Definition of Unicycle, and measuring of outside diameter of wheel (Closed for comments)

Comments about this discussion:


Under 1D.1, a sentence is included:

For any tire in question, its outside diameter must be accurately measured.

1. I believe this is incorrect. The only thing we need to do, and also do in practice, is to check whether the diameter is within the limit. We don't measure its diameter.
2. I'm not sure if this requirement must be under the definition of unicycle. It seems not part of the definition.
3. Wherever in the Rulebook we regulate this, I would add "under the conditions it will be used in the competition". That means notably the same tyre pressure, perhaps also the same temperature. If the wheel diameter is checked immediately before the race, as is usual, this becomes a non-issue. But this is not required by the rules.


I totally agree with you.

To 2.: I would also say, that's not a definition but I'm not sure if we have to add that on several places if we delete that from this point of the rulebook...


I understand your problem with 2. If you think creatively, the checking of the diameter can be under the definition (as it is now). E.g. a unicycle is only within the defined category after it is checked for diameter. Before it is checked, you don't know what it is.


Mostly, wheel diameter is a concern for Track events. The best easy way to measure wheels for Track is to make a box that you can stick the wheel in. There is no easy way to check a wheel's outside diameter otherwise; all "quick" methods have their downsides. It doesn't have to be a box, though, it could be a bracket, used in the same way as the box. The box idea is good because it's very sturdy, and not easily knocked out of calibration.

It's definitely not part of the definition of unicycle, and probably belongs in the sections where wheel sizes have limits.


I argued (and still argue) that it can be seen as part of the definition of "Unicycle, Wheel Size Classes". It's the easiest to keep the rule about the diameter in this place.


I agree with Klaas.


Yes, that sentence at the top of this discussion needs updating:

"Any wheels in question must be checked for compliance within their wheel class."

How about that? Possibly include a reference/link to where it describes how we check them.


Yes, something like that. And, as pointed out in the opening post, I would add "under the conditions it will be used in the competition".

I just noticed that 2B.2 has the same sentence. It must have the updates as well, but it's in a different committee. Hmmm. I'll propose it there too.


The sentence in question alse appears in the Track and Road chapter. I have made proposals in those subcommittees to edit the rule there. Assuming that those proposals pass, I think we don't need the rule about checking/measuring the diameter in 1D.1 - that sort of duplication is not good.

I therefore suggest that we delete it from iD.1. I will include this in a proposal emanating from Discussion 160.


Closing this discussion as the idea is included with Discussion 160 / Proposal 85.

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