use. Change the weights and you also can change this....
Bubble balancers are DANGEROUS on such a large shifting mass at 8000+ RPM...IMO... for what that is worth.
What is your background in rotating assemblies... a sincere question?
I have personally had a clutch on a 700 CFi that was indexed incorrectly upon shimming for belt clearance and it shook the sled VIOLENTLY!! Direct experience.
In a comparison... a tiny, light, compressor wheel that gets nicked on a turbo can cause the thing to come apart catastrophically... all in less than 3" diameter and very little mass.
B
Experiance....
Does building balanced V8 drag motors with 3.0-4.5 inch strokes count? I also worked in a few automotive shops that did tire balancing...probably balanced a thousand tires on rotating dynamic balancers. Also worked with bubble balancers and wheel truing machines. I have also built and balanced driveshafts, balanced weights, connecting rods, and pistons. What you say is most definately true-that a smaller diameter rotating assembly does get thrown out of balance with way less actual damage or difference, just look at a driveshaft. But, that is my point. None of the typical balancing processes that the average guy has access to are near accurate enough to balance a clutch properly. And the parts in a clutch are not fixed together, but they sure don't rotate around each other to different indexes under use. As asked previously, "What do all the shops charging for this service use to balance clutches?" Simple question, simple answer I would think.:face-icon-small-hap
Does building balanced V8 drag motors with 3.0-4.5 inch strokes count? I also worked in a few automotive shops that did tire balancing...probably balanced a thousand tires on rotating dynamic balancers. Also worked with bubble balancers and wheel truing machines. I have also built and balanced driveshafts, balanced weights, connecting rods, and pistons. What you say is most definately true-that a smaller diameter rotating assembly does get thrown out of balance with way less actual damage or difference, just look at a driveshaft. But, that is my point. None of the typical balancing processes that the average guy has access to are near accurate enough to balance a clutch properly. And the parts in a clutch are not fixed together, but they sure don't rotate around each other to different indexes under use. As asked previously, "What do all the shops charging for this service use to balance clutches?" Simple question, simple answer I would think.:face-icon-small-hap
Burndown,
I guess I AM missing your point.
Is it
1) Balancing a drive clutch, other than what is done a the factory, is NOT necessary in your opoinion?
2) You don't believe that a balanced clutch will operate more smoothly?
3) You simply want to find out what machinery is being used?
IndySpecialties may chime in here on #3... If you want an answer from others that balance clutches (SLP, Power Addiction, Speedwerks, Cutlers, etc) you will need to call them. I look forward to the results posted up here on what you find out from them.
I guess I AM missing your point.
Is it
1) Balancing a drive clutch, other than what is done a the factory, is NOT necessary in your opoinion?
2) You don't believe that a balanced clutch will operate more smoothly?
3) You simply want to find out what machinery is being used?
IndySpecialties may chime in here on #3... If you want an answer from others that balance clutches (SLP, Power Addiction, Speedwerks, Cutlers, etc) you will need to call them. I look forward to the results posted up here on what you find out from them.
C
The question seems to be...shops that charge our loyal snowest forum friends should not be afraid to tell us what machines they use to balance the clutches we send to them...I have PM'd and called some.....no answer or they beat around the bush.....a major clutch manufacturer told me they use a dual plane comp unit that cost approx $300,000....very accurate....is that cost effective for a speed shop or dealer to have? how many years would it take to be profitable...
If an empty clutch is balanced on this when new, how does it change? Can a small speed shop afford the proper equipment to do this with more accuracy than the manufacturer?
If it is an out of balance problem from shimming, then it is the techs fault...ps why are you shimming for belt clearance? I know it is what people do, but did you ever think about what removing shims does to belt side force and shift force at any given shift point....it reduces both...the weights are tucked...there are better ways to set neuteral side clearance that don't reduce shift/side force....twin motors with good torque don't like this...mountain sleds need belt side force because of the load going in the steep and deep...
If the clutch is out of balance from wear, the main core is probably junk anyway...ie sharp cuts from weights in the spider or grooved sheaves....
Blind faith at the cost of performance and money = too common...when some one questions the norm with fact they will be bashed....even by the super moderator... I brought this up a month ago...then Indy Dan did...now I will be bashed probably instead of...Hmmm ...
I welcome clutch tuning/rebuilding debate....I do have experience in this subject...:fencing:
If an empty clutch is balanced on this when new, how does it change? Can a small speed shop afford the proper equipment to do this with more accuracy than the manufacturer?
If it is an out of balance problem from shimming, then it is the techs fault...ps why are you shimming for belt clearance? I know it is what people do, but did you ever think about what removing shims does to belt side force and shift force at any given shift point....it reduces both...the weights are tucked...there are better ways to set neuteral side clearance that don't reduce shift/side force....twin motors with good torque don't like this...mountain sleds need belt side force because of the load going in the steep and deep...
If the clutch is out of balance from wear, the main core is probably junk anyway...ie sharp cuts from weights in the spider or grooved sheaves....
Blind faith at the cost of performance and money = too common...when some one questions the norm with fact they will be bashed....even by the super moderator... I brought this up a month ago...then Indy Dan did...now I will be bashed probably instead of...Hmmm ...
I welcome clutch tuning/rebuilding debate....I do have experience in this subject...:fencing:
There are some great questions on here... all of which add to people understanding their machines better if they take the time to.
Lets start with the origiator of the this thread IndyDan... Have you called Dan on the number he listed in his signature and asked him what equipment he is using?...
I actually don't see any Debate.
I've personally have seen dozens of brand new, on the floor machines delivered by the factory with double to 4 times the factory recommended side clearance... yes, I brought the Starrett feeler gauges with me. So, yes, clutches often DO need to be shimmed to make them function as they should.
I helped a (now) friend with his 2009 Dragon that did not pull R's since new... dealer tried everything... He finally got down to the last item that could be done... swapped him out a "loaner" clutch from a new sled, put in his weights and spring and now the sled pulls recommended R's no problem.
Answer: The clutch was NOT balanced well from the factory...go figure.
Shimming for belt clearance is VERY common... even pointed out in the factory manuals. Shimming the clutch allows you to set the Proper side clearance on the belt... without proper side clearance.. you have rideablity issues, clutch wear issues, performance loss, crankshaft stress, belt wear If you change belt type, if it didn't meet spec from the factory... If it is just plain off... the factory can not afford the kind of individual quality control that you can find in a reputable machine shop... plain and simple.
Common enough to put in the service manual...in detail
Most (but not all) techs either cant take the time (business) or don't know how to index... and even if they did, there is a good chance that the balance will not be "dead on" any longer... IF it was in the first place.
"Little effect" is a subjective comment... and shows the lack of precision built into the factory mentality... especially if it has been shimmed often like on the 900's that had 4 different belts that should have been shimmed/indexed for.
Indexing is not always possible... and even when it is, the balance IS changed... just not enough for the factory to warrant a new balance which they do not do... If a warranted clutch is found to be out of balance.. it is replaced as a unit, not re-balanced... they don't even have this built into the service program.
I lost a clutch... that was warranted, because the spider nut was never tightend at the factory and the clutch failed... On the first ride... So again, I believe that a quality shop can do MUCH better than the factory.
I'm sincerely interested in the "better ways"... I always like to learn.
If you are referring to me, I am curious as to where so that I can adjust my personal skills.
I have seen plenty of pizz poor brand new clutches, and even more that are not maintained that cause problems... balancing is one of them... and for such a critical piece of equipment, the Primary clutch... primary in that it is THE link from the engine to the remaining drivetrain.... IMO, you should make it better than the "ballpark" setup that we get from the factory... and that doesn't just apply to the Polaris.
Which was the one of the scenarios in the first post of this thread (clutch #5 & 6).
Sometimes you have to buy a new one... Which, IMO, should be checked, and shimmed for the belt being used. (not done at the factory as it does not come with weights)
I also believe that the thread was meant to point out that not all people can machine the sheaves.. and that he does as he pointed out.
Keep the good discussion going here!!
Lets start with the origiator of the this thread IndyDan... Have you called Dan on the number he listed in his signature and asked him what equipment he is using?...
I actually don't see any Debate.
I've personally have seen dozens of brand new, on the floor machines delivered by the factory with double to 4 times the factory recommended side clearance... yes, I brought the Starrett feeler gauges with me. So, yes, clutches often DO need to be shimmed to make them function as they should.
I helped a (now) friend with his 2009 Dragon that did not pull R's since new... dealer tried everything... He finally got down to the last item that could be done... swapped him out a "loaner" clutch from a new sled, put in his weights and spring and now the sled pulls recommended R's no problem.
Answer: The clutch was NOT balanced well from the factory...go figure.
Shimming for belt clearance is VERY common... even pointed out in the factory manuals. Shimming the clutch allows you to set the Proper side clearance on the belt... without proper side clearance.. you have rideablity issues, clutch wear issues, performance loss, crankshaft stress, belt wear If you change belt type, if it didn't meet spec from the factory... If it is just plain off... the factory can not afford the kind of individual quality control that you can find in a reputable machine shop... plain and simple.
Common enough to put in the service manual...in detail
Most (but not all) techs either cant take the time (business) or don't know how to index... and even if they did, there is a good chance that the balance will not be "dead on" any longer... IF it was in the first place.
"Little effect" is a subjective comment... and shows the lack of precision built into the factory mentality... especially if it has been shimmed often like on the 900's that had 4 different belts that should have been shimmed/indexed for.
Indexing is not always possible... and even when it is, the balance IS changed... just not enough for the factory to warrant a new balance which they do not do... If a warranted clutch is found to be out of balance.. it is replaced as a unit, not re-balanced... they don't even have this built into the service program.
I lost a clutch... that was warranted, because the spider nut was never tightend at the factory and the clutch failed... On the first ride... So again, I believe that a quality shop can do MUCH better than the factory.
I'm sincerely interested in the "better ways"... I always like to learn.
If you are referring to me, I am curious as to where so that I can adjust my personal skills.
I have seen plenty of pizz poor brand new clutches, and even more that are not maintained that cause problems... balancing is one of them... and for such a critical piece of equipment, the Primary clutch... primary in that it is THE link from the engine to the remaining drivetrain.... IMO, you should make it better than the "ballpark" setup that we get from the factory... and that doesn't just apply to the Polaris.
Which was the one of the scenarios in the first post of this thread (clutch #5 & 6).
Sometimes you have to buy a new one... Which, IMO, should be checked, and shimmed for the belt being used. (not done at the factory as it does not come with weights)
I also believe that the thread was meant to point out that not all people can machine the sheaves.. and that he does as he pointed out.
Keep the good discussion going here!!
This excellent post by " RON " on the forums about the primary clutches is very popular.... Over 19,000 views.
http://www.snowestonline.com/forum/showthread.php?t=87640
It outlines many of the shortfalls of the factory clutch assembly and balance.
Bottom line, If you want the sled to perform optimally...have the primary set up so that it functions perfectly... everything else relys on it. ...
Of course, IMO.
http://www.snowestonline.com/forum/showthread.php?t=87640
It outlines many of the shortfalls of the factory clutch assembly and balance.
Bottom line, If you want the sled to perform optimally...have the primary set up so that it functions perfectly... everything else relys on it. ...
Of course, IMO.
B
Mountainhorse, I appreciate your politeness and open view in this discussion. My main point is to inform the average sledder on here that once a clutch is balanced (and on this you and I will disagree as to the factory quality of balance-and that's ok), that unless you re-shim so your sheaves aren't indexed to each other anymore-there's no reason to rebalance the clutch every year as some like to do. It is simply a waste of money-because, as I stated in my first post, rotating pieces of solid aluminum and steel cannot become "unbalanced". And a good shop can get your sheaves indexed no matter what clearance you require. Speaking to a clutch manufacturer that shall remain nameless but we all know, the spider has little effect on balance, because of it's light weight and more central location-i.e. the closer something with little imbalance is to the center of a spinning object, the less effect it has on vibration. So a shop that does not use the spider as an index tool to get the sheaves lined up is doing it improperly to begin with. My other main point was to help people understand that factories-trust them or not-are using much more technologically advanced machines than we are exposed to-and to trust a bubble balancer or a rotating balancer that I'm sure most people are using above a computerized dual axis electronic balancer made specifically for balancing clutches is not the most intelligent sounding idea to me.
Also, as pointed out, to set belt to sheave clearance at 0 or near zero clearance not only takes away belt side force-which is huge in the trees and at the start of a climb off idle, it causes accellerated wear on the sheaves-through the belt constantly rubbing on the sheaves as well as the slippage associated with less side force. And we all know how hard the new belts are on sheaves to begin with. Also, factory belts vary much more than .010 in width, so to set your sheaves that closely together to begin with-and unless you know for certain you have the widest belt the factory ever manufactured to set your clearance to-is definately not the best of practices. Think of your weights as a teeter totter with a heavy kid on the long side of the board (the main part of the weight) and a little kid on the short side of the board(the teeny little heel behind the pin). To tip the heavy kid lower towards the ground makes it even more difficult for the skinny kid to get him up in the air. Setting belt clearance this closely is like putting the big kid closer to the ground. It takes away the pinching force the weights have right off the get go. And, yes, there are ways to set belt side clearance and still maintain proper weight tip in-even improve it-but I'm not here to sell anything.....Cheers and let's keep it going....
Also, as pointed out, to set belt to sheave clearance at 0 or near zero clearance not only takes away belt side force-which is huge in the trees and at the start of a climb off idle, it causes accellerated wear on the sheaves-through the belt constantly rubbing on the sheaves as well as the slippage associated with less side force. And we all know how hard the new belts are on sheaves to begin with. Also, factory belts vary much more than .010 in width, so to set your sheaves that closely together to begin with-and unless you know for certain you have the widest belt the factory ever manufactured to set your clearance to-is definately not the best of practices. Think of your weights as a teeter totter with a heavy kid on the long side of the board (the main part of the weight) and a little kid on the short side of the board(the teeny little heel behind the pin). To tip the heavy kid lower towards the ground makes it even more difficult for the skinny kid to get him up in the air. Setting belt clearance this closely is like putting the big kid closer to the ground. It takes away the pinching force the weights have right off the get go. And, yes, there are ways to set belt side clearance and still maintain proper weight tip in-even improve it-but I'm not here to sell anything.....Cheers and let's keep it going....
I'll throw in a dumb question.....since we don't operate without a belt, how does the belt affect this? I'm struggling to come up with a good analogy, but could it be compared to trying to balance your truck tire/wheel assembly with a tire that is constantly rotating and changing position on the wheel?? I'm all for a balanced clutch but we also have the primary spring resonating and the belt tugging and pulling and also becoming a MAJOR force in the rotating mass.....so it seems that no matter what it will never be perfectly balanced (or even close) when in operation.....except for those riding without a belt.
If it was possible to measure the "balance" while in operation on the sled, what would we see??
Or am I completely off my rocker....again :face-icon-small-win
If it was possible to measure the "balance" while in operation on the sled, what would we see??
Or am I completely off my rocker....again :face-icon-small-win
B
Your thought process is sound. The reason that you can't include the belt into the balancing equation of the clutches is that the belt isn't static to the clutches, i.e. a different part of the belt touches different sections of the clutch on each rotation of the belt-so taking that into consideration isn't possible, whereas a tire on a wheel is constantly beaded to that same part of a wheel on a car. Of course, you shouldn't run a belt missing sections or with burned spots in it....
One of my points... On my last 2 two-month road trips I DID take the time to check brand new, ready to deliver, sleds... all but one had anywhere near the 0.020" factory specified side clearance ....most were well above 0.060 (which gets worse as the belt wears). A few were less than 0.010" and 2 were at zero or worse. The average Joe does not know this and just rides and has premature belt wear or crank pin problems.
On these NEW sleds... all but one NEEDED to be re-shimmed.
.
On this, my friend, we agree. Once it IS correct for shim and ballace, and IF it is maintained and belts are changed when worn out or the clutch is replaced when IT is worn out....then the balance should not need to be re-done. A worn out clutch cannot be balanced or rebuilt and should be scrapped.
Many shop that shim clutches don't put the extra time to index the clutch IF they even did take the time to shim the clutch to the PROPER factory specs (as specified to sled mfg by the clutch mfg)
Very true... Just don't let the primary get out of index or loose or worn.
A GOOD shop yes... or someone with the right specialty tools and the patience to do it.
In Mankato? :face-icon-small-win
The mfg of these clutches uses a robotic balancer with Liberal tolerance specs for balance. Yes they are MUCH better than someone with basic balance equipment and a basic knowledge of use... but in the hands of the right machinist with the "right" machine... I am confident that a much better balanced clutch with smoother operation than stock is probable. Production requirements and QA checks are done only in random samples at the factory....Churn and burn.
I have taken a factory installed P-85 from a 2007 Dragon that was properly shimmed from the factory (if you can belive it:face-icon-small-con)... this sled vibrated like a buzz-bomb... had it balanced, nothing else, and the sled was transformed into a smooth running machine. If there is vibration in a sled, the balance should be checked/adjusted if you want it to perform properly and "feel right".
Though by their own admission has an effect that they cannot build for in order to be field serviceable. In my discussions with them, there can be a problem if the spider is out balance, then the clutch (as an assembly) is balanced to accommodate that out of tolerance spider (or button) and is then moved in the field to index for PROPER side clearance.
I'd add that is true for MOST of the shops we are exposed to, but not all.
Yes, I agree, zero side clearance is BAD.... 0.020" is Proper for a broken-in (not worn) belt.... MORE is BAD too as this will open up from normal belt wear... which is getting to be less of an issue with the newer PBO belts.
This has changed in recent years. The new cut and ground belts (chart below) are much more accurately made than just 5 years ago... unfortunately the price has gone up as well...
The PBO belts are cut THEN CNC ground for very tight belt-to-belt variance. In a box of 50 115 belts that I checked (I acutally only checked about 30 random ones in the box to be truthful) most on with a Starrett digi caliper... the variance was within .003" for width. So at least with the PBO belts.. you CAN set them more accurately and enjoy smoother clutch operation.
That is why the factory that makes the clutches and most reputable clutch tuners do not set the clearance at zero... In this case 0.020"... More than that and you hammer the belt which will "scallop" the surface and cause premature belt and sheave wear.
The sheaves do not need to "slam" into the belt to prevent slippage... Again, the correct amount of clearance should be maintained.
Like the Adjustable covers which I like... the downside is that they also change the pre load force and finishing force of the primary spring... for small changes this should not be that large of an issue.
If I read it correctly... you point is that many people are being "sold" on something that might not be necessary OR worse yet.... they are not getting ANY value for the money spent...
Some services do NOT give value.. others DO.. which is the point of the primary post in this thread:face-icon-small-sho
I agree with this AND I believe that the production of Primary clutches from AC and Polaris leaves much to be desired as sold to the end user. In my direct experience, I have made night and day differences to the performance of the sled, using the same springs and weights, by having the clutch setup done to match the factory specs AND be balanced very well.
Paul,
In answer to your question... the new belts from the big 4 on their top performers (like your XP, an M8, or the D-8's) are much more accurately mfg'd and are very consistent belt to belt... as pointed out above.. by nature the belt needs to be inherently balanced in the mfg procedure if it is to perform well... I believe the new generation of drive belts meets this goal.
As a sidebar... IMO.... take the time to break in your new belt AND the spare before you do any demanding riding (not when you are rushing to go "get some"...you will be happier in the end.
