This isn't anything special, but this is just a little doodle I got a chance to do at work. I've always been a fan of Sonic Riders and I never got a chance to play Free Riders, but the gear was cool and I made a couple of designs from a few types of gear

Mario (Red Fire)-Based on the Blue Star
Tevante (Blue Rocket)-Based on The Fastest
Luigi (Green Bolt)-Based on The Beginner
Mark (Aqua Cruiser)-Based on the Turbo Star

The other 2 are team members I haven't shown up here yet.