Coaster Skiing

This came across my Facebook feed today...

Coaster Skiing!

It's been a while since I've seen that. He's done this on many coasters.

What I find most interesting is that he has wheels on the outboard side of the track which is not designed as a running surface.

That looks so incredibly dangerous. There's a SBNO coaster at Kings Island that'd make a nice black diamond.

No upstop?

Just from my observation, it looks like there are upstops (and guide wheels) on the inner rails and the outer guide wheels keep the contraptions from sliding sideways toward the center of the track. This isn't like a coaster car that has an axle to keep each set of inner guide wheels equidistant from each other.

The *trick* solved with the outer wheels is that it forces maintaining proper leg spacing to stick to both rails - one leg drifting inside could be disastrous.

It's the exact opposite of Foster Friess and the aspirin.

Looks to me like there is a lot that could go wrong, even with the solved issues mentioned above. It would probably take superhuman leg strength and impressive balancing powers to prevent him from falling forwards or backwards, or from allowing one leg to travel too far ahead or too far behind.

I do not like this. lol

Ah, you're right Vater. Here's a photo from a different angle.

I'm guessing the ski poles activate the brakes. I wonder if this guy had anything to do with this patent from 1999.

Anyone know what coaster that is?

I've seen pictures of him doing it on Mammut at Tripsdrill.

Pretty sure these pictures are from Mammut too.

With the background in the image, I would say it probably is Mammut. Which is a very smooth coaster with virtually no airtime. Which probably makes it a good candidate for what he is doing.

Here is a similarly angled photo from RCDB
http://rcdb.com/4065.htm?p=21649

The other question is how he prevents himself from valleying. I'd assume that friction is going to affect him a whole lot more than it affects a multi-ton train.

For starters, he has fewer wheels generating friction (but, interestingly, with shorter radii, so they turn much faster.)

I just looked a pictures of Mammut. Looks like a nice ride. I know a little German (He;s standing right over there!) but does "Mammut" mean "mammoth" in English?

I remember seeing one many years ago, where a professional athlete did this on a corkscrew roller coaster. It was called revolution, and had a vertical loop. But, wasn't much bigger than the corkscrew at Michigan's Adventure. I think this might have been before they came out with the first stand up coaster.

The whole idea of that show, was to see how riders would react to riding on a stand up roller coaster. But, obviously the man who actually rode the coaster on skis, did it the same way as what is in the photo Mobius posted, only with actual snow skis on his feet, with wheels attached to them.

People who Ski professionally know exactly how to lean and take curves, and pretty much any terrain. Some ski off the sides of mountains, with drops higher than any normal roller coaster, and probably go just as fast, some even faster. 60 to 80 miles an hour easily. But, I would bet, on a single person on a roller coaster would not experience the full effect of a train load of riders. The weight of the train has a lot to do with it's speed.

But, for the average person to do something like this, they would probably get seriously injured or killed. But a to someone who does it regularly, some coasters are probably pretty tame. I think doing the Voyage would be on the top of their most extreme list.

Brian Noble said:

For starters, he has fewer wheels generating friction (but, interestingly, with shorter radii, so they turn much faster.)

I'm pretty sure (since friction isn't a function of the surface area) that the number of wheels doesn't really affect the amount of friction. I would think wind resistance would play a much bigger role and he's a heck of a lot lighter than your average coaster train with approximately the same cross section.

Wouldn't he also have a lot less momentum than a train?

If you watch the video, he leans down very close to the track about halfway through the circuit to minimize wind resistance.

I'm pretty sure (since friction isn't a function of the surface area) that the number of wheels doesn't really affect the amount of friction.

After doing a bit more reading, you are right---more wheels redistributes the same amount of weight across more space. But, the train is much heavier than a person, and I'm guessing that the mass/axel of the train is a lot higher (and therefore frictional torque is also higher) than the mass/axel of the person---assuming identical wheel designs, yadda yadda (which they aren't). The person also has probably about the same wind resistance, give or take, as a train with seated passengers does (and, possibly less with that tech suit on *and* without a big flat front surface). Plus, as noted, he can tuck.

The short version is: he reportedly made it around. One could work out the physics as to why, but I probably won't. :)