[sanddrag]

Originally Posted by Andrew Blair

How were your axles supported so as to keep them (and the frame/support device) from bending?

You can sort of see in this pic. The frame side rails are 1.5x2x1/8 6063 aluminum box tubing. Pockets were cut in the sides of the frame rails for pillow blocks to go in (and slide). The pillow blocks had 1/8" that went into the pocket in the frame rail and 3/16" that rode outside on the surface of the frame rail. There is a pillow block on the outside side of the frame rail and on the inboard side. We used standard 1/2" id flanged ball bearings from Small Parts and 1/2 precision keyed shaft from McMaster. The wheels were custom machined from solid 6061-T6 blanks and the spokes are 1/4" thick. Surprisingly, the wheels bent and would run out of true since there was no real 3rd dimension to the design of the spoke other than its thickness.

So putting it simply, you have a frame rail. You have a live axle go through it. You have a bearing on either side of the frame rail. You have a wheel outboard and a sprocket inboard.

For the frame rails, we could have gotten away with only 1" wide instead of 1.5" like 22, 254, and 968 (and probably others) do.

Edit: Here's another good pic of the setup.

The outboard pillow blocks had through holes and the inboard pillow blocks had threaded holes and the screws went through the frame rail and they clamped together onto the frame rail.

Let me know if you have any further questions.