Add Yahoo as a preferred source to see more of our stories on Google. So it's time to buy some new wheels. What hardness should you get? What do the durometer numbers mean? What's a durometer anyway?

Instron Corp. is marketing its new Shore S1 Durometer, which features a modular cartridge system. The system allows operators to test in any of the standard Shore scales-A, B, D, C, DO, O, OO and M.

So it's time to buy some new wheels. What hardness should you get? What do the durometer numbers mean? What's a durometer anyway? Don't worry, we got you. All skateboard wheels are made from urethane, ...