What's the fastest configuration for a 36?

I would like to upgrade my 36 for speed, but not sure whether I should go for a geared hub or small shanks. My schoolboy maths tells me that the gearing should be the same between these two configurations on a 36

 150mm shanks with 1.5 geared hub
 100mm shanks with standard fixed hub.

However, I can imagine that there will be other effects that will affect the control and speed. I would love to hear the pros and cons of geared hub versus short shanks from some speedsters out there.

100/102mm cranks are cheap! Start with those and see if they work for the places you ride. Long as it’s flat enough, you’ll have the budget solution! Also the option to go a little longer if those are too short.

The “best” configuration for speed depends on a number of factors, involving your chosen terrain, and your own preferences in riding. For the Schlumpf, you have to want to challenge yourself to new learning. That is, perhaps, my favorite thing about it. It takes new skills to cruise in high gear, and to make the gear changes. I’m still learning.

I’d go with a rosemary braise on the shanks, with a little bit of garlic and red wine. It’ll go fast!

So, everything I’m about to say is based on my experience, so your mileage may vary, but I think (hope!) it’s pretty reasonable:

Though it’s possible to go pretty durned fast on 100mm cranks at 1:1, I am pretty sure the general consensus here (and my opinion, too) is that the 150mm cranks at the 1.5 ratio are hands down going to be faster in just about every situation, assuming that you can get used to them. (And not to worry, if you have them, you most definitely will get used to them!)

Of course it’s the same “total gear ratio” or whatever term was used long ago to describe the mechanical (dis)advantage your foot has over the ground, but the 150mm cranks at 1.54 gear ratio are going to use a whole lot more of your leg’s range of motion with a whole lot less mad-spinning cadence. (There’s a reason road bike cranks usually range between 170 and 175mm!) If your experience will be at all like mine was, your pedal stroke will be smoother, your force on the pedal will be more even, and your legs will generally love you on the 150 cranks compared to spinning the 100s.

In some cases, on really steep grades (whose steepnesses depend on rider comfort I suppose), the 100mm cranks in 1:1 can be faster than the 150mm at 1.5:1 simply because keeping balance is easier when torquing the pedals hard up a hill if you’re not having to use the uni frame and your body as a torque arm for the geared-up hub (having to pull the seat back between your legs when pushing the pedal down!). It can be easier to mash 100mm cranks up a hill than to mash 150mm cranks while geared up, just because of the way balancing works in high gear. But if a hill ever, ever, ever gets steep enough for this to be the case, you long-ago would’ve shifted the 150mm geared setup back down to 1:1, and begun to use the 150mm cranks at 1:1 in “ungeared mode,” which has a huge advantage over climbing such steep grades with the 100mm cranks alone. I think that’s why John mentioned that the 100 cranks would be awesome if it’s “flat enough:” because you’re basically locked in “high gear,” with “high gear” meaning teensy crank arms.

So, basically, yeah, the geared 150mm setup is the way to go if you want to get around as fast as you can, but it’s really expensive.

I’ve seen some people do things on ungeared 36ers, too, that are just nuts to me: for example, in July’s races here in Northern California, Scott and Martin finished only a couple of minutes behind Corbin on his geared 36. So ungeared 36ers can seriously haul with the right riders.

I would say that if you’re on a budget, the 100/102 cranks like John Foss is recommending are a no-brainer, as the extra MPH wouldn’t be worth the extra $1500 or whatever a hub costs these days (over a conventional hub).

If your budget can include a hub, then I soundly believe you won’t regret getting one. Ride it and you’ll be hooked! It’s seriously like having two 36ers in one, with one of them being so fast that no other unicycle (except mayyybe a geared 29) can touch it!

One other thing to consider is what is currently limiting your speed (on your existing setup).

Personally, my top speed on my 36er seems to be a psychological limit. I usually use 145mm cranks, and average about 13mph on a ride, with a max of around 16 or 17mph. I can physically spin that length of cranks faster, because I’m about the same speed on a 29er with similar cranks, so it must be a perception of danger/lack of control that’s stopping me going any faster.

I have a pair of 125s that I occasionally put on the 36er, which actually slow down my overall journey times because of the loss of control. Short cranks are definitely not for me (although of course plenty of people swear by them).

As for the Schlumpf, I’ve only ridden them a couple of times, so I can’t really comment apart from saying that it’s a good feeling not having to spin like a maniac to go at a reasonable speed. A lot of money for a bit less leg-twiddling though… and presumably my cowardice-governed 17mph top speed would still stand :o


Ahh, I have a feeling you already know the answer.

geared is going to be expensive but a better setup.

. . . but I am seriously considering getting a pair of 100s or even putting my 90s on for riding the silver comet trail here near Atlanta. It’s about 80 miles for a day trip out and back to a little restaurant I like to go to. All of it is ridiculously flat. . . That’s the only time I would try it though. I like my 150s for around campus : ) ultimate control, which lets me play around a bit offroad if I want, or generally show off with one foot riding or idling without much trouble. : P

Same here. I have a geared 36" and a geared 29". Top speeds are the same. It is definitely a psychological limit.

About the original question: It depends on the rider. Personally, I can’t and I don’t like to spin very fast. The geared hub allows me to reach speeds I would never be able to ride on an ungeared uni. The lack of control on big wheels with short cranks scares me -and slows me down. But as it was already said, there are other people who love short cranks and can go really fast with them.

After all, you will have to find out yourself.

How fast do you imagine going? How often do you want to ride fast? Do you want to use your Coker for other things as well, like MUni?

I have some 125’s that I occasionally use on my 36, but I have decided that I don’t really care for them. I have settled on 140’s as the ideal length on that uni. It gives me better spinning than I get from 150’s, but it gives me the control that I need to be comfortable moving along at a good clip. My average speed with this setup is around 12mph, and I have gone faster but not without a little fear.

Haha :slight_smile: Fear comes above 14 mph, but you get used to it… :wink: If you are a coward like me, you’ll buy all kinds of protective gear and wear it while going fast.

The question is: How fast can you run without falling, in case of an UPD?

Put Chuck or Corbin in the seat. Done.

Speed and Fear

I agree with Rob that some of the problem is psychological. I usually run 125 MM cranks on my 36" and typical speeds are probably 12-14 MPH. The average speed is a bit lower due to hills and stop lights. The maximum speed is around 17.5-18.1 mph on a smooth downhill near my home (as measured by my cycling computer.) It is hard for me to imagine going much faster with an ungeared Uni because my cadence is already pushing 180 rpm and my control is shaky.

I have not tried a geared hub, but it would get me away from the cadence limit, and probably bring me into the raw fear limit. I am sure I could go faster, but I do not know that I would or even that I really want to hit high speeds. This concern is one reason I do not have a Schlumpf Hub already. Last weekend I UPDed going about 12 mph and ended up with blood dripping from various appendages. I really do not want to loose it at 20 mph on a unicycle. I expect I would have better control at 18 mph with a Schlumpf hub, but I am not sure I want to go there.

Let us know what setup you decide to get.

Thank you everyone for this invaluable information. That’s just what I needed to know.

I have the budget, so it looks like I will be getting a Schlumpf hub. Now, it’s just a question of how long it will take me to learn how to ride it.

Thanks again,

Interesting how people speak of “fear” or “psychological limitations” as the limiting factor for higher speed. One could also describe the same mindset as based on “experience” or “good judgment”.

Good judgment comes from experience and experience comes from bad judgment.

OK, my top speed is limited by my poor judgement and lack of experience :p. Either way, the point I intended to make is a higher gear doesn’t necessarily mean higher speed (although it may make a given speed more sustainable for longer).


Some of us don’t want to experience the consequences of that bad judgement :stuck_out_tongue:

Pranged in a bike race years ago, broken collarbone and shoulder blade…


No. It is good judgement that tells you not to go faster due to lack of experience.

In case of poor judgement, you would go faster than your experience allows…