RMS Vespa Clustershaft 12-13-17-21 (67 Tooth Primary Drive) P125-150, PX125-150, Cosa, T5Piaggio Vespa Clustershaft 12 13 17 21 (67 Tooth Primary Drive) P125 150, PX125 150, Cosa, T5 Vesoa Clustershafts are a pre assembled part that comes with a 67 tooth primary gear, suitable for the Vespa PX 125 150 gearbox. Standard Vespa PX125 150 has a primary drive of 67 68, while the PX 200 version has a 64 65 primary drive. The primary drive has to match with the internal clutch gear (compatible with Cosa and Non Cosa Clutches) The Clustershaft