[Kevin Ray]

Monochron Let's take those wheels you, DonShaw, posted as an example. Most have a 5/16" bearing in the center. The Kit chassis has a 3/8" hole for front and rear axles. Ideally the 5/16" bearing can be swapped for a 3/8" bearing, but there is no bore size listed on that site. If the bore size is 0.865" I assume the team would have a problem with fit for the bearing? Is this correct?

If the above problem is solved, now we have to mount the pulley to the wheel. It looks to me like the screws already in that wheel will interfere with the AM pulleys mounting holes. Is it worth it to go without the mounting holes that interfere? Also, drilling and accurate hole in that slope looks challenging. Can you give any recommendations for keeping your holes straight and within reasonable tolerance when drilling at such an extreme angle?


And just to make this a bit more broad, can anyone suggest methods for wheel that come without a useful bore size? Such as wheels whose bearings don't naturally fit with the KOP bolts? Re-drilling a drivetrain mount point poorly can wreak havok on a low-resource team's season. Any suggestions that make attempting it more worth it than simply waiting for backordered parts?


Okay, having been around since 2000 with the original Skyway wheelchair wheels and having the above only the mentioned tools (or lack of proper tools) we are somewhat competent at helping minimalist teams compensate for the lack of "prefabbed" drivetrains. Thankfully, we have come a long way since.

The first thing to address in adapting the pneumatic wheelchair wheels to this year's game is the bore size. We insist on 1/2 inch shafting (always captivated on both sides of the wheel) for all drive systems--especially this years game!!! If the bore is smaller than 1/2 inch you'll have to modify it; easy enough to do. First purchase 1/2 hubs (with the bore (hex, round-keyed) matching the output shaft of your drive gearbox from AndyMark or such. Second, align the hub over the wheel and insert a shaft matching the size of the wheel's bore through the hub and into the wheel. Insert a spacer around the shaft to fill the space in the hub. This ensures that the hub remains centered. Mark, drill through the hub's holes into the wheel and bolt the hub to the wheel. Now, unbolt the hub and remove the smaller bearing in the wheel and replace the hub. It is STRONGLY advised that a second similar hub be placed on the opposite side of the wheel to captivate the wheel since the shaft is now "free floating" in the bore hole created by removing the original bearings. This can all be accomplished with nothing more than a drill press and wrenches. Please note, the center of the hub (the top hat part) should be inserted into the newly created hole in the wheel's center as close to a press fit as possible.
P/M me with questions on how to easily drill out any size hole to ensure a tight fit for the hub (using only a drill press).

...hope this helps.