Spin balancing hot rod tires

[donsrods]

I've always just had someone like Pep Boys or Tire Kingdom balance the tires on my hot rods and for the most part that has worked well. But I plan on racing my 27 at the Billetproof Drags Oct 23rd and since I will be going faster than I ever drive on the road I wanted to make sure everything was right.

I have been noticing a slight vibration in my steering wheel when going down the road, not bad, but there. So today I found an old truck tire/alignment shop that has been around for 33 years and who is about the only place in the whole area that balances the tires on the car by spinning the whole rotating assembly.

The tires on the front of my car are 5:60 x 15 bias plies from US Royal and I have bolted on the 8 inch x 15 Firestone slicks from my rpu project just for the day I race. I thought I might need the tires shaved to true them, but the technician said they were fine, but they were way out of balance. Surprisingly, my rear slicks were right on the money and needed nothing done.

It only cost me $ 44 plus a tip for the tech, and I was out the door, and what a difference ! No more vibration in the steering wheel and I can watch the front tires rolling down the road with no hop whatsoever.

The tech thought I was nuts taking a picture of the process, but I thought it might help anyone on here who has been having similar issues or thinking about having this done.

Don

 

[Dr Crankenstein]

Holy crap! I haven't seen one of those machines since high-school shop! Proves that old technology is better in a lot of ways. The one we used could also free-wheel so you could run it under a rear tire with the car running. If I recall correctly, we spun the speedo up to 80MPH, as the manual instructed. Stand back, pebbles and crap come off the tire at bullet speed!

Watch a tire shop balance a tire and wheel today. Those machines spin pretty slow. No real dynamics come into the equation, and there's no accounting for the hub it's attached to.

Slicks to my knowledge are supposed to be perfectly matched as a pair, and they should be true when you get them. We used to have them checked when mounted, anyhow. Only ONE shop in town had a high-speed balancer that could check them properly, which makes me wonder how bad some "normal" tires really are.

Anyhow, thanks for posting, Don. I'd forgotten about that method, I'm sure it'll come in handy when the regular balance machines show nothing.

 

[donsrods]

Dr. C, yep, he ran the front tires up to about 120 mph he said, and they ran nice and true when he was done. He had me get in the car and run the car in high gear while he put it under each rear tire. He had to do it that way because the car has positraction, so he couldn't spin the tire with his machine.

All I know is that the car really feels so much better now.

Don

 

[Sam_Fear]

Very cool old tech. Wish I had a good reason to search that out.

 

[sgtpontiac]

Had one of those....at my service station...

Had a sensor that went under the frame and measured the vibration of the whole car.... I can remember using my forehead against the fender to feel the vibration directly....worked really well but sometimes a stone or pebble would become a missle and go bouncing around the shop....ahhhh the good old days... they really balance the entire wheel, drum and or rotor so you could make it silky smooth at highway speeds and above....of course above...nice post.... memories.....like the corner of my mind....sorry...

 

[donsrods]

It really made a difference in the feel of the car going down the road, so glad I did it. Last night I did a tune up on the 27 and uncorked the headers. I am ready for the drags.........only 11 more days !

Don

 

[FordFanatic]

How do they know where and how much weight to attach? Trial and error ?

 

[sneakysnake]

Never seen it done that way,yall guys must be real old.LOL

 

[Sniper]

How do they know where and how much weight to attach? Trial and error ?

Used the same principal on the big truck front tires, had a small hydraulic cylinder on a stand (looked kind of like a bottle jack) with a four foot hose and a gauge attached to the end of that. You jack up the front end and set it back down on the end of the hydraulic cylinder. As the tire spun up, the out of balanced tire would compress and decompress the oil as it rotated, making the gauge move. The gauge was graduated in ounces of weight. You found where to put it with a strobe light aimed at the side of the tire near the bottom. The strobe made it look like it was standing still, that's where the weight would go.

 

[sgtpontiac]

Mine had a clamp on piece...

would clamp to the inside of the rim and had a balancing mech at the middle...as you spun it up, you moved three little wheels that were in the center of the clamped on device....when the vibration stopped, it was balanced..after a while it would take about 5 minutes to balance if it was really bad...you stopped the wheel and it showed the heavy spot.... I always triangulated the weight...if it was 1.5 ounces I'd put 3/4 and 3/4 in an arch so that there were not two heavy spots...it would look like I divided the tire into thirds....I'd have to run it a second time to double check it but after a bit, I just knew where to put the weight and the next spin up was perfect.... did the same thing on the old bubble balancer....triangulate the weight so there were 3 spots instead of two...seemed to make a better balance....even with a simple bubble machine.... used those for years as a kid at the cab company....I think my spin balancer was a Bear brand....the stobe light one I bought later was a snap on..... used them both with great results...