Markings on coaster wheel question.

While at michigans adventure this week, I noticed these markings on thunderhawks wheels. Any idea what they are for?

http://coasterbuzz.com/Forums/Thread/57579.aspx?id=811749

Also, this is the only slc I have seen these type wheels on. This is the smoothest slc I have ever been on. Does the fact that these are non vekoma wheels have anything to do with that?

Asked this same question over at PointBuzz a month ago or so. Really got no answers. They seem to have thought it was some kinda of clearance for axles sitting on the bearings. But, I really don't know. At least you got a pic of the numbers, that I didn't.

For numbers that are that small, I wonder if it is the amount of unbalance on the wheel...

Of course we still don't know the units.

--Dave Althoff, Jr.

I wouldn't imagine you could get away with that much axle clearance on a bearing, it would destroy the bearing. Millimeters maybe, not inches. Probably in the unit of measurement that the maintenance personnel are most familiar with.

Dave, Out of curiosity, How would you check the balance of a wheel when it's under operational conditions/loads?

I would assume that the numbers are the warpage of the wheel. 6 and 19 thousandths are not that much of a variation. The wheels will never be true and will have some variation. I would think that with this info they would match it's location to get the smoothest ride.

If the measurments are in thousandths, which I assume they are. They signify either the warpage of the wheel or the difference between the axle shaft and the bearing hub. .019 is not that much, it would most likely just make the axle shaft smaller in diameter for next year.

Or I just maybe speaking out of my a**. I am not able to tell which some days.

I have been on almost every slc in america and canada, and this is the only one that I have seen these wheels.

The slc in michigan, is by far the smoothest and has the least amount of head banging. Do you think that the wheels would make that much of a differance?

I am kinda curious, since this is the only coaster I have ever seen numbers on the outer assemblies. Do the maintenace crews put them on all coasters and we just don't see them. Like maybe on the inside whell hub. Crazy Horse, was Thunderhawk that smooth in Gauga Lake?

Yes.

But from what I hear, it has improved slightly since it's move.

Yeah, once Cedar Fair took over at Geauga Lake, the ride got significantly more rideable. Made me think briefly that the SLC wasn't inherently bad.

What I heard was that there was some issue with Vekoma wanting to sell all new wheels for the SLC at some ridiculous cost, and Cedar Fair found some shop that was willing to fabricate new wheels to Vekoma's specs (I don't think Uremet made those wheels; they just put the tires on them). A well-placed person explained it to me in some detail, but I don't remember the whole story anymore.

Oddly enough, I recall seeing Arrow wheels on the SLC at Adventure World, so apparently Vekoma's specs are remarkably similar to Arrow's specs, which is not surprising. But these solid disc, unspoked wheels seem to be unique to this particular SLC.

The SLC in question has always been the best-running SLC I've ever ridden, and back in the pre-Six Flags days it was the only one I ever saw where operations were so quick that it could have actually benefitted from a third train. Meanwhile, I think Kentucky Kingdom's was the only one that ever *had* a third train. Or at least I thought it did...

--Dave Althoff, Jr.

It might be the TIR (total indicated runout) of the wheel. Or in layman terms how far out of round the wheel is. Then they would know what it started out at and can compared it to what it is after the wheels wear.