Do you balance the wheels on your racing car?

[Kroggers]

Originally Posted by Jittsl

I don't know where the quote below the picture came from but it seems to imply they no longer balance tires.

And before I get jumped on for complete ignorance- I have no idea whether Indy cars have balanced tires or not. Would seem logical that they would on the basis that any advantage at that level would not be ignored. If however they are anything like F1 tires they probably do not maintain balance for long - how many times have we heard drivers complaining over the radio of "shake".

As soon as Alonso moves over and I get his seat I'll probably ask for my tires to be balanced until then I'm fine with out of balance tires. I don't think there is any time to be had in a little less shake in the first couple of laps.

Can we assume from this that you do not balance your racing wheels?

[Sumflow]

Originally Posted by Kroggers

Can we assume from this that you do not balance ...

I think the main question should be is static balance alright, or do we need dynamic balance?

[Jittsl]

I think the main question should be is static balance alright, or do we need dynamic balance?[/QUOTE]

Hmm. I must confess I have never seen the distinction made above. Sumflow, did you make that up just to fool us dumb folk?

The "dynamic imbalance" you show in the image looks a lot like what I would call a bent wheel. If true then I probably don't accept dynamic imbalance. If the wheel doesn't run true I throw it out.

If it appears to run true but gives a little wobble in the steering wheel or shake in the car (apparently the output of static imbalance by the previous diagram) then I just live with it - I got plenty of other stuff to really worry about.

Laurie

[stephen wilson]

I think the concept is this: If the tire has a "heavy" spot towards the outside edge, and you put the balance weight on the inside edge of the rim, it will balance in a static test, but not dynamically. The offset between the two masses causes a "wobble" , that axis is what the drawing is trying to represent.

[BYprodriver]

Originally Posted by Sumflow

I think the main question should be is static balance alright, or do we need dynamic balance?

Static imbalance is a up & down force

Dynamic imbalance is a side to side force

[Jittsl]

Originally Posted by BYprodriver

Dynamic imbalance is a side to side force

What (other than a bent wheel) would cause a side to side force? Seems to me that all forces on a unbent wheel (ie forces derived from rotation around a single fixed axis) would be "up and down".

[stephen wilson]

Originally Posted by Jittsl

What (other than a bent wheel) would cause a side to side force?

Read post #24.

[Jittsl]

Originally Posted by stephen wilson

Read post #24.

I did steve but here is my problem: if I have a heavy spot on the outside edge of a wheel the compensating weight would be placed on the same edge 180degrees away. Wouldn't it? I am no expert so I'm looking to understand here.

[stephen wilson]

Originally Posted by Jittsl

I did steve but here is my problem: if I have a heavy spot on the outside edge of a wheel the compensating weight would be placed on the same edge 180degrees away. Wouldn't it? I am no expert so I'm looking to understand here.

The key is, if you're not dynamically balancing, you won't know if the imbalance is towards the inside or outside, so getting the weight in the exact right spot is a crap shoot.

[BYprodriver]

Originally Posted by Jittsl

What (other than a bent wheel) would cause a side to side force? Seems to me that all forces on a unbent wheel (ie forces derived from rotation around a single fixed axis) would be "up and down".

lateral runout in the wheel &/or tire or brake rotors

uneven tread wear

damage

heavy spots

nothing is perfect

[Jittsl]

Originally Posted by Kroggers

Can we assume from this that you do not balance your racing wheels?

You would be correct- I think I said that earlier on.

[Brad Roberts]

Balance them. Clean the wheels thoroughly prior to having them balanced. Remove ALL traces of tape/glue/rubber.

The first job given to team newbies for EVERY RACING team in the world.. is wheel cleaner. They are cleaned prior to every single dismount/mount.

Customers paying me to attend track events? I clean the wheels between every round and make sure the weights are taped on after they return from mount/balance.

It takes 5min per wheel. I set them partially into a trash barrel and scrape off the clag

Walk up to any of my cars on grid, and look into the wheels.. spotless..

Jitts:

your way way behind on the GT3 wheels... you have to scuff the area on the rims that the bead sits on. Then.. you have to instruct your mount balance guy to not utilize so much damn LUBE during install. Real race shops/track install guy's use a different lube that evaporates quickly and they know not to use a ton of the sh_t on Hoosiers/Kuhmo's/Toyo's/Slicks.

too many times I have seen people have wheels powder coated, then watch the tires slip big time on the rim throwing the balance off. They have to be scuffed.. all of them.. when generating the braking force of a GT3

I mark all of my wheels at the valve stem with an arrow.. for this exact purpose.. to see if my tire guy is using too much lube

[Brad Roberts]

BY the way.. this is personal preference. I have not met a diver yet that "likes" to have a unbalanced set of wheels running around the track.

The real issue is: if the wheels are unbalanced, how am I going to be able to tell if there is another issue with the car? Wheel bearings going bad can cause a imbalance, axles coming loose can cause a vibration, rear main bearing in the engine going bad can cause a vibration.. lots and lots of reason to balance the wheels to eliminate them from masking another problem.



B

[Jittsl]

Originally Posted by Brad Roberts

Jitts:

your way way behind on the GT3 wheels... you have to scuff the area on the rims that the bead sits on. Then.. you have to instruct your mount balance guy to not utilize so much damn LUBE during install. Real race shops/track install guy's use a different lube that evaporates quickly and they know not to use a ton of the sh_t on Hoosiers/Kuhmo's/Toyo's/Slicks.

too many times I have seen people have wheels powder coated, then watch the tires slip big time on the rim throwing the balance off. They have to be scuffed.. all of them.. when generating the braking force of a GT3

I mark all of my wheels at the valve stem with an arrow.. for this exact purpose.. to see if my tire guy is using too much lube

Thanks Brad, as it is I no longer track the GT3 so not an issue anymore. When I did track it we tried all sorts of tricks and eventually I just gave up and stopped worrying about wheel balance. As I said at the start I have a very inexpensive guy so I do balance the Boxster's tires. Having said that, am I the only guy out there that finds that after a session or 2 between flat spots and built up junk etc. they are way out of balance anyway? Do other people balance tires between replacements?