I had heard Millennium Force changed wheels every morning when it opened in 2000. Intamin changed the wheel compounds and sent out new wheels to CP, so I don't know if they still change the wheels everyday.
Canadas Coaster Drew said: Would these be the wheels on Thrust Air 2000's? ----------------- http://flatrides.gq.nu
Nope, I'm sure regular coaster wheels get replaced MUCH more than on the TA2K. Those are aircraft tires. Do you know how much wear and tear those things go through on landings? They last a while too. I bet the demands the TA2K puts on them are small in comparison.
Just about every coaster has at least a complete inspection of the wheels each and every morning, and the majority will probably replace a wheel or two a day. Viper at sfgadv went through all sorts of wheels, even sometimes more than 1 change a day!
Yea, usually a couple wheels get replaced each day on Magnum. We always hoped that they'd get any of the "suspect" ones during night maintenance, but despite that, on probably about half of the days, we'd go down for about 10 minutes to have a wheel or two changed. If you hear the crew announce a "short delay" in the station, it is most likely for a wheel.
...Particularly if the ride goes down just as a guy in a blue shirt shows up on the exit side of the platform, and you haven't seen any obvious problems with the ride. :)
It's instructive to visit Kennywood. On the big steel coaster, they mark the replacement date on the outboard side of the wheel. At one point I was about to board and I noticed that there were wheels with dates indicating that they were a couple of years old, and there were dates indicating that wheels had been replaced that morning. Apparently, how often a wheel has to be replaced on a given ride depends on where the wheel is located on the train. Some wheels last a long time, some wheels don't.
Yea, that's definitely true Dave. I know the back road wheels on Magnum seemed to get changed more than others. Other than those though I wasn't observant enough to notice any pattern to it - especially since alot of changes get done at night.
Sometimes when people asked what was wrong we told them that it was a "flat tire" :)
Sometimes it literally is a flat tire. One of the ways the wheels can fail is that the bearing will seize and the wheel will stick, sliding instead of rolling, and wearing a flat spot onto the plastic tire. Also, on many coasters, guide wheels and upstop wheels take a beating when a stopped wheel crashes suddenly into the track while the train is running at high speed...that will cause the tire to deflect, ultimately to wear unevenly, delaminate from the wheel, and otherwise fail.
What you call "normal wear and tear."
By comparison, wood coasters run all-metal wheels. Those are sometimes refinished (much the same way you might refinish the brake discs on your car) but I know that as of about four years ago, Kings Island's Racer was running almost all original wheels.
The whole thing is interesting to me because I would think by now that there would be such high-tech polymers that this wouldn't be an issue anymore, but obviously it is. Do you think it's impossible to develop some kind of polymer that is reasonably soft, but resistant to melting?
----------------- Jeff - Webmaster/Admin - CoasterBuzz.com, Sillynonsense.com "As far as I can tell it doesn't matter who you are. If you can believe, there's something worth fighting for..." - Garbage, "Parade"
Soft and resistant to melting is cake... silicone.
Soft, resistant to melting AND resistant to abrasion... well that's another story. With a good coefficient of friction usually means urethane.
Realistically though, I think the wheels are designed to be as gentle on the track as possible, as opposed to being as long lasting as possible. Changing a wheel can't cost them more than twenty bucks in materials and labour, whereas the structure of the coaster cost millions.
STE started using metal wheels I think to prolong their life. I had heard that they got too hot when they were using the polyurethane ones. All I know is that with the steel ones that thing is loud! You can hear that thing from the opposite side of the park! ----------------- "If somebody throws a rock and knocks a man off his donkey, do we say that he's stoned off his ass?
I don't have any actual numbers, but a wheel change costs more than $20 with labor and the need to refurbish the wheel. As Dave said wheel life varies all over the place as does the demands on the wheels. Just look at some of the latest Intamin wheel sets that use as many as 4 different types of road wheels to match the wheels to the service. And, that doesn't count upstops and side wheels.
The problem with soft wheels is they inherently develop more heat than hard wheels due to the greater deflection of the elastomer. This is the greatest problem for road wheels since they take the heavy G's. While bearings do fail, most wheel failures are due to chunking of the elastomer on the wheel. A chunk of missing elastomer results in the thump thump that you feel when you ride a train with a "square" wheel.
I don't have any good numbers either, and part of the problem is that if some television producer quotes you a price for a coaster wheel, he's giving you the cost of a new wheel. Most parks don't use new wheels unless absolutely necessary...the wheels on Magnum XL-200, for instance, are aluminum with a bearing pressed into the center and with a 5/8" polyurethane tire around the outer rim. The bearings and tires can be replaced as needed, and I'm guessing that the refurbishment cost is significantly less than the new wheel cost.