Input Shaft Assembly 21-18-14-10 teeth DRT 4-speed/PK

Clean gear changes while you are accelerating can be decisive over defeat or victory. It is almost an art to be able to setup your gear ratios ideally to match the area of your rev range where maximum power is available (the power band). The VESPA gear box components have seen a lot of experimentation and development in recent years. DRT are at the forefront of this research and have suitable gear box parts available to suit most possible motor setups.

The problem of a clean gear change between 3rd and 4th gears, especially with performance enhanced motors, is shared between both the large and small frame VESPA motors. DRT offers new gear ratio setups with their range of input shaft assemblies. Maximum engine revolutions in 4th gear with a 150 kg load over a longer distance or race use of the 4th gear, everything is possible.

DRT input shaft assemblies are made of a tougher than standard grade of steel and then hardened through tempering. They are therefore extremely durable and so offer an ideal extension to the vast range of existing gear box components available. The gear ratios are much easier to adjust to the particular motor characteristics required. Most of the input shaft assemblies are equipped with a fine M11 grade thread and the nut to fit is also included.

Conclusion: These DRT input shaft assemblies are essential for all serious racers and sprinters. Rally going scooterists have also learnt the benefits of top quality adjustable gear box ratios.

SIP-TIP: If you want to raise the ratio of your gear box start with the primary drive gears. The input shaft upgrade is first, followed by the adjustment of the individual gear cogs on the output shaft. Never forget to order a new gear selector cruciform (at best the DRT item) and fresh gear box oil. Last but not least the SIP gear box shaft assembly spacers help you find the ideal output shaft assembly end float for safe and enduring use of your motor.

You can choose from the following DRT input shaft assemblies:

The DRT input shaft assembly 'short 4th gear/ PARMA': A shorter 4th gear can be achieved but only in combination with the PARMA 4th gear cog for the output shaft with 47 cog teeth. This conversion kit is intended for use by those of you who find the regular DRT raised 4th gear (Art.-No.40430313) too short for their requirements. This input shaft is designed for motors that need a very tall 4th gear and also enables the rest of the gear ratios to be more finely tuned for better acceleration up through the gears. This kit is based on the original product by ZIRRI, which was for a long time the only alternative to the standard item. Then thanks to small frame VESPA racing becoming popular again in Italy, DRT concentrated their efforts on high end VESPA gear box components. These input shaft assemblies are available with either 21, 20 or 19 teeth on the 4th gear cog.

Conclusion: For all who need a taller 4th gear than the already taller than original 4th gear cog also produced by DRT (Art.-No.40430313).