I'm assuming the aero drag from his 'nads prevented faster speeds 
So a quick google search says skateboard wheels are about 60mm diameter. Speedy skateboard wheels may be bigger, but using 60mm, and if my math is correct, at 89.41 mph those little suckers are spinning 12,746 rpm...
OK, more googling says more like 72mm for the downhill longboards. That's still 9756 rpm. Those little bearings are really singin!
He's running 73mm wheels, you can see it at the 34sec mark.
In reply to doc_speeder:
they were 73mm, but still holy berk.
I am glad to see that other people did the math too 
A wheel bearing failure at a buck-forty on a skateboard would be less than optimal, physiologically-speaking.
I figured on 2.5" wheels and came up with 12,5-ish. Angle grinder bearings handle that no problem, but still, them wheels was a'singin'.
(scary thought: I see 10k all the time with my RX-7. An SR Motorsports flywheel is much, much larger than a skateboard wheel. And how fast is the alternator spinning at those engine speeds? What is the surface speed of its brushes on the commutator, or whatever it's called on an alternator?)
Even a cheap 608-2RS (the usual sealed skateboard bearing) is rated for 20,000 RPM, 30,000 for the shielded variant, 36,000 for an open bearing in oil. And those ratings are really more suggestions for a long life.
How the heck do you stop?
you think larger wheels would help him overcome some of his frictional losses? say 100mm?
You would still think that he's generating a lot of heat inside those wheels.
Skate bearings have come a long way from the bearings most remember from their youth and the ones he uses are most likely ceramics with special lube. You can spend well over $100.00 on a set of bearings now.
Not sure I've ever seen an old long boarder. They don't think that far ahead.
I nearly took out two kids last summer on a winding forested road. They are alive because I took to the ditch.
Beer Baron wrote: How the heck do you *stop*?
Beer Baron wrote: How the heck do you *stop*?
That's my question. I assume standing and "dirtying" up your aero helps, but he's got to just ride it out until he goes uphill again.
I wonder how fast he could have gone with the van in front punching a hole in the air.
"Undisclosed location." Imagine getting a ticket for double the posted speed limit on a skateboard. That's one ticket that would be worth getting framed.
MadScientistMatt wrote: "Undisclosed location." Imagine getting a ticket for double the posted speed limit on a skateboard. That's one ticket that would be worth getting framed.
I suspect it's more to keep idiot thrill seekers from trying to replicate the run and killing themselves.
I was a very impressed, until I saw the bends. Then I was blown away.
Sure looks like the black hills in SD. What amazed me is that it was not an arrow straight road; he had to actually steer that thing
JEEZ...2 words:
BERKING SPEED WOBBLES!
just skating down my mile long downhill street where I grew up, if you werent very centered, or leaned too hard or tried to steer too much, you began oscillating left to right in such a way that a browning of your trousers was imminent. I could not imagine what that would be like at nearly 3 times the speeds I was travelling at (we did some rough math, approx 31 mph if the kid operating the stopwatch was right).
This world record attempt was brought to you by the good people at Depends.
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