The Great Debate: Wheel Adapters & Wheel Bearings

I've been running adapters for almost 10 years. No issues.

I think results vary and depend almost completely on:

Offset / Backspacing
Hub-Centric / Not
Driving Style

I like deep dish wheels, that have a smaller backspacing. Typically called a RWD offset wheel. This moves the weight distribution towards the center of the rim instead of the outer edge as seen on many FWD offset wheels. Newer cars, even RWD, tend to have the larger backspacing. Maybe the larger the backspacing, the more likely bearing wear will be.

There are two different kinds of adapters. Hub-centric are machined to fit spot on over the lip on the outer edge of the hub. This perfectly centers the adapter and puts the bulk of the weight on the hub itself instead of the studs...which are further from center on the hub. That too could contribute to bearing wear.

Finally, driving style. I'm a cruiser. I like torque, medium speeds, and mildly curvy to straight roads. I'm easier on my suspension and bearings because I am not an aggressive twisty high speed autocross driver. I think the more aggressive a driver is in turns, affects the wear of the bearings, and in turn, other suspension components.

This is a fun topic, there's so many logical answers

didya know that many high level drag cars of the rail and flopper variety run adapters? Look in the pits at your next event, pay attention when the wheels are off. They're all over. Here's a place that makes em

http://www.wheeladapter.com/index.php

But moving beyond the quality of the spacer, what about bearing geometry/loading for a corner carver?......

One might say that trips to steak houses and strip clubs isn't going to be as hard on a C3 as the track use they were designed for. (although the trip home from the strip club could be another story) So the bearings are able to take that punishment in the form of poor geometry instead of sustained lateral Gs.

Others might point out that we cheer anyone with 10-12" deep dish old-school wheels, and they're also horrible for bearing geometry/load. If we'd had the internets in the 80s this thread would be about deep dish cragars eating up wheel bearings on daily drivers.

To me, the real catch of spacers is the need to remove the wheel to check spacer torque. That's probably to blame for more spacer failures than anything else.

I think the popularity of dubs has created more high quality spacer options for musclecar enthusiasts but also opened the floodgates for cheap chineese junk. Don't be the guy who'll only spend 80 on a set of spacers then complains their junk. Of course they are.

Counterpoints please..... :cheers:

lsejlowe said:

I've heard that adapters are fine so long as your 'vette isn't silver...

Click to expand...

:laughing:

Good thing mine's pewter now then. :laughing:

All I know is everybody has an opinion on them.
Yet NOBODY has any proven tests.

Here's what I DO know:
Those that are afraid of them, despise them.
Those with no experience with them, have the largest opinion.
Those that use them, have no issue with them.

Complaints (or rumor) of failure are few and far between.
Out of those that experienced bearing failure....how do you verify the bearings where not aged and ready to fail already or wheren't cheap offshore parts?

This thread will be nothing but opinions and arguement because the only way to confirm if there is any issue with adapters would be to build brand new arms with all new identical quality parts and reconstruct testing over and over to confirm the validity of the parts wether they fail or not....and no one is going to do that.

My opinion.....any additional wear to the bearings or arms from using adapters would be so minimal over time that you would not know if bearing failure was due to the use of adapters or just normal failure. Moving the wheel mounting surface outward an inch or two is not going to produce the kind of force needed to cause premature bearing failure. (Not to mention my C6 wheel/tire combo is lighter than my old stock wheels-less sprung weight)

Now if my bearings fail within the next year, I may change my opinion on that.

lsejlowe said:

seems like this topic comes up every time someone puts a set of adapters on their C3 to use a later Corvette wheel. Some guys have run adapters for thousands of miles with no trouble and other guys swear up and down that you won't make it out of your driveway before you have issues. Here's a really rough cross section of a stock wheel and a large backspace wheel on a stock hub and spindle. What's your take and why?

Click to expand...

You have to make that call on your own based on your current Corvette.

The variables of Moment (spacer size 1/2"?, 2"?, 3"), amount of torque being delivered to the wheels (stock motor?, aftermarked crate?), and the age of your current bearings, how often you drive it, all come in to play.

The bigger the moment (more spacer you use), and the greater the torque = the more risk you have of bearing failure.

For example.....

My 1979's rear leaf spring is nearing the end of it's life. I can see some tilt inward of the rear wheels. So I know the bearings are already seeing some stress. I've also recently dropped in a new Crate 355 engine with 190 ft-lbs MORE torque than the stock engine....

If I go and add 2-inch spacers to the mix I'll be upping the moment arm on the bearings by a factor of about 17%. (2"/12" = 0.1666')

So now I've added 17% more moment arm to the bearings, added 190 ft-lbs of more toqure to the bearings, and I know my leaf springs got a sag as well also adding more stress to the bearings.

For me, I'd say it'd be a medium risk of bearing failure.