Re: 9" Diameter Wheels
 

The wheels are actually a lot darker than the photo on the harbor freight website. They are around 2.5 inches wide at the thickest point depending on load and inflation. Actual contact area is around 2-2.25 inches with the ground.Versa hubs could work but it would be difficult to mount them as the hubs are made of steel and the only mounting points are the bolts holding the wheel together. If I had to make hubs again I would ether 3d print them, cast them in a 3d printed mold or depending on if your team has a mill just drill the versa hole pattern and bolt a hub to it. Doing it by hand is possible but idd imagine immensely frustrating to get the hole pattern centered.

Re: 9" Diameter Wheels
 

We have a CNC Mill and have already made Versa mounting hubs for our 7.5" wheels - made by McMasterr that have the exact same type of steel hub. I have no worries about making hubs. At this point my chief concern is the correct diameter and width. 2.5 inches at it's thickest point is pushing it but I think we can fit it. If anyone has any extra wheels with a 2.5" width and 8.5-9.75" diameter we'd be happy to buy them from you. I'm hoping for pneumatic wheels but at this point we're happy with anything we can get.

Re: 9" Diameter Wheels
 

partsforscooters.com

Look at the wheel assemblies. When you figure you get the wheel, tire, tube, bearings, and sprocket it isn't a bad price per wheel. I also found similar wheels from light aircraft suppliers.

Re: 9" Diameter Wheels
 

I went to their website but their sizing is confusing me. I'm assuming the size 3.00-8 is a 8 inch diameter wheel with a three inch wheel? Maybe you know better then me, but all their products seem to be this size.