Small primary gear -DRT Gear Flame Cobra 20/60 (3.00) - Vespa V50, PV125, ET3. PK50, PK80, PK125 - 20 tooth (straight)

The always with catchy names provided components of DRT have a very good quality, even in the hardest racing use gives up to now as good as no defective of the parts to register. This is a miracle in itself, if you consider that the original gearbox is designed for only 8-9hp at the rear wheel.

Meanwhile there are quite a few engines that have more than 40hp at the rear wheel.

DRT offers here the suitable parts and makes the life of a Vespas wrench much easier, especially because of its modular constructed gearboxes.

The Cobra primary consists of a specially manufactured clutch pinion with 60 teeth. So you can use the same clutch pinion either a long 2.61's or a short 3.16's reduction plus the possible steps in between.

For this you always had to disassemble the complete motor before because it was always necessary to exchange the complete primary.

The Cobra sprockets are available in five versions, which results in the following primary reduction ratios with the 60 tooth Cobra clutch pinion:

• 19 teeth (3.16)
• 20 teeth (3.00)
• 21 teeth (2.86)
• 22 teeth (2.72)
• 23 teeth (2nd gear)61)
  
  

For a better estimation of the gear ratio length, here is an example of the primary reduction ratios of some original Vespa engines:

• V50 Special (4,25)
• PK 50 XL (4,00)
• V90/PK80 (2,86)
• 125PV (2,54)

Due to the much higher speed level of a tuned engine it is often useful to use a shorter reduction ratio than the original one used for a similar displacement. Just because an engine has more power does not mean that it can 'pull' a longer gear ratio.

The pinion offered here has 20 teeth and can only be used with the COBRA clutch pinion available with the SEPARAT!