Wheel Test Question

[ZiggyDude]

There is a test that my son and I have been doing for wheels. We would get a perfect smooth surface like a kitchen counter, clean and ready it, then build a small ramp. Maybe lift the high end 1/4".

We would then roll the wheels off and record which went the farthest and straightest. Over time we also started listening for the smoothest sound.

They all veer to the side of the hub - but some consistently go much farther than others. Those are the wheels that we would take for bore buffing. I have not been doing any truing (long story). Our results are that we have dominated in the pack but results in the districts have varied.

This year I was curious and got a set of wheels that were listed as "Lightly machined". They were trued and bore inspected.

I did my roll test with these wheels and they were among the worst of any. I was quite surprised.

I did actually put the wheels on a car and they were as fast as any of my best.

Is the test I mentioned useless?

My thanks in advance for your answers.

 

[bracketracer]

I would answer your question with a question-
Is it better to test a part in the manner in which it will be raced or in a manner completely different from how it's raced?

 

[jatofau1]

I concur. The true validation is having a wheels on the car. Rolling the wheels alone will not tell you how the wheels perform on a car. Some guys use their tuning board to get an idea if the car is rolling faster. Even when the wheels are on the car there are so many parameters that impact speed. Try to keep everything as consistent as possible when testing.

What I do is build several cars at a time. I run a test on one car until I get the best time out of it. Than I tune the other cars to see if I can make them faster. If I get the other ones faster, I will eventually try to retune the slower cars of the bunch.

It is time consuming but well worth your time. You will learn a lot from tuning multiple cars at once so you can see any incremental improvements and learn what seems to work. Also note that what works for one car may not work for others. Good luck with the testing.

 

[ZiggyDude]

My thanks to all replies.

I agree with the tuning advice. Never touch your fastest car. Currently we build three a year.

Though I consider myself a newbie at Pinewood - I am an experienced slot car racer. I think that is what helped me when we first started. One mentor (called by many as "The Frenchman") drilled in me that "if you want a perfect race then you need a perfect car." Making something "Good Enough" was the path to defeat. So, we looked for the closest to a perfect wheel. (Our first year we won the Tiger den, second in pack, second Tiger in districts.)

I guess I was wondering if the test we did was something that is done by others or not. Results of such. Why the machined wheel did so bad.

 

[bracketracer]

Why the machined wheel did so bad.

You said "they were as fast as any of my best." It doesn't sound like the machined wheels did too bad?

The idea behind machining a wheel is that you take a so-so wheel and improve it. You might make it as fast, not necessarily faster than the best un-machined wheel, though, especially if you didn't appreciably remove weight.

If you were searching for a better way to test individual wheels, you might look here:

http://pinewoodderbyonline.com/threads/how-do-you-know-where-you-are.1343/#post-12027

 

[HurriCrane Racing]

I would say that your test method has little useful information. If you want to be competitive in the district races and maybe the pro level, you will need to run canted rears. This will cause the wheels to ride on the edges. Your test is with the wheels running flat. Just not a good comparison.

I would suggest making a run out gauge if you are going to run scout wheels. This will let you quantify the quality of the wheels.

 

[ZiggyDude]

Interesting. Once again thank you.

So, it sounds like my test was good for finding out of round and bumpy wheels and that was about it. The point about riding on the edge is good. Saved me from crap wheels when I was using out of the tube. But that is about the end of it.

Sounds like you need the machines that the better suppliers have. Not surprising.

BrakeTracer - I tried your link but there was just a picture of goops and lotions. Sorry

 

[speed bump]

This might b off subject but here it goes. I built a test car ran it and tuned it for the fastest times it would run. Then I take off the back wheels and replace with another set of wheels. Run car again and see what time it post. I leave the steer alone so that is a constant variable. I have found some wheels to b better than others with this test. Just remember I am not a very fast racer either so this might not b a help.

 

[bracketracer]

BrakeTracer - I tried your link but there was just a picture of goops and lotions. Sorry

Did you scroll to the top of the linked thread ZiggyDude? It's the very first post in the thread. The old posts here don't have individual tags.

 

[Mojo Racing]

This might b off subject but here it goes. I built a test car ran it and tuned it for the fastest times it would run. Then I take off the back wheels and replace with another set of wheels. Run car again and see what time it post. I leave the steer alone so that is a constant variable. I have found some wheels to b better than others with this test. Just remember I am not a very fast racer either so this might not b a help.

Hey Speed Bump,

That is a good way to check things out on your cars... You have a good constant with the front end, so don't touch it. Put the other wheels on the rears and you will know if there is a difference in your car's performance.

 

[ZiggyDude]

My thanks to all that wrote and helped out.