Input Shaft Assembly 20-17-14-10 teeth DRT 4-speed/PK RUNNER

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 RUNNER input shaft assembly: It possesses shorter 3rd and 4th gears that do not require the use of differently sized gear cogs on the output shaft. The second simple and effective step into the world of gear box ratio tuning.

The DRT RUNNNER input shaft assembly has gear cogs with 20, 17, 14 and 10 cog teeth respectively which makes the 3rd and 4th gear ratios shorter. The OE PIAGGIO 3rd and 4th gear cogs on the output shaft can still be used in combination with this conversion kit. This input shaft assembly conversion enables uninterrupted acceleration through all gear changes and is especially suited for motors with a cubic capacity of between 100 and 130cc. It is very good in combination with the 1st gear for the output shaft with 55 teeth produced by DRT (Art.-No. 40431710) and the very short 2nd gear, also by DRT, with 55 teeth. Performance orientated motor setups can also benefit from the use of the DRT 2nd gear cog with 52 teeth, the DRT 1st gear cog with 54 teeth and the DRT 3rd gear cog with 49 teeth. The 4th gear cog which is an OE PIAGGIO item with 50 teeth does not need to be changed. 

The input shaft assenbly RUNNER RACING is produced for SIP on special request. It is made of best german steel. Difficult to modify, very tough and needs a special heat treatment i production. This steel is the best material DRT gets to make gear kits.

For High-End engines >25PS DRT strongly recommends the use of the RSP series.

DRT has the following input shaft gear ratio recommendations:

POLINI 100cc, 2.88 = 24/69 or 2.86 = 21/60 gear cog tooth combination

POLINI 130cc, 2.55 = 27/69 or 2.61 = 23/60 gear cog tooth combination

QUATTRINI M1/M1L/PARMAKIT, 2.73 = 22/60 or 2.76 = 25/69 gear cog tooth combination

Conclusion: Shorter 3rd and 4th gear ratios without having to change the output shaft gear cogs. A simple and effective second step into the world of gear box ratio tuning.