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.
WOW!!!!!! Sorry I posted and never came back to see what all went on here...........I don't log on very often.
I can explain.
1 - Bubble balancing drive clutches ( don't )
1 - static and dynamic are completely different and very close to the same depending on how you do and perform the task at hand.
If a drive clutch is complete assembled and you put it on an bearing taper and let the heavy side go to the bottom and then you remove material from the low side and you repaet this process until you get to the point where no matter where you set the clutch it will not move it is now static balanced and in no way dynamic balanced.
If you take that same static balancer disassemble the drive clutch and put the back stationary shiv on by itself and balance it alone to perfect static balance it ineffect is every close to dynamic balanced because it has a machined center post that is long, But it is machine from pure stock it by itself would not require balancing. Then there is the narrow inner sheeve the is to narrow to require dynamic balancing so static balancing gets the job done.
Then after that piece is balanced you spin the spider on a balalnce it again. then you do the moveable by itself and the face plate.
Now each piece even though seperately static balanced will result in the same as being done on a dual plane dynamic balancer.
The problem with static balancing a complete clutch is the fact that it is wide enough like a tire on a car or big truck tire the wider the item the more important it becomes to dynamic balance.
static will find the weight but you do not know where its at.
a
perfect static balanced wide tire can have a heavy spot outside at 12 o'clock and the same heavy spot at 6 o'clock inside and staticly it will seem perfect and it will shake the wheel out of your hands.
Dynamic dual plane feels the inside and outside and tells you where the weights at.
most dual plane balancers cost about $20K
Bubble or static balancing done on drive clutches is a complete waste of time and dangerous.
The factory uses dual plane mass production robotic balancing and most of the time its pretty good..........Its mass production. you make the call on what you think of mass production.
Dan
