Tips/Advice for Lug Centric Balancing?
Thread Starter
Burning Brakes
Joined: Oct 2009
Posts: 1,066
Likes: 57
Tips/Advice for Lug Centric Balancing?
I need to have a set of repro steel rims lug centric balanced.
The first reputable tire shop I took them to claimed that there was no difference between lug centric and hub centric balancing (turns out, they didn't have the 'finger' adapter plate for lug centric balancing on their machine). I went elsewhere.
The second tire shop I went to had the adapter, but I sensed they weren't quite sure how to use it. When the rims were spun up (without a tire mounted) to see how true they were, they looked out of round when using the lug centric finger adapter. Conversely, when spun up with the 'cone' adapter, they appeared more true.
Any suggestions?
Thanks
The first reputable tire shop I took them to claimed that there was no difference between lug centric and hub centric balancing (turns out, they didn't have the 'finger' adapter plate for lug centric balancing on their machine). I went elsewhere.
The second tire shop I went to had the adapter, but I sensed they weren't quite sure how to use it. When the rims were spun up (without a tire mounted) to see how true they were, they looked out of round when using the lug centric finger adapter. Conversely, when spun up with the 'cone' adapter, they appeared more true.
Any suggestions?
Thanks
Melting Slicks
Joined: Oct 2002
Posts: 2,317
Likes: 111
From: St Louis MO
Lug centric just adds another way for tolerances to accumulate and cause error - if at all possible, get wheels that are hub centric...
This reminds me of my old '78 Seville in which I had a right front wheel shimmy. Balancing did not help. When I added a set of new ARE alloy wheels and new tires (which balanced nicely - hub centric), I figured that the problem would go away, but it didn't. Since the wheels had a larger hub opening than the hub on the rotor, they were lug centric, and a dial indicator showed that the wheel runout was varying by ~.025". I re-clocked and shifted the rim slightly on the shouldered lug nuts, but it wasn't enough and I still had the shimmy (shocks, tie rods, idler arms were all good).
To troubleshoot further, I used an electric motor to spin up the rotor without the wheel on it - it was smooth and in balance. Finally, I measured the runout of each the studs from the rotational axis of the hub - it was out by .025"! Apparently, the stud bolt circle was NOT concentric with the hub's wheel bearing bores!
After I replaced the hub, everything ran smoothly.
This reminds me of my old '78 Seville in which I had a right front wheel shimmy. Balancing did not help. When I added a set of new ARE alloy wheels and new tires (which balanced nicely - hub centric), I figured that the problem would go away, but it didn't. Since the wheels had a larger hub opening than the hub on the rotor, they were lug centric, and a dial indicator showed that the wheel runout was varying by ~.025". I re-clocked and shifted the rim slightly on the shouldered lug nuts, but it wasn't enough and I still had the shimmy (shocks, tie rods, idler arms were all good).
To troubleshoot further, I used an electric motor to spin up the rotor without the wheel on it - it was smooth and in balance. Finally, I measured the runout of each the studs from the rotational axis of the hub - it was out by .025"! Apparently, the stud bolt circle was NOT concentric with the hub's wheel bearing bores!
After I replaced the hub, everything ran smoothly.
adapter, adaptor, balance, balancing, center, centric, concentirc, concentric, difference, hub, lug, lugcentric, plate, tire
