Wheel clearance

[Colibri]

On the wheel alignment tool, there is a part for wheel clearance. On the tool it’s 1/32. What distance do you set your wheel clearance?

[Stan Pope]

On the wheel alignment tool, there is a part for wheel clearance. On the tool it’s 1/32. What distance do you set your wheel clearance?

Excellent question. The answer boils down to WHY you want a specific "clearance."

Just to make sure, we are talking about the distance between the car body and the wheel hub face when the wheel is touching the nail head. Right?

Some folks say to make it small, 1/32" or less, apparently to prevent the wheel from twisting on the axle when it runs over a rough spot on the track. There is some play between the axle and the bore, and the wheel could deflect a bit off course.

I don't necessarily disagree with them, but I have better use for the ability of the wheel to slide in and out on the axle: It is a highly sensitive indicator of alignment that does not depend on expensive instrumentation. It is so valuable to me that I will shave a few fractions of an inch off the side of the block (after drilling the axle holes) to get from 1/10" to 1/8" of clearance. (Note that when the new shallow-well wheels came out, one could no longer get that much clearance with the original body width!)

[Colibri]

“Just to make sure, we are talking about the distance between the car body and the wheel hub face when the wheel is touching the nail head. Right?”

You are correct. I realized after I had posted my question that my wording of the question might be misunderstood.

[RACER X]

We have found that more is better also.

Last year we tested this on several cars with the same results on all of them on a timer.

Just like Stan, we found that around 1/10" to 1/8" hub to body clearance performed best. Anything less or more seemed to be slower and less consistant.

[Stan Pope]

We have found that more is better also.

Last year we tested this on several cars with the same results on all of them on a timer.

Just like Stan, we found that around 1/10" to 1/8" hub to body clearance performed best. Anything less or more seemed to be slower and less consistant.

When you did these tests, did you make adjustments so that the overall car width stayed constant? Or did you allow tha width to increase as the clearance increased?

There is belief in some circles that "wider is better". It is probably true if alignment stays correct and if the Cub can stage the car optimally. As clearance increases, there is less axle in the wood, which may alter alignment and the ability to stay aligned.

The usual 2 3/4" width limit is there to put a limit on "wider."