More information about ST Racing Replacement Shoes/Flywheel Revo Blue STRST4142XBST Racing 3 Piece Shoes/Flywheel Blue for the RevoThis option part is a must for serious Revo 3.3 MT racers. This complete kit includes a light weight CNC machined aluminum flywheel (40mm size for bump start use), CNC machined aluminum clutch shoes for precise clutch engagement and feel, special clutch nut for 3-shoe setup and matching tension clutch springs. This complete clutch upgrade will enhance the performance of your Revo 3.3 while also allowing the use of bump start to start your engine. Anodized in Royal Blue. Replacement clutch springs and shoe set (ST4142C) is also available separately for rebuilding your clutch.