[mman1506]

We used 30a urethane for our intake wheels. We didn't do any scientific testing but we compared them anecdotally with fresh Vex colsons on carpet and if anything the colsons were grippier on carpet. After testing a number of durometer samples 30a is as low as I would go for any function. The urethane also tends to get covered in tread dust that significantly lowers traction.

They worked excellently as intake wheels though and we definitely plan on using them in the future for other functions.