narrow hub racing coker

Remember that flange width is actually flange diameter, and flange spacing is the distance between the flanges. unisk8r was using them distinctly, but I think the following discussion didn’t really. Unicycle flanges tend to be all the same diameter, which is huge compared to many bicycle flanges. Unicycle flanges correctly tend to be larger, like track bike flanges, because a unicycle generates a lot more axial torque than the typical road bike with gears and rim brakes.

Flange diameter is a only minor player in the wheel stiffness/strength geometry of flange spacing and ERD.

Flange spacing is roughly equivalent to hub width.

Yes I know that, but there are hubs which have the flanges very close to the bearings. I know this because I had to make sure there was enough clearance for the Ti frame I’m getting from Triton. There is not much room for error.

So in terms of this thread, it sounds like “narrow” means a standard small-wheel unicycle hub. That’s what my Coker has (that’s what they all had for the first few years). I’ve ridden it thousands of miles, and on plenty of dirt though not in an abusive way. No problems. As long as you don’t beat it up with side forces you should be in pretty good shape to just use a “regular” unicycle axle.

And I’m glad to not feel the need for a splined axle & cranks. I’m not aware of any splined system (for unicycles) that’s built with speed and lightness in mind. In fact, the only problem I’ve had with my Coker’s hub (not to mention the cottered hub on my 45" big wheel from 1982) is the worry of wear & tear if I change the cranks a lot. What, are people breaking axles and/or cranks on their Cokers?

There is no reason why we can’t have a lightweight splined hub except that the powers that be only seem interested in catering for the Trials and Freestyle market. Most of the top lightweight bike cranks and bottom brackets are splined.

Ken, if I came across as insulting, I’m sorry; that was not my intention. It just seemed that the terms were being confused throughout the thread.

One reason for’s term “wide hub” is that the standard old-style Coker Big One hub is narrower (flange-to-flange) than both the Suzue unicycle hub and the hub. This is one reason that wheel is so weak.

If you are properly cleaning and lubing the tapers and threads when you change cranks, and using a torque wrench, there should be very little wear and tear when changing cranks.

It’s ok Dave, I wasn’t offended. I think we both know what we’re meaning when talking about flange widths. As you know I’m not a big fan of the superwide hubs but we’ve gone through this before on many other threads.

The current ‘wide’ hub is a pretty standard size in terms of bearing spacing, regardless of the flange width. Not many frames need to be bent in order clip onto the bearings. It’s only the ‘superwide’ hubs that need special frames to accomodate the wider hubs. So that’s why I think they should end the confusion and just call the ‘wide’ hub a std hub because you can use a pretty standard frame with it.


How vas it to “Crank” up in the alps on a narrow hub?

I only got 2 Coker’s, both with wide hub. One width 135mm and another with 125mm bearing to bearing width. I do a lot of “Crank”-ing here in Norway in the mountains. One of my friends have a unicycle width narrow hub. I think it is a 100mm bearing to bearing width hub. He manages to go some quicker easier than me (on tarmac, flat and 125mm cranks). But when going uphill he seems to lose the speed very fast, compared to me with the wider hub and the same crank length 125mm. He must also tension the spokes very often. I have never tensioned a spoke on my wheels. And have done nearly 10.000km on gravel rods with a lot of cranking.

I maybe build a wheel with narrow hub just to use at flat tarmac. When I do Coker Muni and use 150mm cranks and do climbs 10-15% the wheel do a lot of flex. I don’t think a narrow hub can tackle that. My weight is 82kg.

I don’t think you can compare your speed and climbing ability with your friend. Maybe you’re just a better climber than him!

I had no trouble with the Std UDC hub on the Alps Unitour. It climbed and descended pretty well. I’ve probably had the wheel trued twice since I had it built 4yrs ago. I weight 58kg.

had it trued? at a LBS or a uni expert?

LBS. Best wheelbuilder in town

Did he use some sort of custom stand or just by eyeball

Go Local Bike Shops!

I always get my wheels built by my favourite shop. They give me amazing deals, and do a better job than I have seen anywhere else.

For my coker wheel they even had to built up a special setup to true it, and they charged me 25 bucks still!

do you know what/how they built up a truing stand for a 36er?

What modifications must you make to fit a ISIS hub on a Nimbus 36" frame? Or Is it other frames better suitable to fit the ISIS bearing size and spacing?

First thing you do is check which bearing houseing you have fitted to the Nimbus, there have been one batch that had the larger bearing housing fitted on the top cup. If this is the case then all you need is 2 new lower cups. If you unlucky and have the 40mm cups on top and bottom then you can not fit the 42mm bearings in them.


Here is my simple 36" wheel modification to an otherwise stock Park TS-2 bicycle wheel truing stand. I made the 7" steel extensions which are attached to the arms with 2 bolts, and a pin which rests in the stock axle groove.