Team 868 fabricated wheels like that for the 2006 game, Aim High. We were not able to go up the ramp at any angle other than head on, and once on the ramp we were not able to strafe from side to side, there was too much slippage.
Here's a picture of one of the wheels:
http://i111.photobucket.com/albums/n...te/5wheels.jpg
To be fair, I believe the ramp surface that year was diamond plate, so with a different surface you may have different results.
Best of luck.
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