Here’s a question about tyres for muni I haven’t really seen discussed in general. Now that many tyre manufacturers make specific front and rear with different tread patterns and rubber compounds, does anyone know if front or rear are better for unicycles? Or is it still just trial and error with each model?
I always thought the uni wheel compared to the bike’s back wheel as that gets the most power. The front wheel is basically pushed by the backwheel.
I tend to go for “front” tires. They are typically designed for more grip in cornering, while rear tires are either designed to be faster rolling, or for forward/backward traction. Since unicycles have all the weight on one tire, forward/backward traction is rarely an issue in my experience.
I’d also consider front tires more universal (e.g. Magic mary front and rear is quite common, while Big betty on the front is rare).
Rear wheel just follows the front wheel, the front does 100% of the steering and 70% of the braking. I think that on a unicycle the tire has to pivot and steer is a more important part than receiving forward torque.
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I’m a fan of having better grip while accelerating.
My braking is more of a drag so the tread torque is spread around the whole tire while checking speed.
While climbing though, the torque surges twice every revolution so I want the best bite during this.
All this to say that I’ll put the tread to “catch” more under acceleration.
Any vee shapes in the tread will always point forward when in contact with the ground. (trapezoid grips will have the short side facing forward)
I’ve always seen bikes with the opposite configuration as (I’m guessing) they want optimal braking characteristics for their gravity assisted sport.
This is just what works for me.
That’s not quite how it works. It’s not so much about traction as clearing mud, as it squeezes into the v shape it pushes other mud out the wider side. That’s why tractors and dump trucks have the chevron tread with the v pointing backwards at the bottom too. Actual traction comes from the shape of the blocks and the spacing between them, along with the rubber compounds used. Usually the blocks themselves have a ramped edge at the front for rolling speed and a square edge at the back for traction under power. But that’s for bicycles so the forces and handling characteristics are different to what we need.
so you’re saying the opposite of what Finnspin is saying?
The rear wheel of a bike is for traction and pushing the steering wheel forward, like with a car? Sure enough the rear wheel follows the front wheel, but the steering on a uni just depends on how much you lean to one side, whatever the profile of the tire.
That‘s true for long curves, but for sharp corners the grip of the tire makes the difference between making the turn and having the uni slip away under your butt. I‘m in the front tire camp, except maybe for hill climbing on unpaved terrain.
Interesting question for which I unfortunately have no test/trial data but only theory.[quote=“finnspin, post:23, topic:290199”]
I tend to go for “front” tires. They are typically designed for more grip in cornering, while rear tires are either designed to be faster rolling, or for forward/backward traction. Since unicycles have all the weight on one tire, forward/backward traction is rarely an issue in my experience.
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I can follow but my (not backed by data) theory is different: I disagree that forward/backward traction is not important and would consider it about my number one factor (sure, tire should steer where I want, provide flat protection roll well, and not be pressure sensitive) but concerning traction, I don’t find myself washing out in corners (like on a bike) but I do want the most braking control on steep rooty/rocky wet terrain.
Thus, I have almost always used rear tires and directional tires like the DRH II tend to be my favorites. My thinking is:
- front tires are optimized for cornering, especially at high angles even when the tire may not be weighted. In muni I rarely have the high angles as in biking and the tire is almost always weighted (many front tires have big knobbs only on the sides)
- rear tires are optimized for max traction both accelerating and braking (as the rear bike tire is the most likely to skid for lack of grip) and not concerned with high angles.
For the full consideration there are actually multiple options:
- non-directional (symmetric) front or front/rear (symmetric rear is rare)
- front directional
- rear directional
- and some people seem to choose rear directional in the opposite direction
As I said, I have no test experience and have used mostly rear directional tires and a few front symmetric. For more lightweight tires for XC I have been happy with nondirectional although with the main weakness being DH traction/braking conditions (but mostly due to compromise for less weight and thinner sidewalls compared to beefier tire).
Does anyone have any direct comparison data? Say a DHR vs DFR of the same tire/compound.
I tend to mount the tires backwards sometimes if they feel a bit awkward in the official direction. This can change the handling and cornering behavior quite a bit, especially if the tire has an arrow (inverted V) profile. So, in the official direction (arrow points forward when looking down from the saddle), it may not be possible to steer the unicycle precisely, almost oversteering, but if you turn it 180 degrees, the V has a steering-stabilizing effect. The unicycle can, under certain circumstances, track straighter and be steered with more control. The rolling resistance will then be higher, but the uphill grip will be better.
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So do I. Two tires were better in the correct rotational direction, one was better the wrong way around. “Better” in this context means less auto steer, though, not better grip. Actually, I didn’t trust the one tire that I rode “backwards” 100% for sharp turns.