Pull the side cover off a race gearbox and the first surprise is that nothing ever slides into mesh. Every gear pair is already engaged, permanently, all the time. Constant mesh means the ratio you are not using is still turning. On each shaft some gears are splined solid, while their partners spin free on needle rollers or bronze bushes, decoupled from the shaft they ride on. Selecting a gear does not move teeth together. It drives a set of blunt lugs called dogs into the matching pockets of the neighbouring gear, locking that gear to its shaft. The choreography comes from one steel cylinder and a handful of parts: - A shift drum with helical tracks milled into its outer surface - Shift forks riding those tracks, converting drum rotation into axial travel - A detent star and spring, holding each index so the drum cannot stop halfway - Undercut dog faces, angled roughly five to seven degrees, so torque pulls the engagement deeper instead of spitting it out There are no synchroniser...