Rule 14B.2 Unicycles - Maximum Wheel Size Clarification

This discussion has an associated proposal. View Proposal Details here.

Comments about this discussion:



Ok, I'm not sure if I posted this correctly, so I've written it again:


'14B.2 Unicycles

Only standard unicycles may be used. The maximum wheel size is 618 mm (24”).'


The above rule states that the maximum wheel size to be used is 618mm. However, it also says 24" after. To my belief, most 24" muni's exceed the wheel size of 618mm. However, a 24" unicycle with a flat tyre is usually 618mm or under.


Maybe we could word this rule better so there is no confusion to which is the maximum size?


Perhaps we should take the 24" in brackets out. 24" inch in milimeteres is 609.6mm so it just looks stupid to have it there as it looks like we cant do conversions properly.

Also a 26inch rim with a tiny tyre is under 618mm is it not? meaning that you could use that in hockey if you wanted to.

There is no benefit to having 24" in the measurement, all it does is confuse matters and result in players not measuring their tyre as they assume because it is a 24" unicycle that it must be under 618mm.


Or is the option to increase the maximal diameter to a larger size like basketball? Finding tyres under 618mm is a hassle.


I'd be happy to get rid of this inconsistent mixture of 24" inch and 618

mm in the hockey rules. Unfortunately, this mix also appears at many

other places in the IUF rulebook. If we change it only for hockey, the

resulting rulebook will be even more inconsistent. I think the best

solution would be to move the discussion to the Main Committee.

Hopefully we can find a solution for all unicycle sports.



Ok, thanks Rolf.. I'll post it in there. Maybe you could comment on the discussion where the rest of the rules are? I only know the hockey one, and it's a pretty big document, ha!


The 618 mm are pretty much everywhere in the rulebook. Just search for
"618" in the pdf, and you'll find them...


Yes you will find 618mm mostly in according with racing. I guess more than 80% of the players on a 24" weal exceed 618mm. Key is to have a good grip. I have seen no referee on a UNICON or in the germane national league who checked the dimension of the weal of a hockey player. Normally we take no care and accept more or less all kinds of tyres which fit to a 24" rim (~ 507mm). Should we go to a rim size or the bigger wheel size like basketball?


I think we should consider allowing a bigger tyre. Purely to make it easier by not having to measure it? Everyone uses the same size rulebook so it's up to the player on what they want to use.


For the top players, I can see no problem with allowing big wheels.
However, I am afraid that inexperienced players would (mis-) use the big
wheel even though they are not able to control it properly during the
hockey game. If they are not able to stop, they will bump into the wall
or into other players. So for safety reasons I prefer to keep the
current size limit.


My gues in Germany only 5- max 7 % of the players ride a 24" for hockey, half of them are goalies. Minimum twice a year on a tournament a discussion starts to banish all 24" from the hockey field for safety reasons as Rolf described before. This discussions ends normally the the advice that there are exist a handful of players on 24" who have their 24" under fully control and the IUF rules allow to use 24" unicycles for hockey. I personal dislike 24" unis for hockey (but my dislike is in contrast to the rule). Was there any discussion on the wheel size for hockey years ago?




From my experience, people are just as likely to be knocked off by 20's as 24's. 

Most beginners I have seen on 24's are not able to get anywhere near enough speed to be a danger from not being able to stop. From what I have seen the skills of acceleration and moving your legs fast comes with the ability to stop them moving fast. I am yet to see a player who is skilled enough to ride quickly but cant stop.

Novice riders on 24's can't stop quickly but they also can't ride very quickly at all so it has never been an issue. Possibly crank length difference? All our 24 riders use 125s possibly your guys are using 114s?


Personally I think size difference of 24s have a tactical benefit in hockey teams in defence compared to 20s (similar that defence players in ice hockey use longer sticks and attackers use shorter) so I think it brings an interesting level of strategy and complexity to our game by having them.

Also the main rulebook committee appears to be going extremely slowly/nowhere in the decision of the 618mm wheel rule. As Mary Koehler said

I disagree that putting in size definitions in Chapter 1 is the best way to go. First, any exceptions cause confusion. For riders and officials this is stressful. Second, it seems like it is forcing you to find a size that can fit all disciplines. For example, Someone pointed out that hockey does not have a crank length limit, so that would be an exception. Describing the specifics of unicycle requirements for each discipline would also allow future flexibility.


We already have a difference in not having a set crank length, why not just use our own dimensions and ignore "standard unicycle"

What if the standard wheel size is changed to 700mm in two UNICONs time, then we would be forced to change our rules to move in line with this or change our rules to go away from a standard size. As she said this gives future flexibility for us in our rules without having to discuss "but the standard wheel size in IUF is ______"


I think we still should allow 24'' for the reasons Steven mentioned.

I think if we reword the rule it should be all clear:

The maximum rim size is 24'' with an tire of maximum 618 mm. OR

The maximum wheel has a rim size of 24'' and a tire of maximum 618 mm.


There is currently a big discussion in the IUF Main Committee (some of
you follow this discussion, some don't) and I don't expect any decision
soon. Until they find a solution that covers the whole IUF rulebook, I
think we should remove the inconsistent and confusing number 24" from
the hockey section and emphasize that the _outer_ diameter is meant:

OLD: The maximum wheel size is 618 mm (24").

NEW: The maximum outer diameter of the wheel is 618 mm.

I think we can safely refer to a "standard unicycle" as described in
section 1D.1. I like the definition that is given there because it does
not mention any wheel or crank size limits.


The IUF Main Committee is going too slowly, we will be lucky to have it sorted by next Unicon. We should fix the issue ourselves (there is no reason why Hockey Rules need to be an IUF thing at all.)

I agree we take out 24" and go with Rolf's  wording "The maximum outer diameter of the wheel is 618 mm."



The current wordings of standard unicycle and our rules are below.

Standard Unicycle Definition


Standard Unicycle: Has only one wheel. Is driven by crank arms directly attached to the wheel’s axle/hub, with no gearing or additional drive system. Pedals and cranks rotate to power the wheel. Is balanced and controlled by the rider only, with no additional support devices. Brakes and extended handles/handlebars are permitted. For some events, such as track racing, standard unicycles have restrictions on wheel size and/or crank arm length. Other events may specify other restrictions. When not noted otherwise, there are no size limitations.


Hockey Section

14B.2 Unicycles

Only standard unicycles may be used. The maximum wheel size is 618 mm (24”). The unicycles must not have sharp or protruding parts anywhere that might cause injuries. This refers especially to quick-release levers and bolts. The pedals must be plastic or rubber.



This is slightly confusing because if someone reads that standard unicycles are allowed it says that standard unicycles can have brakes and extended handles.



Could we re-word our section so people are more aware of the number of restrictions that we put on what a standard unicycle allows?


14B.2 Unicycles


Only standard unicycles that do not have sharp or protruding parts may be used. This refers especially to quick-release seat clamps and handlebars. The unicycle must also have plastic or rubber pedals. The maximum outer diameter of the wheel is 618 mm.





I think in reality nearly none took care on the dimension of a hockey wheel if it wasn't huge. Have you ever seen a gauge with the host or referees to measure the wheels?

I remember that a lot of French basketball player were in trouble with their dimension of their 24" unis where they tried to start for races. Their wheels (most times "halo twin rail") were not in gauge with 618mm. Is this the reason why basketball set their maximum wheel size to 640mm (25.2”)? (5B.2).

If we like to stick to measure the wheels the referee should have been provided a gauge and this measurement has to be written into 14C.2.5 (Before The Game) as a task for the referee.

Therefore I suggest again a bigger gauge than 618mm and nobody will measure it because nobody has an interest to measure.





> Therefore I suggest again a bigger gauge than 618mm and nobody will
> measure it because nobody has an interest to measure.

Herbert, I fear that your new rule will not solve the problem but only
shift it. Right now, we have a problem if someone has a 619 mm wheel and
we need to measure it. This problem will be solved when we change the
maximum wheel size to 640 mm. However, then we will have someone with a
641 mm unicycle and the same problem again.


For the moment I assume that more than 50% of the players on 24" wheels are riding to big tyres. They use tyres which suit for gym and not for track. When we set the maximum size to e.g. 640mmm (from basketball) I guess this would cover more than 90 % of the tyres all team sports use in gym and what is to buy. (Only in a big doubt I would measure.) I agree all fixed dimensions will erase sometimes problems, with a bigger dimension I like to reduce this matter to a minimum and no normal need for a gauge.

If your intentions is to avoid 24"-wheels from hockey (I individually dislike 24"-wheel in hockey anyway) stick to 618mm, but there is a strong need that the host provides a gauge to the board of referees for the measurement.

"Are the unicycles and sticks orderly" (14C.2.5 Before The Game) would cover the measurement if someone is in doubt anyway.


Maybe the IUF should provide a list of common 24" tyres 1. column "there is no doubt that they fit to 618mm" 2. column in doubt, must be measured and 3. column "without no doubt these tyres are to big". The dealers e.g. from (they cover more or less the world market) may help.




In Australia all riders who ride 24's use legal tyres as we follow the rules closely. I assume in the teams in your leagues where players take hockey seriously they also have legal tyres. From what I have seen the only players who have illegal wheels are ones who dont do hockey much and use their 24 for other things like muni or road riding.

In response to increasing the size I believe most players would not try and use the biggest tyre possible except for goalkeepers. I am not against increasing the size however we would still need to measure as goalies would be the ones trying to get tyres as close as possible to the new size. One argument for increasing the size to the same as basketball size however is to increase participation of Hockey. Having basketball players able to compete without changing wheel may improve the chances of ever starting a real hockey league in France.

I think a list of tyres is difficult as the diameter is not given by manufacturers so it really must be measured, this can be a hassle to set up.

The host should provide a box for measurement but measuring tyres every time a team goes on is also a hassle. I have other ideas to ensure the enforcement of this rule at next unicon which will make it much easier for the director/referees, a box would still be required, but rarely needed.



Whatever dimension here will be agreed, I would like to know your ideas to ensure this rule now!


Before a tournament all competing teams must complete an online statutory declaration stating that all riders on their teams will be using legal wheel set under XXXmm in diameter and that if any people at the tournament suspect a tyre they are using to be over this time they must measure it in the provided wheel box. They also agree that if the wheel is found to be over the legal size they will forfeit that match.

This way

1. They have agreed BEFOREHAND to ensure their tyre is legal.

2. They have agreed they will check a tyre (in front of director or refs) that is questioned by ANY person at the venue; opposing team, other teams, officials, spectators

3. They have agreed that they will forfeit the match that it was seen being used in if it is found to be illegal.


This ensures no team can say they were not aware of the dimensions, it creates a harsh penalty that any competitive team cannot afford to have if they plan to win, it also enables the policing of tyres to be undertaken by everyone at a venue decreasing strain on directors and referees. 


Have all team declarations available on a google drive to all teams so no team can claim they didn't know. A box must be present at the event for this to work but it should fix 99.9% of oversized wheels, the only ones who may risk it are likely to be teams who are not seriously competitive and can afford to forfeit a match.


I propose we do something similar for "players playing on multiple teams" 


I think in general we need to have more communication between teams and the person running it using an online forum/group prior to Unicon as well as during the event. That way the director can easily get out messages to people even when not at the venue not at tournament meetings. Anyway I guess this is another subject and I will avoid hijacking this thread. I believe all who are on the rule committee should keep in contact to discuss how things can be best run especially if Rolf says he won't be doing next unicon.


So no update to this.


Can we come to a general consensus?


1.A.   Change the wording of maximum outer diameter to 618. Ignore the 24" that is used currently and futureproof our rulebook against IUF changes.

1.B    Change nothing



2.A.   Change the size to basketball size to try and increase participation??
2.B.    Keep the same size


For the first topic, I prefer 1A:

OLD: The maximum wheel size is 618 mm (24").

NEW: The maximum outer diameter of the wheel is 618 mm.

For the second topic, I prefer 2B, keeping the size limit as it is now.


I prefer 


1A "The maximum outer diameter of the wheel is 618 mm."


I prefer 

2A, increase size (as I would love to see the ability for more crossover for basketballers) but if no one else wants it I am fine with with keeping the same size.


I prefer :

1A and 2A.

I think the size should stay as it is for now.. Maybe if basketballers show interest at the next Unicon, we could consider it.


You meant 2B, Gareth?


I see there is no chance to get red of the 24" wheels.

Therefore I prefer 1A in combination with 2A.


I like Stevens´s idea with the declaration beforehand, maybe done by the team captain for his team. > open a new discussion.

But, here a big but "forfeit a match" would be a new team punishment what we never discussed before. > open a new discussion (The ongoing discussion "penalties" will not suit.)


I prefer 1A and 2A.

I like very much Steven's idea about the declaration beforehand.

If we do something like this I would extend this to the hockey sticks. We had an issue about the shaft of the hockey stick (aluminium shaft which is not legal).


Regarding the first question, it looks like we all agree on 1A:

OLD: The maximum wheel size is 618 mm (24").

NEW: The maximum outer diameter of the wheel is 618 mm.

Regarding the second question, there are several pros and cons for
increasing the limit to 640 mm:

PRO: Same as for basketball, allows basketball people with big wheels to
     participate in hockey games.

PRO: Makes it easier to allow a wheel without a careful check if the
     diameter is very close to 618 mm.

CON: Does not solve the general problem that some tires are just a
     little bit above the limit. The new limit would make 26x1.50 legal
     (639.8 mm) but 26x1.75 would still be illegal (643.9 mm), as you
     can check here:

CON: Not consistent with IUF definition of the 24 class.


As long as the outer diameter is below a certain measurement I have no issue with a 26x1.5 being legal. The outer diameter is the same and I think using something so thin for hockey would be a negative. If people want to do it that doesn't bother me. I'm not as fussed with what size the rim is rather the total outer diameter.

We are already not consistent with the 24" class in IUF as they have crank limitations. I have had people think before that we have a limit of 125s on 24s because they mistake our 24 regulations for the IUF 24 regulation


Any other comments so we can bring this to a proposal?


A big 24x2.125 would be legal for hockey. The 26x1.50 wheel will be expensive, I don´t believe that somebody would risk to play hockey with. In this seldom case trying to play on a 26 rim I would ask for a measurement.


OLD: The maximum wheel size is 618 mm (24").

NEW: The maximum outer diameter of the wheel is 640 mm.


I think that we all agree to use the phrase "The maximum outer diameter
of the wheel is 6xx mm" but we have different opinions regarding 618 or
640 mm. I don't want to risk that the proposal fails completely so I
suggest that we make two separate votes: One for the improved text, and
one for changing the size limit. I can create a proposal from this
discussion for the improved text (adding "outer" and removing the 24).

Steven, if you want, you can start a new discussion "increasing the wheel
size from 618 to 640 mm" and create an associated proposal. Then we can
vote on that separately.


Ok Rolf will do


Thanks Rolf


I had a view at the running Proposal 61: Unicycle wheel size (Main Committee). We need a better clarification for our unicycles allowed to be used for hockey, we have no unicycle classes and no wheel class therefore no standard unicycle. "The maximum outer diameter of the wheel" is not enough. Somewhere we should read that we have no crank arm length limitation. And we should write that we don't like to see geared wheels.

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