Coker crank size for hills

I’m really interested in getting a Coker but its fairly hilly riding around where I am. I’m going to get one regardless but I was wondering what crank size to use. I have a 29” uni and do fine with 125s. Could I do the same with the Coker or would 150s be needed for the hills? I have never ridden a Coker but I’m an experienced rider so that’s not my concern. I just want to be able to pull the hills when touring. Thanks for any advise.

Even 150s may seem pretty short to you at first. This depends on how hilly your hills actually are, and your personal preference. Also on how quickly you adapt yourself to the Coker.

I use 125s for my commute, which is pretty flat. For the small hills I have, if they were a little steeper I might be inclined to use my brake, but I hardly ever do. Without a brake, you’ll need cranking power to stay in control on the downhills as well.

Thanks for the input. I plan on getting a brake for sure. I’m looking at a GB4 frame with Airfoil rim/UDC hub wheelset. I’ll start with 150mm cranks and see how it goes.

The GB4 looks like a quality frame. Most of the pics that I see of Cokers use the stock frame but I wanted brake mounts out of the box. Any comments on the GB4 vs stock frame?

I had a 29 with 125s then got a Coker with 150s, if anything I found the Coker slightly easier due to the increased momentum in the wheel. If I hit a short hill quickly enough I only really need to work towards the top, whereas on the 29 I’d be working almost all the way up.

If you work out the ratio of crank length to wheel radius for a 29 with 125s and a Coker with 150s the numbers are very close, 2.98 and 2.93 respectively, so a Coker with 150s should feel relatively familiar if a little heavier.

I’ve just switched to 125s on the Coker and it’s definitely harder work on the hills, but I think I’ll get used to that in time.

Good luck with the new Uni


Re: Coker crank size for hills

On Mon, 2 May 2005 09:44:32 -0500, “paul royle” wrote:

>If you work out the ratio of crank length to wheel radius for a 29 with
>125s and a Coker with 150s the numbers are very close, 2.98 and 2.93
>respectively, so a Coker with 150s should feel relatively familiar if a
>little heavier.

You probably mean the other way around: ratio of wheel radius to crank
length. The again, by my calculation, the numbers are 2.95 and 3.05
respectively. Still quite close though.

However, as to feeling familiar, there is of course more to how you
‘feel’ a unicycle than just the wheel-radius-to-crank-length ratio.

Klaas Bil - Newsgroup Addict

“When it comes to the family jewels, you won’t be having fun until they’re having fun. - Jake D”

It’s largely personal preference.
I personally find that there are few hills that my 140’s can’t conquor. I know people that do fine on hills with 125s, while others use 170’s for everything.

Your coker will probably come with 150s. My advice is to try those, and adjust as you feel necessary.

My Qu-ax 36" unicycle (Coker? See this thread ) came with 150s on it which I tried but they were too long for me so I quickly changed them to 125s. I’m happy with the 125s for now but I’ll probably go shorter when I’m more used to it. The only time when longer cranks would be of benefit for me would be downhill but I’m getting a brake for that.

I think leg length has a significant role to play in crank length preference but I’m not sure why, it’s just a hunch. BTW I have fairly short legs and use 125s for Muni also.

A little bit off-topic, but on a bike people with short legs often prefer to use shorter cranks, in proportion to the length of their legs. Mass-prduced bikes (even a lot of children’s bikes) almost always come with 170 or 175mm cranks, which are far too long to be comfortable for shorter people. But on a bike you can compensate for the lack of torque of the shorter cranks by gearing lower and pedalling faster. On a unicycle shorter cranks means you need stronger legs - but saying that, shorter cyclists do tend to be good climbers.

I mostly ride a 26x3 with 165s, and I can’t imagine using anything much shorter even with that wheel size - up hill is fine unless it gets really steep, but going down some even fairly steep hills (nothing extreme, just 1:6 or so roads) I’m struggling to hold it back. I would say I have fairly strong legs, but then I’ve been a cyclist all my life and only took up unicycling just over a year ago, so perhaps I just haven’t developed the “backwards pedalling” muscles enough. I’m tempted to have a go with a coker, but I think I’d need brakes for the descents!


The answer to this question depends a lot on how much riding you’re going to do and how fast you want to go on the flat.

If you ride a lot you’ll get stronger legs and be able to ride with shorter cranks. If you want to ride really fast on the flat you have to ride a lot and short cranks will really help your speed.

I’ve got 110 cranks on the coker. Without brakes you can ride down 1 in 7 hills but it’s hard work once it’s that steep. If you’ve not got a brake downhill is the big thing that is hard. I ride a lot though (10 miles most weekdays plus long rides at weekends), so I can ride more than most people.

It also depends a bit on how hilly you mean by hilly, if you mean 10,000 feet mountains and massive ascents then you might want really long cranks, you might even want 170s or something. If you mean rolling hills and nothing about 1000 feet, you could probably learn to use shorter cranks just fine.

Whatever happens, riding with 150 cranks is probably a good start, then moving down after you’ve ridden a few hundred miles if you feel you’re needing a bit more speed.


Thanks again guys for all your comments. I have nothing extreme here as far as hills go (2000-3000ft peak elevations) and roads can have climbs of 1000ft or so over a few miles distance. I plan to stay mostly away from crossing over the mountians sticking to the rolling hills in the lower areas. There you may run into some short but steep hills. I have ridden a 29" uni w/ 125s on all of these roads no problem without a brake. I have very strong legs and have good endurance I’ve just never experienced a Coker before. I’ll start out with 150mm cranks to get used to the uni then tweak it as needed. I’ll see how it goes without a brake at first. I’ve been riding so long without brakes and like going down hills as it works your legs the opposite way.

I just know that riding the Coker is going to be the coolest thing since learning to ride. Can’t wait!!!

Looks like is out of stock of the Airfoil rim version. Any other source for these?