Could somebody…
…unicycle in a loop? You know, like you can do on Tony Hawk’s Pro Skater 3.
or, like you can do in real life.
Probably not. It’d be way difficult even on a 36’er going like 30 mph. Too much weight.
No, But it would be total awesome if there was a Unicycling version of Tony hawk’s games! You could go around learning new stuff and meeting Shaun J and Joe Hodges etc.! I would buy that up in a flash (if it was on PS2)
Project Uni is getting closer and closer
THPS3 is a video game. You seem to be asking about reality. Did you know there’s a difference between video games and reality?
You could calculate the speed required to ride through a given loop, then determine if such a speed is achievable on a unicycle. It isn’t rocket science… it’s basic mechanics.
Let’s simplify the problem and see if there’s anyone brave enough to take on the problem. Assume the rider/unicycle combo weighs 75 kg. Assume the loop is a circle and that the rider can maintain your calculated speed throughout his ride within the loop.
How big a circle do we want? Well, we’ve seen riders surmount 6 ft quarter pipes. Let’s say the loop is 4m in diameter. That might be a bit small for practical purposes, but it’s a good start for now.
Let’s simplify the problem even further and give you 90% of the answer: find the centripetal force required to overcome gravity. There’s your speed.
Wow you make everything look so complicated, it is impossible to maintain a high enough speed, you will slow down as soon as you go up, and will have stopped by the time you are upside down… put it this way, it will hurt. But what a bail eh?
not true by any means, why on earth would you suddenly stop when upside down? an even easier way to work out how fast you need to go: find a video of someone looping on a skateboard, guess the height of the ramp they started on, equate gpe (mgh) to ke (0.5mv^2) and voila, speed, albeit a high estimate as it doesn’t account for fricitonal loses.
Infact:
(20h)^0.5 = v
A quick look at tony hawke’s death loop puts h at about 12 feet, or 4 metres.
Therefore v= 9 metres per second, or 20 mph. The fact that this is a high estimate, and was done in a rather large diametre loop suggest that enough speed could be attained for this feat to be possible, there are many coker riders who can hold 20mph reliably.
So who’s it going to be?
This equation is useful if you’re dropping the rider from the top of the loop… for the purposes of this “idea”, however, it is misapplied.
We’d hope the rider would not drop like a rock once he reaches the top of the loop. Here, we’ll need to equate Fcentripetal and Fgravity (as I suggested above), getting the result v = (gr)^(1/2) where r is the radius of the loop.
The speed derived from this equation is the speed the rider will need to sustain at the top of the loop… getting to the top of the loop, however, requires a much greater speed.
Here is where we bring energies into play. We need to find out what v at the bottom of the loop gets us the required v at the top of the loop.
(1/2)m(Vbottom)^2 = mg(2r)+(1/2)m(Vtop)^2
(boring math)
Vbottom = (5gr)^(1/2)
For our 4m high loop, this gives us a Vbottom of about 35.7 km/h, or 22 mph. Keep in mind, due to friction and wind resistance, the actual speed required will be a bit higher.
Vtop, however, is a mere 15.9km/h or 9.9 mph.
I was merely calculating the speed that the skateboarders are attaining when they enter the loop, and succeffully get round the loop in videos I have seen, this is a calculation based on empirical evidence rather than any kind of theory. The height i used referrred to the entrance ramp they used to get up to speed, not that of the loop. Obviously my calculation would only be valid for a loop of equal diameter to the one in the video i observed.
The fact that a unicyclist could hopefully propel himself round the loop, while a skateboarder just coasts through the loop, means that the entry speed could be lower.
‘need 8.65mph’ but he could run at 17+mph, and seemed to just be able to complete the loop.
For someone with no experience with stunts, it must be difficult. But, how hard would it be for a unicyclist with the skills and experience to do this??
Like Master Maestro said, weight is irrelevent, speed is.
I have no expertise on the math side, but I can imagine it will be harder than what’s shown in the video because a unicyclist is elevated from the riding surface, which means he’s farther away from the loop. The loop needs to be bigger and the unicycle needs to keep you as low to the ground as possible. A geared 24" or 26", perhaps?
Also by watching the Pepsi video, it looks like the most challenging part (physically, not mentally) will be riding out of the loop. You not only have to maintain your minimum speed through the top of the loop, then you must accelerate hard to get the wheel back underneath you.
I think it’s doable. The person who does it will have to do a lot of building (making a solid loop, bigger than the one in the Pepsi video), and be pretty fearless!
Oh, I’ll also add the option for a non-circular loop. If you look at roller coasters, nearly all of them loop in the shape of an ellipse. I believe this lowers the required entry speed, which also lowers the g-forces created. I’m not sure if the same principle applies to a self-powered vehicle, or if you’d need even more acceleration to ride out the bottom part. The only circular roller coaster loop I know of is the American Revolution coaster at Six Flags Magic Mountain in Southern CA. It was the first looping coaster of the “modern” era; 1976 I think. All the others I’ve seen are elliptical.