Colvin Motorcycles is a race focused full service shop based in Oklahoma City. Complete Dyno Services. VDTRA TECHNICAL ENTITY. Complete multi line custom and performance builds. Dealer for Sherco Motorcycles. One off racing and street motorcycles built on most all realistic budgets. Dealer for Maxxis Dirt Track tires, Complete line of suspension services, Dealer Direct for Grand Prix Speedworks body work, carbon Fiber and fiber glass, Performance Coatings, magura products, The Spring maker direct sales. COLVIN MOTORCYCLES NOW OFFERS OUR OWN LINE OF PERFORMANCE PIGGY BACK REAR SHOCKS.