>>8157492>how much sanding.Well, personally I never sand anything. I use the nippers to cut the nub and then use a hobby knife to shave off the remaining bit. I think it produces fine results.
>What material are the wheelsThe actual black part of the tire is rubber, while the inner part is plastic. The rubber parts come separate and are placed on the rim. Here's an example.
https://www.1999.co.jp/itbig54/10549363n4.jpg 