TAI2

I just bought a set of 18" OEM Turbo Twists from another Rennlist member that were in very good condition that I had painted POR1000 and mounted a set of Sumi III's on them. They were balanced on a "regular" Hunter machine but I ended up with a slight shimmy between 55-60mph. Wasn't bad, just annoying considering I was replacing bent wheels. Brought them back, checked the run-out on the wheels, rebalanced........... to no avail.

I then brought them to another shop in the area that had a Hunter GSP9700 Road Force Balance machine. The tires were "balanced" but were more than 25lbs off in one spot. This can be attributed to slightly out of round wheels and slightly out of round tires,etc...... They rotated the tires on the rim per the machine read-out and now I have zero shimmy!!!! :burnout

I have read a lot about checking tie-rods, control arm bushings, tire pressure, warped rotors and wheel balance which are all very important things to check, but not too much emphasis on the type of balance machine to use. When you think about how the road force balance machine works, it makes perfect sense.

Just thought I'd share and maybe some of you who have given up on getting rid of that last bit of shimmy, will now have a low cost solution. Here is a web site you can use to find a Hunter GSP9700 machine in your area.

http://www.gsp9700.com/

Good luck.

Michael S.

I'm a BIG believer in Road Force balancing... It has solved several problems for me that ordinary tire shops could not fix!

Cactus

A friend also told me this took care of a shimmy on his CTS-V. Guesss it's not just hype and extra money!

Richard C2S

I've been having my tires mounted and road force balanced for the last four years. I believe in it big time, so long as the equipmt is regularly serviced and calibrated and the "tech" knows how to use it.

Brian F.

Road Force is an essential tool at our Jaguar/ Land Rover store. I can remember working at a gas station when I was a kid and a bubble balancer was good enough. Now with more sophisticated suspension and tire technology R Force is a necessity. Cheaper tires will exhibit side wall irregularities a little more often.

Brian

Rinty

I just had my car's front wheels Road Forced, but have a light vibration between about 45 and 65 mph. I'll continue investigations next spring, and my tires may be at limits.

Are 993's subject to "wheel fight"? The first generation BMW 320 i's and the Mercedes 6.3 sedans were subject to it, I believe.

Rinty

AOW162435

The same Hunter GSP machine cured imbalance issues I had with my 4Runner from day one (new purchase). I'm on my third set of tires (157,000 miles) and never have balance issues during the life of a set of tires. I rotate often, but also believe in how that machine works.


Andreas

Barney1

Road Force is the way my new wheels were done...Zero problems..all the way up to 185mph+ ( did I say that ?)

TAI2

Hey Mike,

185, wow! I did get it up to 145 on the ride up to Monticello......really cool track. I finally got the new Twists and Sumi's on the car.

Tom

civerson4

I am also a believer in road force balancing. I had a huge vibration issue on my Cayenne at freeway speeds after the 1st set of tires were gone. Since it was still under warranty, I brought it back to the dealer (with receipts for the original balance and confirmation the tires had been re-balanced--but not by a road force machine). Over the course of about 15,000 miles, the Cayenne was back at the dealer 7 times for the same issue. Finally, Porsche was called in and said the vibration was "normal" (and they put it writing). I had essentially given up trying to fix the issue since my lease is going to be up in about 18 months.

I then randomly ran across a hread on the Cayenne forum here about vibration issues with the Cayenne and Pirelli tires that mentioned road force balancing. Found a local Hunter 9700 machine and bought new tires (since the Pirelli's were about 80% gone anyway). This completely solved the vibration issue. It is amazing the dealer replaced so much on the front end of this Cayenne (shocks, strut bushings, brake rotors (twice), even the drive shaft). And all it needed was road force balance. Since it is now solved, looking back it is really disappointing that the dealer didn't think to have this done (or ask me to do it).

Garth S

Having had a fresh set of PS2's installed recently, the car experienced a chassis vibration at highway speeds which could also be felt in the steering: the source appeared to be the LR tire.
All were initially balanced 'conventionally' on the Hunter road force machine: when I returned with this issue, the tech used the 5 finger fixture to mount the wheel ( which was not used initially). This fixture allows the full road force measures to be recorded, and indicated a slight radial runout beyond spec.
We broke the bead and rotated the tire 180 deg - and rebalanced. Problem solved.

All the rebalancing in the world would never solve a problem of this type - for the tire was in perfect balance when we started. 'Road Force' is the way to go ....

jimbo3

+1 on Road Force. Do it right the first time. Lately, Discount Tire has been giving me a discount because I usually come in a couple times a year between the company car and two other vehicles.