Tire Balancing

[Veefan]

I've been tring to get a set of vee rims/tires balanced, and all my local tire shops and gas stations say they don't carry the adaptors any more for the rims. Once shop said he does them for one customer but he has this own adaptor. I could do them myself on an old shool blancer, but always felt for my street cars, the speed balancers did a better job.

Help.... what are you guys doing?

[brian]

I use the bubble balancer with great success if I am careful. The CHinese units are a bit finicky but ok. I found my adapter on ebay. You can use the adapters sold to install chevy rims on bugs "backwards" on a balancer. Just remember to baseline the adapter first. The chevy to vw adapters are quite common at swap meets and shops.

[fv195]

I have used an old front drum, bolt the wheel to it and the speed balancer will take it, now I have my own bubble balancer. local vw shows you might meet people that know of a shop that has the adapter

[Veefan]

I like the idea of using a front rim on the speed balancer (first making sure it's balanced also before bolting it on the rim). I've tried the bubble balancer... and I'm realllly bad at it.

Thanks!!!!

[Dietmar]

VF:

If you can not find anyone to balance the wheels- tires, here is something you can do to get you by:

jack up the front wheels, back off on the brake adjusting screws a couple of clicks, spin the wheel, and wait for it to stop. Loosen the jamb nuts or the aluminum nut that holds the wheel bearing, and the wheel should start to rotate by itself. It will find the heaviest spot - which will end up down. Tape a temporary weight 180 degrees opposite ( at the top of the rim). You will have to experiment with different weights until you get the feel, but this will balance the wheels for you. Give it a spin and the wheel should stop at a different location each time. If not, more or less weight will get you real close. Mark the wheel-drum location so that the wheel goes back on the drum at the same location each time.
If you think the drum is well balanced by itself, then you can do the same with the rear tires on the front drum.
Hope this helps
Dietmar

[Hal]

The tire store I USED to use had an adapter and mounted and balanced my tires for years. Often the tires would leak around the bead and a good spin balance on a tire was a very rare thing, in fact they were usually just awful. Once the bead was not even fully "popped" and they still spin balanced it. It had a big whoop in it when I put it on the car and spun it by hand, how they could not notice that on a spin balancer is beyound me. I bought a tire mounter and bubble balancer from Harbor Freight and saved enough doing 6 of my own tires to pay for the whole works. I had an old front drum lathed down so all there was was the front part, kinda heavy but works great. Bubble balancing is kind of a black art at best and can be time consuming but once you get on to it you'll find it will work quite well. The best balance jobs I have had in the last year or so I have done myself, very easy to see (feel) the difference on the track, especially about a 150 mph....or so.


Hal
FV 88

[Larry Bradley]

Up to 150 is good enough unless you are at Road America or a track with a really long straight.

I heard on TV they said the back straight at RA was a 180 mph straight, so you might want a better balance there

[Hal]

Well ya see, that 150 was at RA and it was a Dietmar motor in my D-13. By the way, it was stuck in 3rd.


Hal
FV 88

[clubford00]

And didnt you tell me you had a new set of carbotech brakes on at the time and they had swollen so much that the back wheels were locked up?

[Hal]

Yes, that and the 140 pound deer that had attached itself to the nose of the car...

[clubford00]

Yeah the one dragging its feet

[jpetillo]

Veefan,

I have a "motorcycle" wheel balancer, similar to this one...
http://www.nomartirechanger.com/product/show/9
I mount the tire/wheel onto a dedicated rear drum (it had stripped splines) and the drum is mounted on the balancer rod with two cones (like the ones shown). You can get it balanced to within 1/3 of a tire weight, easily.

I use a dedicated set of numbered lug nuts and first balanced the drum/lugs alone. The lug nuts didn't make a difference to the balance. The drum was off by two lead squares at a radius of about 4 3/4", which is worth about 1 square at the rim radius (about 7 3/4"). So it does suggest that balancing each wheel/drum combination would be best if you're willing to dedicate each wheel to a drum. I do plan on checking each drum the next time they're off the car, but don't plan on dedicating the wheels to specific rims.

These balancers are very sensitive - very much more accurate than I can get by mounting the wheel on the front of the vee and backing off the brakes. I have one of the JC Whitney/Harbor Freight bubble balancers and mounting plates (you have to use live JC Whitney chat to have them locate the plate). It would be faster - good at the track - but I'm more comfortable with the one above. I don't trust myself with the bubble balancer yet - would need more practice.

John

[Veefan]

Thanks John

I think I'm going to get one of the motorcycle wheel balancers from the link. I took two set of wheels and tires to be mounted at the local tire shop with an old vw hub... they charged me $180.00 I could have got a hand tire mounter and the balancer for the same amount of money!

REWIND to a few posts earlier. .. 180 MPH??? 150MPH??? can a Vee go that fast?

[clubford00]

Sure they do, Wanna Race???
Actually Veefan they do not. 120 to maybe 125 at Road America with a draft is common. You have to realize that we are all "Formula " drivers, which means we are all a little Whacked in the head to begin with.
The above banter is just very tongue in cheek humor, (However i have seen Hal drive with Animals attached to his nose.)

[Larry Bradley]

$180

[jpetillo]

120 to maybe 125 at Road America with a draft is common.

That sounds about right. With an 0.89 fourth gear ratio, 7000 RPM gives you about...

RearEndRatio/Speed
4.375 gives 120 MPH
4.125 gives 128 MPH

There's just a 5.7% difference between rear end ratios.

John

[Dmclellan]

Based on my GPS Data system: 88.35 MPH at 5313 RPM would make my car do 116.4 at 7000 RPM. I don't know how accurate my Traqmate system is.

[FM4SOLO]

My gearing calculator shows a touch over 117 with 4.375 R/P, .89 4th on 22" tires.

[clubford00]

Remember, these are estemates. I have been the 14th car in a 14 car draft at R.A. and 7000 to 74000 rpm is possible. Scary as hell as your waiting for the rods to hit you in the back of the head. I had the timing perfect, pulled out just after the kink and was 1st of the pack going into canada ........only to be 14th again at turn 1 (sigh). so drafting plays a monster roll in racing at R.A.

[jpetillo]

My gearing calculator shows a touch over 117 with 4.375 R/P, .89 4th on 22" tires.

Yes, I agree with your numbers for 22" tires. I forgot to mention that I was using 22.5" as the tire diameter. Yours may be a better number to use. Did you measure it? I should measure the rolling radius to get a better estimate - at least for low speeds. The tire would be slightly larger at higher speeds - but I don't know by how much.

Based on my GPS Data system: 88.35 MPH at 5313 RPM would make my car do 116.4 at 7000 RPM. I don't know how accurate my Traqmate system is.

That's only about a 3% difference from my theoretical numbers. Assuming that you're using a digital tach (looks like it) and your GPS speed is accurate, that would suggest that Charles' 22" tire diameter is a good estimate.

John

[clubford00]

220 , 221 Whatever it takes ..

[FM4SOLO]

I run a Solo Vee, so I made an RPM to Speed calculating spread sheet to decide on the new 3rd and 4th gears (legal to change in Solo) I installed over the winter. I use both 20X9 and 22X10 R25 Hoosiers. The actual diameters are slightly larger, but the spreadsheet was useful in determining RPM drop between gears, max speed, etc.

I haven't balanced any of the tires I've run, but Solo speeds are much lower than Club Racing speeds. The Diamond steel wheels and Hoosier tires have been very stable, I haven't experienced any problems.