Hi, like I said, I’m 5’2 and I have been riding for about 5 months now. I have a torker dx 20" and I am currently putting together a trials set up with an older summit frame. I used to train and compete in sprint triathlon and I loved my road bike. It had 650c wheels. I want to get back to riding distance but since I became madly addicted to the unicycle, I can hardly get myself to ride my bike. So I decided that I will build a distance unicycle. I plan on having my wheel built at my local bike shop, and I am going to build my own frame. I have a few questions for you distance riders:
What size wheel should I get (remember I am 5’2, 27" inseem)?
What size cranks ( I will ride flat, moderate hills, no mountains,
I am also a powerful guy, I love uphills)?
I would like to make it light
I do not weigh very much (125lbs)
where can I get bearing holders?
I would like something simple
I know the coker wheel is 36, half of that is 18, plus 5 for cranks is 23, plus 2 for seat is 25, that only leaves me 2 inchees for crown and seat post.
What if I use a coker wheel and instead of having a seat post, I custom build the frame for my height and bolt the seat right to the top of the crown?
Randy, I am 5’4"(ish) with a 28"(ish) inseam. ish=slightly more by a fraction but not much. I used to ride a standard, unenhanced Coker with no problem. I can’t remember if I had the seat post at its lowest point, but here is what my set up looked like.
Unlike you I am not a physically powerful guy. I converted to a 29" uni and am happy with the decision. Given that you’re fitter than I a Coker may not present the challenges it did for me. I was never able to idle, mount confidently in confined areas, or feel control riding in unpredictable automobile traffic. I do these easily on a 29"er.
The UK branch of unicycle.com sells a custom short person’s Coker frame. The seat mounts directly on the crown. The two legs of the frame can extend so you can adjust the height. Roger from the UK branch of unicycle.com could tell you more about what the minimum leg length is for the short person’s Coker. If necessary you can order from unicycle.com UK if you want that frame.
You should take a measurement of your current unicycle to see what your seat height is. Measure from the pedal in the lowest position up to the top of the seat. That’s the important measurement for determining if you’ll be able to reach the pedals on a Coker sized uni.
There’s also the Schlumpf geared unicycle. A geared up 29er will give you a 43.5" effective wheel size on a 29er sized uni. Just make sure you’re sitting down when you find out the price.
I’m 5’9" but have a 30" inseam. I have both (Coker and 28). It’s really a matter of personal preference. I’ve decided to eep the Coker and sell the 28’r.
The bearing holders can be bought from unicycle.com. Here’s a link to the Coker frame I built:
For bearing holders you can use the standard Taiwanese main cap bearing holders from Unicycle.com. They’re stamped metal. You’d need two sets so for $16 you’ve got your bearing holders.
The Taiwanese things work, but they’re not exactly precision. They do allow some bearing movement (sliding and rocking) and they don’t put even pressure all the way around the bearing (there’s going to be distinct contact points with the bearing instead of smoother and larger contact patches). If you’re building up a high end custom uni and using a high quality wheel (like the U-Turn strongest Coker wheel in the world) and a high quality frame, you can notice the difference.
One solution is to machine the bearing holders from a shaft collar. It requires some machining. It makes for a better bearing holder. Here’s some threads that cover that approach: thread one thread two thread three
And check out Steve Howard’s gallery where he machines a bearing holder from a shaft collar.
The shaft collar solution isn’t always perfect. Some shaft collars countersink the bolt head too far and leave the metal too thin under the bolt head. Jagur mentions that problem in thread one. But not all shaft collars have that problem. I have a GB4 Coker frame that uses machined shaft collars for the bearing holders and I think they’re fine and strong enough.
Another problem with the steel shaft collars is that they’re heavier than they need to be. There’s a lot of material in them and it’s solid. Custom made bearing holders can be made thinner and with less material.
For the custom route you can make your own bearing holders by welding on tabs to a machined out bit of tubing or other material. I’ll attach a photo of a bearing holder on my DM Advanced Ringmaster to give you an idea. Other frames, like last year’s KH frames and the Hunter frames, also use a similar custom bearing holder. My DM has lips on both sides of the bearing. The KH frames only had a lip on the outside side of the bearing.
You’re going to want the crown as narrow as possible. You should also go for a rounded crown (the stock Coker frame has a rounded crown) rather than a squared or flat crown. With the seat being so close to the crown your thighs are going to rub on the unicycle frame and rubbing against a smooth rounded crown is a lot more comfortable than rubbing against an angular edge on a flat crown.
To make it narrow you could do a design similar to the Hunter frames using two small diameter bicycle tubes per leg.
Personally, I’d go for the 29er. At your dimensions there is no room under the saddle for anything at all on a Coker (such as a handle). And I do think you will find it difficult to mount even under ideal conditions. There are exceptions, of course, such as Nathan’s son. However, if you want a much better chance at enjoying your ride and putting in some productive miles this summer, my recommendation is the 29er. You can always add a Coker later. The 29er parts are much cheaper, there is a huge selection, and a Sem XL 28" wide frame makes a great fall-back or even temp frame while you build your own.
My son is now 5’2" and rides a Coker very well. He can use up to 152mm cranks for Muni but generally uses 125mm for on-road. He did his first Coker ride 13 months ago and I think he was 4’10" tall then. Back then he could only use 125mm cranks. Photos of his first ride. Now he rides a Hunter36 and you can get Rick to make you one with a short seat tube if your legs aren’t as long.
29ers are great and certainly have their place (cross country muni or racing where it’s just too technical on a 36" wheel). But Cokers are really a whole different experience. If I had to limit myself to just one unicycle, much as I love Muni, it would probably be my Hunter36.
Brad’s almost ready to turn 12 and like Beau, he’s grown quite a bit and in nowadays at 5’- 2½". U-turn had a good comment though about the seat height and no room for accessories. Something to think about.
Bruce, nice videos. Watching 4’9" Brad mount the Coker reminds me of Beau back then. He sure looks confident and has no trouble riding. When Beau was 4’11" or a little less, he rode a Coker 85 miles in 2 days including a couple thousand feet of climbing. Amazing what kids can do.
Beau just turned 13 this month. Yes you met him in Seattle at Unicon. He’s looking forward to our Swiss tour this summer. If you’re interested take a look at the web site Andy setup: Alps Unicycle Tour 2005. on the Riders page you can read about Beau’s motivations for doing long distance riding. On the Route page, you can see detailed info on how much distance, climb and descent is planned. Some of those days are huge.
Unicycle touring (which could be just a weekend or even a day) but can be weeks or months if you have the time is awesome. But I can’t imagine doing it on something with a wheel smaller than 36". In fact we’re going the other way - gearing up to get higher speeds by bigger effective wheel sizes. Basically, you would really be bummed on one of these tours on a 29er. Go with the Coker!
Heh, well I took a beating on that one! In truth, though, not everyone adjusts to a Coker as well as a 29er. The truly best thing to do is not to buy either, but get to some meetings and try people’s unis out. Take a few test rides, borrow a uni for a few days, that kind of thing.
The other thing to think about is not to try to get or build the ultimate distance uni in one go. Most distance riders at this stage go through many iterations of their equipment. As you ride, you will develop ideas that you never would have thought of otherwise. If you look at older tours you will see folks on a wide variety of equipment. What made them distance riders was simply: doing long rides. You can do that on a $200 uni or even less of any size. Then you are already developing into a distance rider, and everything after that is just refinement, improvement.
Hah, ‘many iterations of their equipment’ is an understatement in my case anyway! The most important thing is to get out there and have a good time riding. The exact equipment doesn’t matter so much as long as it fits your body.
the 36’er is looking and sounding really good to me, I have just a few more questions:
Is the stock coker rim to weak for someone my size? or will it hold up to my height/weight? I have read that it is not to good
If the airfoil rim is a better choice, where can I get one? I think uni.com is out of stock
I want to go some-what cheap, would you recomend something like the uni.com wide hub, airfoil rim, custom short frame (I will build)? or is there something I should do that will make my first coker much better?
With like 125mm cranks, can you climb hills? what is an approximate avg speed I could expect if I am a decent bike rider?