Question on roadforce balancing?

bimmer01 · 06-30-2009, 07:43 AM

I bought new General Exclaims form Tirerack and yesterday I had the fronts put on and roadforce balanced at the dealership. I'm going to do the rears today, I only crammed 2 in the car at a time to cut down on wear and tear

Anyway, I guess i just never realized that when you do a roadforce balance you get an actual # associated with each wheel in pounds of force. Probably no one bothered to actually give me those #'s in times past, so now I'm just curious as to exactly what they mean. Anyways, the driver's side front tire came out with a road force of 12 lbs. and the passenger front came in with a road force of 27 lbs. I've tried to read up a little on Hunter's website (the company that makes the RoadForce Balancing Machines) and I talked to the tech at the dealership and he said everything balanced out fine. I haven't driven the car enough yet to detect any problems or vibration and I'll report back on that later, but I just wondered if maybe one of the TIRERACK guys could chime in and let us all know what #'s are acceptable for a ROADFORCE BALANCE.
Thanks

VMRWheels · 06-30-2009, 04:11 PM

12lbs. is totally fine to be driven on, but the 27lbs. is a 1lb over what the recommend automobile road force should be. To be on the safe side, I would rotate the tire and rebalance it again.

-Charles@VMRWheels

Gary@TireRack · 06-30-2009, 04:16 PM

I've been told that it may vary by tire size, I'm having one of our most experienced balancing guys look into this further and let me know. Which size was it?

bimmer01 · 06-30-2009, 06:30 PM

Fronts are 225/40-18 and rears are 255/35-18
I had the rears done today, and they both came in at 10 lbs. I spoke with the area sales reps for the hunter machines, and he said all readings were within spec. I just wanted to get everyones thoughts. I still haven't driven enough to notice any problems yet.

Gary@TireRack · 07-01-2009, 09:02 AM

My tech guy was a little vague. He felt 25lbs was probably a vibe-free setup, but 35lbs 'might' have some vibration. Basically if a tire is in balance and there is no vibration, then getting it "more" in balance wouldn't make any difference.

Chico · 07-01-2009, 12:06 PM

Quote:

Originally Posted by bimmer01

I bought new General Exclaims form Tirerack and yesterday I had the fronts put on and roadforce balanced at the dealership. I'm going to do the rears today, I only crammed 2 in the car at a time to cut down on wear and tear

Anyway, I guess i just never realized that when you do a roadforce balance you get an actual # associated with each wheel in pounds of force. Probably no one bothered to actually give me those #'s in times past, so now I'm just curious as to exactly what they mean. Anyways, the driver's side front tire came out with a road force of 12 lbs. and the passenger front came in with a road force of 27 lbs. I've tried to read up a little on Hunter's website (the company that makes the RoadForce Balancing Machines) and I talked to the tech at the dealership and he said everything balanced out fine. I haven't driven the car enough yet to detect any problems or vibration and I'll report back on that later, but I just wondered if maybe one of the TIRERACK guys could chime in and let us all know what #'s are acceptable for a ROADFORCE BALANCE.
Thanks

27lbs is totally unacceptable and I would suggest getting a new tire. You many not notice much of vibration right now, but they get much worse as they wear over time.

bimmer01 · 07-01-2009, 09:14 PM

Just wanted to post a follow up, and let everyone know that I appreciate their inputs. Special thanks to Gary at tirerack. The car is riding great. No vibration what so ever. I notice a little more roadnoise at lower speeds with these tires, but thats another topic all together.
This is what the rep for Hunter had to say, "The numbers on the tires are both below acceptable tolerances. As far as the amount of weight on the wheel, rotating the tire to a new wheel position might reduce the amount of wheel weights but doesn't improve the balance of the assembly. Basically, fewer weights on the wheel is a cosmetic improvement, not a ride quality improvement. Hope this info helps. Let me know if I can be of further assistance."
Quickly, I'll try to explain what I've learned. What roadforce balancing does, is put the "high" spot of the wheel away from the "high" spot of the tire. On a "microscopic" level, wheels and tires are not round they have ridges and valleys or high spots and low spots. Evidently, perfectly true new factory wheels can be up to 9 thousands out of round. So, if the high spot on the wheel happened to be in line with the high spot on the tire, there could be a fairly significant, in terms of out of roundness although microscopic, "bulge" to the assembly. Anyway, a perfectly balanced wheel could have a high roadforce # because of this but unless you are getting a "roadforce" balance you would never know. So basically, you adjust the position of the tire relative to the wheel to get an acceptable number. I'm sure the lower the better, but exactly what is acceptable is the question. I hope this makes some sense, and maybe someone more knowledgable can chime in. But as Gary mentioned, if a wheel and tire assembly is "in balance" and performing satisfactory, it really doesn't make sense to "redo" it to make it better in terms of some theoretical #. I like to think that this is what the tire guy was thinking too???
Oh and by the way, the rears came in at 10 lbs each.

bimmer01 · 07-02-2009, 06:32 AM

I also found out that those annoying little colorful dots on new tires are put there in the manufacturing process to denote the "low" and "high" spots on the tire. As no tire is "perfectly" round, again on the "microscopic" level for lack of a better term. So when you buy a new car, and there is a freakin' sticker on your wheel and a dot on your tire, they were actually there for a very important purpose so that the "tire guy" could match the low spots and keep the high spots away from each other so that the roadforce number is as low as possible! Or, I guess a better explanation is to keep the roadforce number within spec, as what I am seeing is that if a wheel and tire combo "passes" on the machine, trying to lower the roadforce number arbitrarily just to get a lower number doesn't effect ride. I guess it's kinda like if you can hammer a nail with a regular hammer, using a sledgehammer would work, but it would provide no benefit. Just FYI, another practically useless fact I uncovered while reading about this stuff.

06-30-2009, 07:43 AM	#1
bimmer01 Private First Class 15 Rep 188 Posts Drives: 2008 328i Join Date: Jun 2009 Location: myrtle beach, sc iTrader: (4)	Question on roadforce balancing? I bought new General Exclaims form Tirerack and yesterday I had the fronts put on and roadforce balanced at the dealership. I'm going to do the rears today, I only crammed 2 in the car at a time to cut down on wear and tear Anyway, I guess i just never realized that when you do a roadforce balance you get an actual # associated with each wheel in pounds of force. Probably no one bothered to actually give me those #'s in times past, so now I'm just curious as to exactly what they mean. Anyways, the driver's side front tire came out with a road force of 12 lbs. and the passenger front came in with a road force of 27 lbs. I've tried to read up a little on Hunter's website (the company that makes the RoadForce Balancing Machines) and I talked to the tech at the dealership and he said everything balanced out fine. I haven't driven the car enough yet to detect any problems or vibration and I'll report back on that later, but I just wondered if maybe one of the TIRERACK guys could chime in and let us all know what #'s are acceptable for a ROADFORCE BALANCE. Thanks
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06-30-2009, 04:11 PM	#2
VMRWheels BimmerPost Supporting Vendor 2040 Rep 25,989 Posts Drives: BMW Join Date: Jun 2007 Location: Anaheim, CA iTrader: (4) Garage List 2013 BMW M3 [10.00] 2015 BMW M4 [0.00] 2013 BMW F30 [0.00] 2014 BMW F22 [0.00] 2013 BMW F06 [0.00]	12lbs. is totally fine to be driven on, but the 27lbs. is a 1lb over what the recommend automobile road force should be. To be on the safe side, I would rotate the tire and rebalance it again. -Charles@VMRWheels __________________ VMR\|Wheels \| 714.442.7916 \| sales@velocitymotoring.com \| www.velocitymotoring.com \| facebook \| flickr \| Instagram
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06-30-2009, 04:16 PM	#3
Gary@TireRack Moderator 369 Rep 4,745 Posts Drives: Formerly 1995 M3 Join Date: Oct 2006 Location: South Bend, IN, Tire Rack HQ iTrader: (2)	I've been told that it may vary by tire size, I'm having one of our most experienced balancing guys look into this further and let me know. Which size was it? __________________ Gary. Tire and Wheel Forum Moderator. Tire Rack Sales Rep Gary@Tirerack.com http://www.tirerack.com/a.jsp?a=AH8&url=index.jsp Please refer to 'Gary/E90 Post' as your previous contact when you order online to help support this forum.
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06-30-2009, 06:30 PM	#4
bimmer01 Private First Class 15 Rep 188 Posts Drives: 2008 328i Join Date: Jun 2009 Location: myrtle beach, sc iTrader: (4)	Fronts are 225/40-18 and rears are 255/35-18 I had the rears done today, and they both came in at 10 lbs. I spoke with the area sales reps for the hunter machines, and he said all readings were within spec. I just wanted to get everyones thoughts. I still haven't driven enough to notice any problems yet.
	Appreciate 0 Quote

07-01-2009, 09:02 AM	#5
Gary@TireRack Moderator 369 Rep 4,745 Posts Drives: Formerly 1995 M3 Join Date: Oct 2006 Location: South Bend, IN, Tire Rack HQ iTrader: (2)	My tech guy was a little vague. He felt 25lbs was probably a vibe-free setup, but 35lbs 'might' have some vibration. Basically if a tire is in balance and there is no vibration, then getting it "more" in balance wouldn't make any difference. __________________ Gary. Tire and Wheel Forum Moderator. Tire Rack Sales Rep Gary@Tirerack.com http://www.tirerack.com/a.jsp?a=AH8&url=index.jsp Please refer to 'Gary/E90 Post' as your previous contact when you order online to help support this forum.
	Appreciate 0 Quote

07-01-2009, 09:14 PM	#7
bimmer01 Private First Class 15 Rep 188 Posts Drives: 2008 328i Join Date: Jun 2009 Location: myrtle beach, sc iTrader: (4)	Just wanted to post a follow up, and let everyone know that I appreciate their inputs. Special thanks to Gary at tirerack. The car is riding great. No vibration what so ever. I notice a little more roadnoise at lower speeds with these tires, but thats another topic all together. This is what the rep for Hunter had to say, "The numbers on the tires are both below acceptable tolerances. As far as the amount of weight on the wheel, rotating the tire to a new wheel position might reduce the amount of wheel weights but doesn't improve the balance of the assembly. Basically, fewer weights on the wheel is a cosmetic improvement, not a ride quality improvement. Hope this info helps. Let me know if I can be of further assistance." Quickly, I'll try to explain what I've learned. What roadforce balancing does, is put the "high" spot of the wheel away from the "high" spot of the tire. On a "microscopic" level, wheels and tires are not round they have ridges and valleys or high spots and low spots. Evidently, perfectly true new factory wheels can be up to 9 thousands out of round. So, if the high spot on the wheel happened to be in line with the high spot on the tire, there could be a fairly significant, in terms of out of roundness although microscopic, "bulge" to the assembly. Anyway, a perfectly balanced wheel could have a high roadforce # because of this but unless you are getting a "roadforce" balance you would never know. So basically, you adjust the position of the tire relative to the wheel to get an acceptable number. I'm sure the lower the better, but exactly what is acceptable is the question. I hope this makes some sense, and maybe someone more knowledgable can chime in. But as Gary mentioned, if a wheel and tire assembly is "in balance" and performing satisfactory, it really doesn't make sense to "redo" it to make it better in terms of some theoretical #. I like to think that this is what the tire guy was thinking too??? Oh and by the way, the rears came in at 10 lbs each.
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07-02-2009, 06:32 AM	#8
bimmer01 Private First Class 15 Rep 188 Posts Drives: 2008 328i Join Date: Jun 2009 Location: myrtle beach, sc iTrader: (4)	I also found out that those annoying little colorful dots on new tires are put there in the manufacturing process to denote the "low" and "high" spots on the tire. As no tire is "perfectly" round, again on the "microscopic" level for lack of a better term. So when you buy a new car, and there is a freakin' sticker on your wheel and a dot on your tire, they were actually there for a very important purpose so that the "tire guy" could match the low spots and keep the high spots away from each other so that the roadforce number is as low as possible! Or, I guess a better explanation is to keep the roadforce number within spec, as what I am seeing is that if a wheel and tire combo "passes" on the machine, trying to lower the roadforce number arbitrarily just to get a lower number doesn't effect ride. I guess it's kinda like if you can hammer a nail with a regular hammer, using a sledgehammer would work, but it would provide no benefit. Just FYI, another practically useless fact I uncovered while reading about this stuff.
	Appreciate 0 Quote