Recently we bought you news of Motorino Diavolo’s interesting sequential gearchange system for large-frame Vespa. In parallel, Casa Performance has been working on a similar system for Lambretta.
What is it?
This is an adaptor for converting any Lambretta LI-series engine to sequential gearchange. The assembly sits on top of the engine in place of the conventional gear cable arm. It will also require a dedicated cable adjuster block, revised clutch arm and length-adjustable tie-rod.
The project is an extension of the sequential system that the Casa Lambretta team have previously used on their racing scooters, but those systems were mounted in the handlebars and therefore difficult to adapt to road use.
Behind the idea
The sequential gear mechanism was originally intended to compliment a forthcoming hydraulic version of the new CasaCover side casing. With a hydraulic hose there are no problems of cable run past the mechanism.
The sequential components are also no problem with the normal cable type CasaCover which employs a much shorter clutch cable arm. With this, the clutch cable run will not be obstructed by the sequential mechanism.
For use with original side-casings, a specific clutch arm and cable adjuster block will be required.
State of play
At the moment the system is working in 3D printed prototype form. Development has now moved to metal parts for testing.
The clever thing about this design is that swapping only one component allows you to adjust the selector to work with either 4-speed or 5-speed gearboxes.
VIDEO: Lambretta sequential gear prototype mechanism
What does it do?
This system converts the handlebar gearchange to work like a motorcycle gear lever, so every time you shift gears, you only rotate the handlebar end a restricted amount, and each time the clutch lever returns to the same position.
With this system each shift has a positive stop, so it is impossible to go from 2nd to 4th gear by accident. Also with a firm movement of the bar end, the gears will shift from 1st to 2nd gear without the possibility of ending in Neutral.
To select Neutral you must make a gentle half-movement from either 1st or 2nd gears, again like on a motorcycle.
What is the point?
There are several types of scooterist who might gain from sequential selection, Vespa or Lambretta:
- Racers looking to improve lap times.
- Sprinters and tuners looking to avoid missed gear selections.
- Those fitting a 5-speed gearbox who might struggle getting used to the small movement required compared to a 4-speed gearbox.
- Anyone who no longer wants to worry about missed gears.
- Anyone with limited wrist movement.
- Anyone wanting to convert to push-button gear-shift.
- Anyone wanting foot-lever gearshift (e.g. chopper builders).
When and How Much?
It is too early in the development process to give a definitive answer to these questions, but with the incredibly rapid pace of development at Casa Performance I don’t expect it to take too long, or the cost to be much different to Motorino Diavolo’s Vespa version.