Modern Vespa

Anyone tried the BENELLI 5 speed Gearbox Kit for large frames?

PX cruciforms wear out quickly enough, without making them any thinner.
Can buy a lot of extra torque and power to pull 4 gears faster, for less money.

But if you want to run higher speeds with lower rpm it could be the way to go?

They are expensive, so Just wondered if anyone had taken the plunge.

It won't do what you think. If your power doesn't match your gearing, it can be fixed within 4 gears.
5 Gears on a PX, is for very high performance cylinders with narrow powerbands. And riders who ride very little, with money to waste.

5 speed transmissions doesn't automatically mean that it gives you an overdrive gear. Most of them are designed to have the same top gear ratio as a wider ratio 4 speed transmission, but what it's designed to do is give you a close ratio transmission in order to keep you in the power band. And usually when you do that, you can kinda upgear the clutch tooth in 5 speed transmission a little bit in order to lower your rpm a smidge.

All that is NOT worth it in a vespa! The transmission is not strong enough! If you have a high torque engine build, you're better off installing a 36t short 4 gear and a 24 tooth clutch.

Unless I misunderstood a 24/65 with 36 tooth (T5) will be shorter gearing than 23/65 with 35 tooth standard setup for a P200.

I'm looking to reduce my current 80mph 8000+ rpm by at least 1000 rpm and not lose too much in acceleration.

Hey Andy,
Did you get any further with your 5speed GB enquiries? I'm VERY new to tuning Vespas, so please go easy on me 🙏🙏

I've just built a Polini 221, reed block, Mazuchelli bell crank, 28mm Dellorto, 24tooth clutch gear on to a 65tooth??, BGM touring pipe and it rides right nice, but dies on a steep incline (s up and pannier bags)which is mildly irritating.

I have a Lammy with an Imola kit & the usual tweeky toys on it running a Clo5e gearbox, which I find excellent, in that on a similar steep incline, if needed I can drop it into 4th, which is very close to 5th and it still pulls nicely, MUCH nicer than having tto wait till the revs drop low enough to use 3rd where it's then revving its tits off, before slumping into fourth again.

If I could replicate the Clo5e gearbox experience in my Vespa I would be VERY happy, but at nearly €2k it's an expensive experiment if it doesn't work right.

I see the other lads saying there enough 4speed GB options available, but I don't see how they get me over my issues