Wheel width

[Colibri]

I’ve read that people are concerned about rubbing the wheels on the center rail. What if you expanded the distance between the wheels so the outside of the wheels are it the limit of the width rule. This would move the wheels away from the center rail and give more room.

[Da Graphite Kid]

Colibri, this sounds like a good idea as long as you race on a track that has no side rails or that is unusually wide. I can't remember how wide a 'standard' (as if there is such a thing) is but I would suspect that this design would now cause the "rubbing" to occur on the outside rails. I have read that with unmodified BSA wheels (raised letters still present) that the car will be more likely to ride up on the outside rail. Seems like this would do more to slow a pwd car down than rubbing on the inside guide rail. If you look at a BSA wheel, it seems (to me at least) that they were designed to run on a center guided track as the inside end is flat.

What does everyone else think?

Da Graphite Kid

[MaxV]

The added freeplay would increase the distance the car has to travel.

Think of a car with bad alignment; it constantly goes back and forth restricted by the lane guide. The wider apart the wheels, the further the car deviates from a straight line, and the further it travels. Even a well-aligned car will hit the guide rail once or twice, so wider wheel spacing will effect it negatively as well.

[PWD]

Max-V I don't know if I completely buy into your thinking. The other side is the lost energy actually hitting the lane guide. I think a car would be faster that swayed back and forth but never hit the guide rail compared to a car that hit the guide rail over and over again.

Obviously the best would be a car that went straight and never hit the guide rail.

What if you had a car that went all the way down and never hit anything the lane guide and then right at the end hit it. If there were more room and made it to the end without hitting the lane guide it would be better, IMO.

-SP-

[TurtlePowered]

I would agree that wider wheel placement can help but only if you get the axels almost perfectly alligned. You might want to check out Stan Pope's LMZ (or something like that) shimming techniques!

[Stan Pope]

Most local Cub Scout rules limit the overall car width to 2 3/4 inches. With a stock pinewood block, this limit does not permit much play on the axles.

The usual advantage associated with a wider car is that it delays the first impact with the center rail, and, hopefully, delays subsequent impacts. The delayed impact is believed to confer more advantage than the reduced travel distance forced by narrow axles.

Your best strategy, regardless of wheel separation, is to have excellent alignment and, so, minimize the guide rail impact ssue, and to treat the inner face of the wheel rim so that when/if impact occurs, it is less significant.

[MaxV]

Max-V I don't know if I completely buy into your thinking. The other side is the lost energy actually hitting the lane guide. I think a car would be faster that swayed back and forth but never hit the guide rail compared to a car that hit the guide rail over and over again.

I have never seen a car that swayed back and forth without hitting the guide rail.

Clearly, hitting the guide rail is bad. As you indicate the best is to not hit the guide rail. But if a car is going to hit the guide rail once or twice, then it is best for the car to travel the shortest possible distance to do so.