"Road-force balancing"

[Paul Workman]

I had an "Ah HA!" moment a couple weeks ago.

For some time - ever since I bought the last set of tires (Nitto 555/555Rs) I had a slight, just perceptible vibration that would happen between 80 and 90 or so mph that seemed to be at the front. This was in spite of several trips to the tire shop to verify balancing.

I'm familiar with the process (I used to "do tires" in a previous life), and they allowed me to look over their shoulders as they checked the balance. But, still the vibration persisted. (Alignment and bushings were checked too in the inteim.) The only thing out of spec was we found a 1/8" wobble on the LR A-mold wheel.

Discount Tire offers road force balancing at no charge, perhaps since I was buying new tires? It did take longer to do so, but all 4 were right-on when finished. And NO vibration!!:-D

The take-off (old) tires were not checked for road force compliance, as were the new tires. So, I can only assume the persistent vibration went undetected in spite of balancing which may have been caught had the tire(s) been road force balanced in the beginning? I'm going to guess on the affirmative. AND,from now on...

[scottskill]

What is the process of road force balancing?

[mike100]

I took off some old tires on my truck and it was amazing that the vehicle no longer pulled to the right after the new set was installed. Also the last set of tires on my c6 was unbalanceable- it was cheaper to buy a pair of new continentals than it was to keep spending on balancing (I think they were slipping on the rim).

I think the more premium priced tires are not all because of a good rubber compound, but a higher degree of quality control or a lower yield - or another words- they will scrap a tire rather than sell it if it isn't perfect.

[WARP TEN]

Paul, I had the same problem on Warp Ten. It had Sumis on it and when I first went down to BG in 2013 with it I noticed some minor imbalance. Jim Van Dorn was kind enough to try balancing the tires but he lacked some needed weights. So I ended up at a local shop --S&R Tires on Lover's Lane in BG -- which had a Road Force balancer. They were great and professional. A couple of tires needed to be rotated on the rims to get them smooth but one tire could not be properly balanced at all as it was so far out of spec. Much improved after their work but I still had to live with a little imbalance. Maybe this is why. in part, Sumis are so cheap. Anyway, once I installed Michelins (Costco) I did not have any balance issues. And Costco did not have a Road Force balancer. --Bob

[Racinfan83]

Most of YaAll know all the fun I've had trying to diagnose a vibration in mine for the last 3 years. RF balances, regular balances, new tires, different wheels, shimming wheels to make them hub centric, yada yada yada..
I haven't had the car out much since I R&R'ed the trans/clutch/pilot bushing and I need to drive it for 50 miles or so to confirm - but I still had my winter tires on it (Which failed the Road Force Balance) when I made my maiden test run after I got it back together. Vibration was significantly reduced if not mostly gone. Took those tires/wheels off and put on my newer set with the 5 spoke wheels and took it out for another 10 mile romp - same deal. Almost no vibration. It's been sitting since due to no friggin time to get it out - so I need to run it some more to confirm - but right now it appears that something I did when I took the driveline/C Beam out (Used Bill's C-Beam Plates when I reinstalled) may have fixed it. I cleaned/polished all the mounting points and flanges, and used the recommended Window Weld on the C Beam, and it sat a couple days setting up before I drove it. So who knows what happened but fingers crossed the vibration is mostly gone...

[8cam]

Regular balancing is typically done at a very low rpm, probably about 20mph equivalent. I've never heard of it called "road force balancing" and my local Discount Tire just balances tires the normal way. However high end tire/wheel shops will do on-car, high-speed balancing. Butler Tire here in the Atlanta area offers it. They have a machine that spins the wheels mounted to the car at 80mph, and then do a fine balance. That works amazingly well, and will remove all vibration issues that are due to the wheels. I do that with my performance cars and love the results.

[Mystic ZR-1]

Read all about road force balancing
at www.Hunter.com
They even have a listing of who
has their equipment so you can find
someone local

[Hog]

Regular balancing is typically done at a very low rpm, probably about 20mph equivalent. I've never heard of it called "road force balancing" and my local Discount Tire just balances tires the normal way. However high end tire/wheel shops will do on-car, high-speed balancing. Butler Tire here in the Atlanta area offers it. They have a machine that spins the wheels mounted to the car at 80mph, and then do a fine balance. That works amazingly well, and will remove all vibration issues that are due to the wheels. I do that with my performance cars and love the results.

I have a machine that will spin up the wheel/tire to speed whilst the assembly is mounted on the car. Dad always said that his way of balancing was better than the off car machines because ALL of the rotating parts are balanced, not just the wheel/tire.




Here is a Motortrend video that explains "road Force" balancing.
http://www.motorweek.org/features/goss_garage/road_force_balancing/

[WARP TEN]

Read all about road force balancing
at www.Hunter.com (http://www.Hunter.com)
They even have a listing of who
has their equipment so you can find
someone local

That's how I found S&R in Bowling Green --Bbo

[efnfast]

We used to have a guy that would shave the tires on the car to balance them. Like said earlier, this would balance all the rotating parts. i heard this worked wonders, but the company no longer exists.

[Roadster]

We used to have a guy that would shave the tires on the car to balance them. Like said earlier, this would balance all the rotating parts. i heard this worked wonders, but the company no longer exists.

If I remember correctly that was called "tire truing" or getting your tires "trued". Same principal as getting your rotors or drums cut. Did this with my first car, a 66 Impala. Had constant problems with vibration, that's when the alignment shop "trued" my tires, vibration eliminated. It did cost a few $$ though. The machine was kind of neat that did the job, as you watched some of your tire tread drop to the floor when shaved.....

[Hib Halverson]

Keep in mind that "road force" balancing is a band-aid for other problems. Yes, it's a capable band-aid, but still...a band-aid.

If you are putting high-quality tires–meaning minimally out of balance, nor out-of-round–on nor with any mass distribution problems–on wheels which are not out-of-round nor have runout and if the tires have been properly mounted, you don't need "road force" balancing.

Bottom line: it all starts with good tires and wheels.

If you're putting POS Summitomos on wheels which are out-of-balance, out-of-round or have run-out and they're mounted by some grease monkey using a tire machine which was new in 1960, well, yeah...you may need "road-force" balancing.

In 20 years of owning a ZR-1, I never had a significant balance problem because I used nothing but Goodyear tires–either GS-Cs, F1GS-D3s or F1 Supercars–ran them on one of two sets of stock A-Molds and had the tires mounted/balanced by the same tire serivice which used premium mounting equipment.

[Paul Workman]

Keep in mind that "road force" balancing is a band-aid for other problems. Yes, it's a capable band-aid, but still...a band-aid.

If you are putting high-quality tires–meaning minimally out of balance, nor out-of-round–on nor with any mass distribution problems–on wheels which are not out-of-round nor have runout and if the tires have been properly mounted, you don't need "road force" balancing.

Bottom line: it all starts with good tires and wheels.

If you're putting POS Summitomos on wheels which are out-of-balance, out-of-round or have run-out and they're mounted by some grease monkey using a tire machine which was new in 1960, well, yeah...you may need "road-force" balancing.

In 20 years of owning a ZR-1, I never had a significant balance problem because I used nothing but Goodyear tires–either GS-Cs, F1GS-D3s or F1 Supercars–ran them on one of two sets of stock A-Molds and had the tires mounted/balanced by the same tire serivice which used premium mounting equipment.

Was this ^^ a "shot across the bow", Hib?

You'll get no argument against everything being 'perfect' - road force tests and basic balancing too would be moot, in a perfect world. But, they use wheel weights, even on "quality" manufactured tires, yes?

No "significant" balance problem... Hmmm.... Well, that's very subjective. And, it depends on the application/driving style and the speeds driven.

The only point I was trying to make was, road-force balancing is another test in addition to "traditional" spin balancing that can further evaluate tires/wheels and could shine a light on a flawed tire that may otherwise have gone undetected.

[WARP TEN]

You are right, Hib--nothing is better than starting with a good set of tires and hopefully reasonably true and well balanced rims. But without the guys doing the Road Force balance on the Sumis I had, I would not have known that two tires needed to be spun on the rims, as they were out of position to facilitate easy balancing. No one else noticed that. And I would not have known that one of the tires was so far out of whack that it could never be properly balanced. As you also note, professional experienced experts with top of the line equipment can resolve a lot of issues. Just simpler to start with good tires. I switched to Michelin Pilot Sports which were great--no balance problems. --Bob

[Racinfan83]

Update on my earlier post: I finally took the car for a longer romp on some smoother roads. I was mistaken before. Vibration is still there. One of these days I will be somewhere with one of you guys where I can swap a set of known non-vibrating wheels and tires on it and see what happens. Until then I guess I will live with it...:cry:

[Hib Halverson]

Or maybe...the vibration problem is not tires at all.

[Racinfan83]

Therein why I need a set of known good ones to eliminate the tires and wheels. Because as of right now I have little other way to determine that..:(

[Paul Workman]

Therein why I need a set of known good ones to eliminate the tires and wheels. Because as of right now I have little other way to determine that..:(

Well, like Hib said, the vibration may not be wheel/tire related. Good point.

However, substituting another set of wheels/tires could very well introduce a new/different set of problems. And, more than that, the very point and purpose of RFB is to evaluate the tires AND the wheels together as a unit, beyond simply using weights to compensate for balance. If the RFB isn't in spec before the wheel is verified, it danged well should be before doing anything else.

Bushings, alignment, etc. need to be considered next, especially if the wheels/tires check out.

Out in the countryside and nobody to share the road with, I nudged her well into triple digits and checked for vibration. There was none. She's a sweetheart!

[WVZR-1]

Update on my earlier post: I finally took the car for a longer romp on some smoother roads. I was mistaken before. Vibration is still there. One of these days I will be somewhere with one of you guys where I can swap a set of known non-vibrating wheels and tires on it and see what happens. Until then I guess I will live with it...:cry:

Two years ago I suggested this:

http://www.zr1.net/forum/showpost.php?p=205058&postcount=17

You need a car that satisfies your desired "driveability" before even considering the wheel/tire swap. If the car doesn't satisfy you the swap is a wasted effort. You need to duplicate the MPH/RPM where you "feel" yours to the same MPH/RPM in the "other car".

Since you've chased this at great length maybe you should consider contacting one of the GM dealers you developed a relationship with and use a Kent-Moore EVA2 to try and locate your source of vibration. Is there newer than the EVA2? Maybe!

A short discussion a few years old regarding the EVA2:

http://www.searchautoparts.com/motorage/technicians/undercar-service-repair/bad-automotive-vibes

[Racinfan83]

Yes I know. I don't drive the car much and haven't had time or funds to work on chasing it down. I have to get it inspected here soon for new plates so will see if they can do something with it then. Or one of these days I need to drive 5 hrs and get with the FBI crew... I was hoping it went away when I did the pilot bushing but I guess that was wishful thinking...

Sent from my LG-H830 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[Johnny5]

I had an "Ah HA!" moment a couple weeks ago.

For some time - ever since I bought the last set of tires (Nitto 555/555Rs) I had a slight, just perceptible vibration that would happen between 80 and 90 or so mph that seemed to be at the front. This was in spite of several trips to the tire shop to verify balancing.

I'm familiar with the process (I used to "do tires" in a previous life), and they allowed me to look over their shoulders as they checked the balance. But, still the vibration persisted. (Alignment and bushings were checked too in the inteim.) The only thing out of spec was we found a 1/8" wobble on the LR A-mold wheel.

Discount Tire offers road force balancing at no charge, perhaps since I was buying new tires? It did take longer to do so, but all 4 were right-on when finished. And NO vibration!!:-D

The take-off (old) tires were not checked for road force compliance, as were the new tires. So, I can only assume the persistent vibration went undetected in spite of balancing which may have been caught had the tire(s) been road force balanced in the beginning? I'm going to guess on the affirmative. AND,from now on...

i bought my tires from discount tire direct but did not know they offfer the road force balancing as i paid extra at a shop to have it done. where do they do that? do u have to go to specific shops?

[Paul Workman]

i bought my tires from discount tire direct but did not know they offfer the road force balancing as i paid extra at a shop to have it done. where do they do that? do u have to go to specific shops?

That sounds like a question for your local dealer. The two shops I use (Joliet and Bourbonnais, IL) offer it.