Unicon 20 France - Road Climbing Categories

I’m assuming one can register for unlimited and ride a 29".
On the other hand, would a 29" class rider be able to be promoted to “unlimited” depending on results?

For example:
Unlimited Class times:
1st:… 36", 50 minutes
2nd:. 36", 51 minutes

xth:… 29", 53 minutes
29" Class times:
1st:… 29", 52 minutes

Personally, if I were the 29" registered in the Unlimited Class, I’d do so hoping to be to compete against everyone. If I then get xth place in the Unlimited Class, but one person in the 29" Class is faster, I think getting (xth + 1) place is more reasonable.

Also, I’m guessing a majority of riders will not be faster if using something larger than an ungeared 29". Thus, the reason to have categories is unclear to me.

What do we know about the course for this event? I’m very interested in it because it’s something new. Do we know distance, how much elevation gain, how steep, etc.?

As to being “promoted” I doubt it. You compete in the class in which you enter. You have chosen to compete with larger wheels & geared hubs, or to compete with wheels like yours. Therefore, knowing the specs of the course are very important! I assume your 29" is ungeared, otherwise you would have to enter as Unlimited.

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As far as I know it is 15 km long, with 990 meters of elevation (yes, it is a shame that they didn’t put the 10 missing meters)

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This strava segment, but the last few meters are different.

Yes, I am planning on using an ungeared 29". For a while I had thought of using a geared 700C as my latest experience with Mt. Diablo showed it was better for that course. But now, I don’t think I’m fit enough to use the geared anymore…

Personally, I want to “compete” with the fastest riders. Regardless of what size unicycle/hub they are using and what size I use. This seems to point me towards registering in unlimited. But the “what if” is if someone in 29 Class is even faster!

Well, nobody can stop you from putting the data across the classes together so you can see where you stack up time wise across all participants…
I don’t anyone quite knows what kind of setup will be fastest, which is why they chose to apply the standard road race categories.

Yup! (Which is what I meant to convey when I said “compete” in quotes)

I see that in marathon races, having the 29" classes makes sense since

  1. A lot of people only have this or smaller sized unicycles with them at conventions
  2. I’d guess that many riders would be faster if they had access to a geared 29/36er. Because they don’t have one, having a 29" class lets there be a fair playing field.

So I guess that answers my questions since it also applies to this climbing race.

Though, (2) is a smaller percentage of people though for the climbing race compared to normal road races. My back of the napkin calculation says that maybe 10% of bicyclists on strava, would find a 29er to be a limiting factor, and would be faster on a bigger wheel/geared hub if available. While, I’m guessing 90%+ of riders would find the 29" size to be a limiting factor for a flat-ish marathon course.

Would the whole race be a mass start with all riders? I have no idea.

I had some information and exchanges about this race. We discussed it on the French forum:

I understood that the position of the race director @GizmoDuck is to make 2 separate categories. Indeed today we don’t know if the 29" is a size that limits the performance.

What I would find a pity is that because of this unknown, it is necessary to make 2 starts and thus 2 races. To know more, we would need to have an idea of the number of participants.

I have also discussed with @makym . He suggests to make a workshop / debate during the UNICON to make a decision together.

Maybe we can already start here :slight_smile:

I will race with an ungeared 36", I think I will be faster than a 29", but I am not sure (I never ride ungeared 29" ). But if there are 90% of the participants in standard (which should be about the case), I would be disappointed to race with only a small part of the participants.

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These are all interesting questions because this is a completely new event, at least for Unicon. All past Road races have been assumed to be “relatively” flat, meaning no significant changes in elevation. As this one tests riders’ Road climbing abilities, the answer to the equipment question is unknown. Even for Mt. Diablo, which has had lots of “data” collected over the years by unicyclists, the answer is unclear, between super-lightened 36ers vs. 700c with shorter cranks.

I do have a bit of anecdotal info about climbing Mt. Diablo. We did a Mt. Diablo climb during the run-up to Ride The Lobster, with a fairly large group of people. I ended up riding about the same speed as Mike Scalisi, and we experimented by switching between my 36" (Coker but with alloy rim/150s) and his 29" (shorter cranks). Our conclusion, which was based on riding a section on the upper (steeper) part of the climb was that the 36" was faster based on covering more ground per pedal stroke. We were both reduced to going “one crank at a time” (neither of us being huge hill-climb fans), so at that slow rhythm, the 36" came out superior due to a manageable cadence covering more ground. Not a scientific comparison by any means, but if a rider is reduced to a low speed, the larger wheel will likely do better.

Our Road racing equipment categories were also developed with flat courses in mind. The flatter the course, the larger advantage you get with a bigger wheel. As the course gets steeper, the advantage is lessened. The greater weight of the larger wheel becomes more of a factor as well.

The purpose of those categories is to allow people to compete against similar equipment. Especially at international events, where riders often are not free to bring a wide range of unicycles. Or they simply don’t own them. So the different categories were designed to allow smaller and/or slower unicycles to also race against each other.

So for this race it’s a toss-up on which category will be faster. Exciting! I assume you can only win medals for the category in which you entered. But both categories are equal to themselves. In the end, you can compare the data across all categories to see who did what with what.

That is most likely a logistical question. Unicon being large, especially when in Europe, there may be big groups for both categories. There were literally hundreds of riders signed up for the 10k at Unicon 18, which made for 20+ start groups. So they will likely have to start separately for safety, and to not disadvantage people starting at the back of a big group.

I suppose a bigger question will be which group should start first? I’m betting it will be the unlimiteds; people who are pretty sure they have the fastest setup they could possibly assemble.

I agree with Ken Looi, a seasoned Road racer, in that those groups should be separate. This would be more “fair” (I always put fair in quotes; fair is relative). While we don’t know which group will be faster, it will be more apples to apples. Also I think I agree with Ken that 36" will turn out to be the faster category, but this can only be guessed. Average grade of the course is 6.4" but some of it will be flatter and some will be steeper. A different mountain road could have different results even if it has the same amount of total climbing!

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The course is 15 km long with 950 m elevation gain. I rode the course together with Simon Jan and I didn’t notice downhill parts. It is mostly same grade inclination, with few flattish parts but that’s not significant.

In my opinion there is no advantage on wheels bigger than 29. Personally, I will change my category from unlimited to standard, although I believe that categories should not exist in this race. Also, I believe that in this particular race, the geared hub is disadvantage.

I support as follow:

  1. No categories related to gear
  2. when having categories “standard 29” and “unlimited” than the “standard 29” competitors should be placed and awarded in both categories (“standard 29” and “unlimited”) because the unlimited (it’s everything).

I do not support of having separate “standard 29” and “unlimited” categories because the race will not point out the best road climbing performer.

The reason of having two categories in marathon and 10k, or generally on flat courses is that geared and bigger wheel unicycles are faster and have undue advantage over standard 29 or 24 wheels. This could be the case on uphill race with downhill and flat sections but in this particular course it’s not.

This race is not regulated by the IUF Rulebook, thus it’s up to the organizer (or race director) to decide on how to run the event, but nevertheless they should follow opinion of the competitors.
I already spoke with race director Ken Looi and we didn’t agree. I am much often around unlimited riders, while Ken is more along standard riders. Thus, our opinions are shaped differently. I believe that the most democratic solution will be to meet with best 10 standard and unlimited riders after Marathon race and discuss on how to run the road uphill.

From technical point of view: The road traffic will be open, this will make a difficult and dangerous to make a mass start. Not sure what are the plans, but starting in groups will likely be necessary. If there is a starting in groups I don’t see a reason of not being able to register in two categories simultaneously ( if categories are maintained I would like to register myself in standard 29 and unlimited category :smiley: ). Starting in groups will make a difficult to see the placing during the race. With electronic time measuring I suggest to make control points on the course with the display showing the placing at the current position. This doesn’t seem to be difficult.


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I was trying to figure out how steep this is.

Anyway, at this moment, I don’t think I’d enjoy that race one bit (well, maybe I would as a spectator). :slight_smile:

Glad that there has been discussion already on the French forum and with Ken.

Here’s a quick chart showing cadence for different wheels, given various fitness levels.

Maybe this would be useful for anyone who doesn’t know what size wheel to use.
For example, I know my cycling fitness is “good”. Thus, a 29er with high rpm (short cranks), or 36er with mid rpm (medium length cranks), are both ok choices for me.

If someone isn’t sure, then maybe this distribution showing cyclists power/weight ratio might help with estimating.

Looking at it this way, there likely is a group of people (Very good and up) who “need” a geared or 36er to optimize their time.

One other point is that there’s even an IUF rule that says ungeared riders in unlimited road races can get their own awards.

3D.6 Ungeared Awards
At Unicon, if there are five or more geared male riders in an Unlimited event, the fastest three ungeared male riders will be awarded with an ungeared title for that event. Similarly, if there are five or more geared female riders in an Unlimited event at Unicon, the fastest three ungeared female riders will be awarded with an ungeared title for that event. This is only for the overall classification, not for Age Groups. Other events can choose to award the fastest three, one, or none of the ungeared riders as they wish.

This rule was made, I’m assuming, because ungeared 29/36 are much harder to go fast on than G29/G36 on flat routes, like you mentioned.

In this climbing race, I might even want to argue it should be the other way around. If there are mostly ungeared riders, then the few brave ones to ride geared up should get their own awards! (Half joking…)

I also think having 29 as a category, or any other size, is okay.
However, my proposal is that the categories are exclusive (distinct).
For example, there is a 29 and under class 29, which is distinct from an “unlimited” class which excludes 29 and smaller. Then, there is the overall race that includes everyone.

This is similar to age groups.

20+ age group might be fastest given human physiology. Someone in a 0-19 category, isn’t forced to choose if they are in an 0-19 or "unlimited’ age group. Everyone is in a distinct age group. Then, there are the overall winners, which can come from any age group.

That would be very cool!

One interesting other use case of the spreadsheet is to visualize stats for other courses too. A flat marathon course requires little power compared to the uphill race, unless you are on a geared 36. Every other size is basically spinning super fast. An ungeared 36er doesn’t make it onto the men’s chart until 152rpm… Thus, it makes sense the there is a 29" class that tests “spinning” as a skill for flat races.


Makym has a point here. At best, the “value” of a larger but heavier wheel are in question in this race, so the normal categories are not a good fit. Possibly an easier solution is to just have a category that is 29" and up. If anything, riders should maybe get extra credit for hauling a Schlumpf hub up the mountain. Because this course is reported to be a very steady, nearly constant uphill, maybe we should separate geared from ungeared, and leave it at that.

So you would have:

  • Unlimited Wheel Size (29" and up)
  • Geared; meaning any kind of legal gearing system; I may be wrong, but I believe chain drives are allowed in the normal Unlimited category
  • 24" or any smaller wheel size limit that’s allowed to enter, also with no crank restrictions because this is a new type of race

Riders would still have to pick one category, but there is not the assumption of one group being faster than the other.

The rule for ungeared winners should probably not apply for this race, since the geared hubs may well be a disadvantage.


I love numbers and data, but you are a real crazy! :crazy_face:

It’s interesting, but you consider that we are only machines to produce watts? :sweat_smile:

The unicycle sometimes needs to produce energy to stay stable. Finally, the fastest are not the ones who produce the most energy but the ones who manage to use the least energy for balance and the most to move forward.

And from my point of view, the more energy you use to move forward (= the harder you push on the pedals) the more instability it creates.

In your table, for the same W/kg ratio, is it only the weight of the unicycle that influences the speed ?
It’s because I love my 6 kg 36" unicycle that I want to go uphill with it (and it’s been a long time since I ride a 29" with short cranks). And I agree with Maksym, for this race, a schlumpf is a handicap, as it is a handicap to have a unicycle of more than 7 kg, or a few kilos more anywhere.

How do you think cadence and crank length influence performance?
I think it’s harder to produce watts with small cranks and a high pedaling frequency is hard to maintain… but I wouldn’t know the limit.

On the flat, in G36, I can ride 1h around 125 rpm. I don’t have enough training on hills to know if the optimal pedaling frequency is the same as on the flat or not. For hill racing, I would be closer to this value in 29" than in 36".

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Haha, but true… the chart doesn’t account for those variables. Personally, on a sustained uphill (fitness limited), I think I prefer 115rpm with 125mm cranks, and 105rpm with 150mm cranks. (estimates…since I don’t have big enough hills around here to ride more often).
On a steep and long enough hill with the right unicycle size and 150mm cranks, the balancing energy for me is small, and I can reach at least 95% of my bicycling power. In the past, I also could do about 95% with 125mm cranks, but for sure you would hit various limits if you go super short. This is still something to consider for sure!

Also Cda, Crr, and gear efficiency (100% for ungeared, ~95% for geared).
Cda: I left the same…in reality, bigger wheel with wider tire is going to be less aerodynamic. I have no good data, but would randomly guess it could increase Cda by 0 to 10%.
Crr: Also I left the same, but a Schwalbe Big One or other high quality bike tire will be faster than a knobbier, thicker, 36er tire. Faster vs slower tires I think are up to 20% difference in Crr.

From my Schlumpf hub efficiency tests on my geared 700c, I extracted 0.48 for Cda and 0.0048 for Crr. I’d guess it’s within +/-20%…

Those estimated changes are probably sufficient to analyze this road climb, given that most of the energy is still to overcome gravity.

As you mentioned, balancing is another factor. For me, working on my riding skills likely is probably more important than the difference between 36 and 29.

I have not ridden a G36, but if that is your maximum 1-hr rpm on flat, I would expect it to be lower for a hill climb where fitness will be limited. I could be totally wrong here though. At least with my G700C and ungeared29, on flat smooth roads, I can spin much faster since they relatively slow.
A bit off topic :sweat_smile:

But, I think this highlights that a bigger gear ratio itself is not going to make most people faster. Choosing the correct wheel size is going to be important. Up Mt. Diablo in 2021, Jayden, who is only 13 years old, rode a 24". He was faster than when he rode a 29" previously.

Interesting. I would assume there is an optimal “stand up and crank super slow” cadence, assuming you have the muscular endurance to do it (maybe 60-70rpm). Then, there’s an optimal cadence for sitting, (maybe 90-120rpm). If you get stuck in between, it’s too hard to sit and pedal, but also too low of a gear to stand up. When bicycling, most people would change two gears in the rear before standing up to pedal. If you only change 1, then it can be too light of a gear to stand up effectively, and also now be too heavy to sit and spin.

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that spreadsheet seems to give times based on power (derived from rider weight and watts per kg) assuming crr and cda and total weight not much different from a bicycle.

I note that many amateurs can ride for an hour on a bike at 40kph, but the best unicyclist in the world can “only” manage 33kph. I reckon this shows that there are huge inefficiencies in unicycling (wiggle factor, need for constant pitching balance corrections), so the EFFECTIVE power from a unicyclist is quite a lot less than if they were riding a bike, so the calculations based on power derived from weight will yield incorrect (over optimistic) times? or have I missed something?

Yes, it is assuming your body can output that much power. However, I wouldn’t say they are “huge inefficiencies”. My hypothesis is that most unicyclists with the right gearing and hill can ride at basically the same power as they could on a bike.

Flat road riding
For flat road riding, 33kph is about 128rpm on a G36. I think a slightly larger wheel/gear ratio would be more optimal if it existed (otherwise people would choose G29/32 instead?), though I have zero experience, so correct me if I’m wrong. With a 65kg rider, 0.4 Cda, 0.005 Crr, and 95% hub efficiency, 240W is needed for 33.3 kph. 3.7 W/kg is already a “good” bicyclist. I think fitness is thus still a factor at 33kph, but balancing and suboptimal gearing at this high speed are also factors. I just don’t know how to quantify those. But, with climbing, fitness requirement will increase, and balance and gearing issues decrease.
Since @toutestbon has a powermeter and can ride that fast, maybe he can verify the power demands at high speed.

Also, I’m ignoring wobble, because I’d imagine it would increase “rolling resistance” a bit, but that is only a small fraction of what’s holding us back.

Uphill Road Climbing
For my Mt. Diablo climb (1000m elevation gain, 18km), my normalized power was about 95% of what I could theoretically do on a bike. My unicycling skills are also pretty poor… (can’t really idle, backwards, one foot ride, or anything like that lol).
I never felt balancing or wiggle was holding me back. I am confident even higher than 95% “human-unicycle efficiency” is possible with a combination of a better hill, gearing, and unicyclist.

The Unicon Road climb course is a perfect example (more consistent grade), and we will likely see >95% “human-unicycle efficiency” for many riders.

Thus, using a simple W/kg formula to pick a wheel size is likely a good start for most riders.

The less steep and faster, the more you have to be conservative with your W/kg capability due to the above reasons. However, I think it is still a decent starting place. If you run the numbers for a completely flat course, the chart basically just tells you to ride a G36+, or a G29 if you are “untrained” or very light (ie <50kg), which is represents what most people would ride at normal road races.

I think your assumptions are not far from the truth.
For the moment, I have the impression that 240 W can only reach 31km/h on the flat. But I train on roads that are not really flat.

The most limiting factor, whether on the flat or in a hill race, is the gear ratio.

You can find a regular climb that ideally matches your unicycle.
But finding the optimal unicycle to ride on the flat is more complicated.

I also think that a ratio between 1.7 and 1.8 (rather than 1.55) would improve the performance. But it’s very complicated to build and the closer you get to a ratio of 2, the more you have to increase the size of the epicyclic train.

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I guess the only way to find out for sure about unicyling inefficiencies would be to have a group of riders each with a good quality unicycle and a good quality “fixie” bicycle with the same gear ratio, and practice on both, and get comparison times over various courses. I would bet that the fixies would be the winners (but I would still prefer to ride a unicycle!)

edit: of course the comparison could be done against a normal racing bicycle as long as a suitable gear combination was picked, and never changed while riding, and of course the test would have to be on the flat or uphill, to stop any free-wheeling.

[yes, sorry, this is a bit “off topic” of how to have staged starts on a new long unicon uphill course, and whether there should be a transgender category and whether everyone must declare what crank length they are using and what handlebar they are using :wink: ]

If you want to go back to grenoble after the race by uni, i think a geared 29 will be the best. 15 km downhill on the road.

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