Trial unicycles?

Other than a trial unicycle being stronger what other advantages does it have over a freestyle unicycle. How does a trial unicycle improve trial riding? And whats the purpose of using knobby tires for trial riding?

well trials are all about jumping on and of things.really it has no reall advantige over a street unicycle they both excell in the type of riding that you do with them. umm the way that a trials unicycle improves trials riding is that over a normal unicycle the tire is wider.meaning you have more of a base to land on,also the weel,hubs,and crank arms are much stronger for larger drops. the purpose of knobby tires is for great grip if you have a bare tire you won’t be able to grab onto slanted surfaces. well i guess thats all about what you were asking for so hope it helped!

Not for me! lol

I ride a bald CC tire and it grips to everything, unless its really wet, but then even my two other CC tires that are new would have problem with that too. Its mainly in the rubber compound that gives a tire grip than the knobs on it.

knobs help in mud and loose soil

Jerrick is right, a slick tire with a soft rubber compound grips best to an even surface. Like knobby tires in motocross, and slicks on road racers and dragsters.The more rubber touching the surface, the better the grip.

I’m not sure if i can be bothered to rise to this, but it’s a lot more complicated than that.

Well, putting it simple when your hoping up somthing and you land on the edge, the knobbles will grip onto the edge, more grip. Not being funny but its pretty obv, try getting up stuff in trials with a slick tyre at low pressure see how far you get :stuck_out_tongue: lol And yeah the knobbles do help because as your tyre wears down on a rials tyre you feel the loss of grip.

as someone said above thats the actual opposite. The more rubber touching a [hard flat] surface, the more grip [more friction]… the nobbles just grip better on dirt and uneven surfaces cos they dig in to the dirt and around the grooves.

An opposite of this is in curling. The ice is not actually flat, its sprayed first so there are small bumps on it and there is less friction between the stones [are they called this??] and ice, so they go faster.

…and those nobs help tremendously on uneven surfaces, but hinder little on smooth slanted rock.

As an example ice is like 1000 grit sand paper and concrete is like 40 grit. The bumps on concrete, asphalt, rock, are quite large in comparison to ice, but still pretty smooth to the naked eye.

Bigger tire = more air volume = more compression which means higher ups and softer downs. For the most part…

lol
uhm
how do i put it?
if you get a sanding block, place it on a board and lift the board until it is angled enough for it to slide, and take note of the angle… then you do the same thing with half the block … with the weight of the other 1/2 included somehow … it slides at the exact same angle. it has nothing to do with friction at a basic (physics) level. but if you hit a ledge, those nobs have a high coefficient of friction against it and will actually “pinch” (i don’t know how to say what im thinking) the corner and keep the tire deflated for a longer time than a slick tire.

as far as angles go, tire flattens out, on most surfaces this helps because there are sand deposits and such. the same reason normal tires slip on the surfaces, the tire slips across the surface easier. the softer compound of the tires allows more friction and more flex so the tire “sticks” for longer.

the whole curling thing… with ice… ice melts faster in small amounts… so basically if something solid is sliding across the ice it will work much better if it can melt the ice a tiny bit as it slides.

Asside from strength the main difference is the tire, as many said. The tire’s higher volume allows you to run a lower air pressure w/o pinch flats, softer landings, and getting more spring effect to jump higher.

Doing what you said and in each case the center of mass of each block was at the same height from the board and their surfaces had the same coeficient of friction, then they would both apply the same amount of friction (because their forces are equal) , and start to slide at the same time.

However if you took two blocks of the same size, center of mass, and surface but one is heavier, the heavier block will start to slide at a steeper angle than the lighter one.

force of friction = downward force X coefficient of friction

I have been riding a bald tire like that for easily 5 months now, even at Moab it was doing fine on the trails, no slipping around for me.

I also havent felt any loss of traction/grip with it, main thing I have noticed is that my bald CC doesn’t fold as much as a new CC does, and rides a lot more smoother.

So tell me, how many bald/smooth trials tires have you been riding with, and for how long?

I was only getting at the idea of friction, nothing in depth!!

YES! Finally someone who was paying attention during high-dschool physics. Sorry I’m not picking on anyone in this thread but this issue comes up alot, and this is good explanation.

Good explanation sure, but does it really work? From my riding on a bald tire and new tire with the knobs, no. I still pinch, as skrobo puts it, just as well as the new tire does, gripping the edges of stairs, ledges, rails, and rocks.

In the last few weeks I have been trying to land on the edges of things now. Its pretty fun, specially when you just hang there for a good 10 seconds before you jump to your next object. Ive only been doing it on rails and anything 4-stairs high or lower. Don’t want to chance a bad slip, bald tire or new.

High school Pysics doesn’t work for tires

The best way to explain this odd quirk is to compare the design of train vs race car wheels. Both are designed to achieve max traction and low rolling friction.
The train wheel is designed in accord with the classic formula of psi (pressure) x contact patch in square inches x coefficient of friction (a number dependent on the material, low for Teflon, higher for steel etc) . Using this classic of high school physics, we can see why the train wheel is relatively skinny, even though they want the locomotive to be heavy. Making the wheel twice as wide reduces the psi of the contact patch by one half. So traction remains the same, while rolling friction would increase. So with steel running on steel, traction is not helped by using a bigger contact patch.
They want the race car wheel to be as light as possible. Certainly, the tires should be made skinny, small, and thus light. Yet F1 cars are famous for their wide tires. This is because of the unique properties of the rubber wheel. It makes a physical bond with whatever it touches, and this bond increases friction. So the knobby tire makes up for the loss of contact area by the fact that there is greater pressure on the smaller area of the knobs, increasing friction there. This does not compensate enough to overcome the lack of contact area.
So I believe that Jerrick’s empirical observation that he achieves better traction with a slick tire is correct. Slick tires suffer from hydro planning, and
a ball bearing like sliding on sandy surfaces. However, on clean dry surfaces a tire with maximum rubber in contact will always have better traction. That is why race cars pull into the pits to put on grooved tires only if it rains. The function of tread is to channel water and crap away from the contact patch.
On unis and dirt bikes, the knobs help grip loose soil also.

^^^^^
couldn’t have put it better, even if i tried all day
how hot the rubber is would also contribute to how much grip (the warmer the stickier=more grip)… but thats for another time, and the difference is probably negligible at the unicycling level anyway