Spin Balancing vs Staic Balancing

SMSW

Joined
Sep 4, 2013
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Location
Cleveland
Bike
2010 ST1300
For years and years, spin balancing car tires has been touted as the best way to go - maybe because they are relatively wide? An awful lot of posts here say that static balancing is fine for motorcycle tires. I've had cupping on my Bridgestone 023F's front tire and read here that cupping is due to imbalance and tire pressure. (I use a bourdon tube style gauge religiously (gonna check its accuracy soon) and keep the tires at 42). Car tire guys say cupping is due to suspension problems and/or a lack of stiffness in the outside edge of the tire (? - one guy told me this. what do I know?). I have a nearby performance mc shop that will mount and spin balancemy ST's wheels for less than my dealer charges for mounting and static balancing so I will give them a whirl (and maybe my future business, too).

What do you guys think about the relative merits of spin vs. static balancing?

Regarding the dot on the tire going near the heavy area of the rim: Do tire manufacturer's spin the new tire and mark the light area of the tire with said dot? Is the unmounted tire's imbalance due to the overlap of the plies during carcass lay up on the mandrel during manufacture?
 
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I heard many years ago, that equipment manufacturers started the spin balancing deal to sell the 'new' balancing tools, more profit. This would have been in the 1950's and 60's. Yes, I'm that old.
Cupping of the front tire seems to happen to me more often if I have tires with long tread blocks. I'm very careful of the tire pressure, in both bikes, the ST just feels better with enough air, and the Hayabusa doesn't feel right at all if the pressure is low. The cupping happened worst though with Michelin PR's. Dunlop RoadSmart's cup a lot, too. They have very long, longitudinal tread blocks.
Right now I'm trying a set of Shinko 009, Raven tires, the tread blocks are much shorter. I don't care for the rear on my Hayabusa though, the profile is flat and I can feel it when I get close to the edge, it feels squirmy or not as planted. Bridgestone T30's might be my next choice.
 
SMSW said:
I've had cupping on my Bridgestone 023F's front tire and read here that cupping is due to imbalance and tire pressure. (I use a bourdon tube style gauge religiously (gonna check its accuracy soon) and keep the tires at 42). Car tire guys say cupping is due to suspension problems and/or a lack of stiffness in the outside edge of the tire
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Car tires do not take the same "abuse" as motorcycle tires.

It's worth stating it again (seems I've mentioned this 5-6 times in as many days) ... scalloping (some folks call it "cupping") is a normal wear pattern on motorcycle tires. It's more prominent on some tires.

Given that all components (suspension etc) are within spec, no amount of balancing (or adjusted air pressure) will alleviate scalloping.
 
In my experience, I have found that running a tire under-inflated is the biggest contributor to cupping.....& it doesn't take long for the damage to occur. The heavier the load the tire is carrying will also multiply the effect on the under-inflated tire. I have a friend that took a long weekend ride with the wife on back (and, no she wasn't the problem);) & he absolutely ruined a practically new PR2 rear because the tire was under-inflated. I do agree that almost all tires will cup to some degree as they near the end of their tread life.

As for balance methods, I have been to many SB races & they use the same type static balance stands that I use.

John
 
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Either one will work well for any kind of wheel, but both have hitches.

Dynamic (spin) balancing machines are more complex than static balancers and must be properly set up and maintained. When they work, they do a fine job, and other than mounting the wheel on the axle correctly, the parts the operator has to do are pretty much foolproof. Get one out of calibration and you're going to come out with unbalanced wheels no matter how much the blinky digital display insists that everything's good.

Static balancers are simple: one rod, two cones and two bearings. They work just as well and don't have any calibration problems other than making sure the rod isn't bent and the bearings still turn freely. The tradeoff is that the onus of making sure it's done right is on the operator.

The shop that's done my mounting and balancing for most of the time I've owned my ST uses a dynamic balancer. They've and always done fine until this last set of tires, which have an imbalance in the front wheel and weights in places that don't match up with anything I've seen previously. In what's the next step toward not needing help from any shops to maintain my bike, I bought a Marc Parnes static balancer, will be checking the front this afternoon and will re-balance the wheel if necessary. I think just to be safe, I may do the rear as well after I've had the front out for a test ride. (Sharp-eyed readers will remember that I found this imbalance almost a month ago. A business trip, work and an unexpected out-of-town family emergency have prevented me from getting to it until now.)

--Mark
 
I gave up on both methods and have run Counteract beads for the last 2 sets of tires with no problems at all. Never a shake or strange wear pattern. Yea I run Double Dark... I remember back when the spun the tires on the car to spin balance them. That was the most accurate way I have ever seen to do the job. Randy would hold a fist on top of the fender with 1 finger out and when he got it his finger never moved.
 

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Blrfl said:
I bought a Marc Parnes static balancer, will be checking the front this afternoon and will re-balance the wheel if necessary
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I have been considering buying one of these. I would be curious to know how you make out with and if it fixes the problem.
 
Dynamic balancing of a tire ALSO compensates for the weight difference of the tire from side to side. If you go to an 8-10 inch wide tire and wheel combination on your motorcycle then you will probably need to spin balance. Most shops use a balancing machine because it's faster and easier for the technician. If I take my time and I'm really picky about balancing I can very easily have 10 plus minutes in one static balance. A shop could not afford to spend that much time when there are faster alternatives. If I mounted 15 or 20 sets of tires a day I'd buy a spin balance machine. I only balance 5 to 10 tires a year so I do it the old fashioned way, By Hand.
 
Andrew Shadow said:
And the most dangerous for the operator which is why we don't seem them around much anymore.
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Yup but back then that didn't mater. Now days it would have to be done with protective Kevlar wall between you and the spinning tire. I still think about as a kid he told Dad to runner her up to a 100 to see if it was ok. Both wheels off the ground with a jack under the center pumpkin is all that held it up.
 
I quit tire balancing years ago and honestly haven't noticed any difference. I knock all the weights off and statically balance the wheel with no tire mounted once; if tire has a dot I use it, mount and tide.
 
There's a lot of confusion in balancing terminology and their purposes. Balancing can be done statically (not spinning) or dynamically (spinning), but that is not enough to describe the outcomes. There is either single plane balancing or dual plane balancing.

Single plane balance. Can be done statically or dynamically (spinning). If static, it is a single plane balance as you are only determining the weight requirements on a single plane through the CG of the tire/rim assembly. Spinning the tire does not produce a dual plane balance without proper equipment and procedures. Spin balancing (aka dynamic balancing) motorcycle tires has the same outcome as static balancing: a single plane balance.

Dual plane balance. Dual plane balancing is done dynamically and weights are added on either/both sides of the rim, the placement of weights purposely not on the same plane as the CG of the tire/trim assembly. Dual plane balancing requires spinning with multi-axis sensors in the balancer.

Auto tires are wide enough that they benefit from being dual plane balanced. Motorcycle tires are narrow enough and function differently such that motorcycle tires are only single plane balanced.

Balancing.jpg

;-)
 
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