Calling all Coker Muni riders...

All the comments from the Southern California MUni group support the use of the Duro’s rounder profile vs. the Gazz.

On bikes the situation is totally different, and can’t be applied to unicycles. On bicycles the turning radius is supplied by the angle between the two wheels, whereas on unicycles the turning radius is formed by the interaction of the tread with the ground.

Extending the knobs further up the sidewall would take care of any traction issues on higher-speed cornering off-road, in my opinion.

One issue that would become prominent is frame clearance in the presence of more prominent knobs (of whatever cross-section). It might pay to have an off-road tire with slightly less volume, so that the overall cross-section has the same dimensions as the current tire. This would allow compatibility with all the existing frames.

These are exactly the conditions where the TA is not a good off-road tire. Imagine riding a slick on your bike in a typical North Island rainstorm! I’ve seen a guy tumble on wet grass with the TA when he probably wouldn’t have with a non-slick.

I would take volume over knobs any day for off road control

the coker tire, as is, is great in anything but slick mud, a little grippier of a tread would make it perfect.

i bet a 2.3" tire would rock!

Last year this happened to me… After riding in gravelly mud with no issues earlier in the day, I went on a riverside path. Successfully spun out a steep muddy slope that my riding buddy on a 26" muni didn’t manage. Awesome. I continued down the wet singletrack going at a reasonable clip due to the speed gained on the slope. Next thing I knew my TA stepped suddenly out to my left, I sprawled off my uni to my right (as luck would have it, into a patch of stinging nettles) and landed twisting my ankle underneath me hard. It took weeks for the sprain to go down, and I felt quite lucky I didn’t break it… I still fancy I can feel a lump there.

Now, really this was my own fault for doing something dangerous so I’m not complaining. The TA handles fine on dry singletrack etc but after that experience I went back to using my 29er / Kenda Klaw muni for anything muddy. I’d be rather interested in a muni-capable tyre with knobbles so that I could ride not-too-technical offroad in the wet without the likelihood of a repeat performance being quite so high.

Hmm…but how would that make any difference? You’re still going to lean the tyre into the turn and the force will still be directed towards the apex of the turn.

Round tyres feel sketchy on the loose stuff

Well, there are a couple of different mechanisms involved in a unicycle turn. The first is the planetary-orbit kind of thing; you’re falling towards the center of the turn, and the turn (initiated by the countersteer) keeps you in orbit until you exit. The second is the rolling-cone effect, where a cone-shaped object will turn if it rolls on a surface. This effect works on unicycle tires of the appropriate cross-section (under load, of course), and helps turn the tire itself and keep it from “scrubbing” along like a car without a differential. This effect is negated in tires with square cross-section when you ride up on the edge knobs. Moreover, being up on the knobs is a more squirrelly, less stable tire surface.

Tires that turn the best for unicycling have both mechanisms working for them. The second mechanism is why, on hard surfaces, the Big Apple turns sooooo smoothly and the Gazz does not.

The first mechanism is also in effect in bicycles. The second effect is not, or is very minor, since both wheels, far apart, are creating the radius of the turn, not the tire itself.

Ken, I realize that some of these things are highly personal, and respect that. I just know that for me, the Gazz is not an easy turner, and I’ve heard others say the same.

Perhaps the best off-road tire for unicycling would have a less-pronounced edge than the Gazz, but still retain a rounded version of it.

There are other issues besides cross-sectional profile. Lots of the 29er tires are so light, that despite having a nominally round cross-section, when they are loaded down by a unicyclist they deform so much that they are quite unstable (cones with unreliable dimensions). This results in the cyclist adding way more air than there should be in an off-road tire, just to maintain a loaded cross-section with some predictability. So there is an interaction between cross-sectional profile and sidewall stiffness that is important to unicyclists, much less important to bicyclists.

I wil have a extremely light Coker tire for use on gravel. The old Coker tire is fine. But I look forward to a lighter tire. Softer rubber, more volume and a lot lighter. The knob patterns don’t botter me. I ride only in fine weather. The pedals also get slippery in rainy weather. What about a 700-800 g Coker flyweight tire!!! I will buy that.

I also should have a Coker spike tire. But that is another question.

And what about the tube. I have 29" tube in all my coker wheels now. What about a 36" light tube in latex?

weird thing is, I understood that. any tire designed for unicycles should be round, like you said.

I ride my Coker in the trails a lot, and most of the time, the lack of treads is of no concern to my riding abilities. However, a little bit of tread would help in the muddy trails, and the winter trails that I ride. I would buy a treaded Coker tire for sure if it were make available.

In my opinion, a small tread would be good, too much tread would likely make it too sluggish.

Ride on, Tim.