Adopting NSC rules for wheels - Inspection Advice?

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Vitamin K
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Adopting NSC rules for wheels - Inspection Advice?

Post by Vitamin K » Mon Aug 17, 2015 7:59 am

Hello Derbians,

So after some discussion with the organizers at our District, I was able to make a successful case for adopting the Northern Star Council's rules on wheels and axles. Specifically, this means that the axles need to be metal, with a nail-type head (we can't inspect for anything more than that), and for the wheels (paraphrased):

- All lettering, numbering, spokes and fluting is present and visible.
- Wheel diameter is 1.16" mininum.
- Tread width is 7.5mm minimum, and flat and parallel to bore.
- No material removal from inside of tread.

Can anybody suggest a good process to follow to train inspectors to check wheels? I want to be able to give them good guidelines to follow, so that we do it in a consistent and efficient format. If anybody's been involved with tech-in at a NSC event, I'd like to hear from you even more.

It seems like you could do something like the following:

- Check for lettering/markings/etc.
- Use small flashlight to check inside of wheel for material removal.
- Slide go/no-go guage over wheel diameter to check for minimum diameter
- Slide a different go/no-go guage over wheel width to check for minimum width

Does this sound like a reasonable way to go? I'm a little worried about fenders making it harder to check the diameter of wheels, so I'm eager to hear how that's been dealt with in the past. Also, thoughts on 'aero shields' would be welcome as well.



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Stan Pope
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Re: Adopting NSC rules for wheels - Inspection Advice?

Post by Stan Pope » Mon Aug 17, 2015 6:44 pm

I prefer to use the minimum instrumentation possible while still maintaining reliable conformance. So, I would use an alternative specification for wheel diameter and tread width which depend on wheel aspects that even every Cub Scout can apply without help,
For instance, require that the flat of the tread not be narrower than an "out of the box" wheel and that wheel diameter reduction [(a)can not infringe on, (b) can not completely remove any of, or (c) must leave at least part of one of] the wheel "tread marks" or serrations. I would, personally, select one of the diameter limit above that does not match any commercially available wheel diameter! :)

My thinking for setting these type of rules is that most will not have access to precision measuring equipment and, so, can not work their wheels with confidence that they are staying within the rules. So, set the specs so that they can tell if they are getting close to the limit by looking at the wheel .. or comparing it to a new wheel.


Stan
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Re: Adopting NSC rules for wheels - Inspection Advice?

Post by LightninBoy » Tue Aug 18, 2015 10:51 pm

Vitamin K wrote:Hello Derbians,

So after some discussion with the organizers at our District, I was able to make a successful case for adopting the Northern Star Council's rules on wheels and axles. Specifically, this means that the axles need to be metal, with a nail-type head (we can't inspect for anything more than that), and for the wheels (paraphrased):
- All lettering, numbering, spokes and fluting is present and visible.
- Wheel diameter is 1.16" mininum.
- Tread width is 7.5mm minimum, and flat and parallel to bore.
- No material removal from inside of tread.

Can anybody suggest a good process to follow to train inspectors to check wheels? I want to be able to give them good guidelines to follow, so that we do it in a consistent and efficient format. If anybody's been involved with tech-in at a NSC event, I'd like to hear from you even more.

It seems like you could do something like the following:

- Check for lettering/markings/etc.
- Use small flashlight to check inside of wheel for material removal.
- Slide go/no-go guage over wheel diameter to check for minimum diameter
- Slide a different go/no-go guage over wheel width to check for minimum width

Does this sound like a reasonable way to go? I'm a little worried about fenders making it harder to check the diameter of wheels, so I'm eager to hear how that's been dealt with in the past. Also, thoughts on 'aero shields' would be welcome as well.
First - congrats on getting the rules relaxed!

To Stan's point, at 1.16 diameter is right about the point where the tread bumps are clearly visible. Go much lower, and the bumps disappear. That's the advantage of using 1.16 - the disadvantage is that I believe the go/no-go tools on the market assume 1.17.

I think the biggest help to inspectors is to provide them with examples of wheels that are illegal, and modified wheels that are legal, so that they can see the difference. That and a digital caliper should be all that's needed.

Consider posting this question at pwdracing.proboards.com. Warren has been enforcing the NSC rules for years and might have more to share.



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