Vespa gearboxes

[rosscla]

How many Vespa gearboxes are there?

What's the differences?

I have the Haynes manual but it goes by ratios and they broadly seem to be the same but I'm guessing this might be because the drive cogs vary.

[LI150]

The Vespa gear calculator will give you a good indication there is a link on here.
Then don't forget all the Drt options

[mick1]

also....there are 2 sizes of xmas trees. the end shaft that sits in the casing comes in 2 different sizes

[rosscla]

Ok maybe should have added some context.

I'm scrapping spending any more on the 166 engine that was in the pig. I couldn't get it set up right for some reason.

I'm negotiating for some P2 casings, I wondered if I could use any of the gear box which I was sold as Italian PX125.

What else can I recycle, so far I figured hub, brake, stator, flywheel, clutch, carb.

[oldbiker]

scooterhelp gear calculator etc.

[rosscla]

It looks like the final ratios are similar but how you get there is determined by the box and the primary drive combination.

Best to get a Gearbox too

[gaz_powell]

this is useful

http://beedspeed.com/html-pages/GearRatios.pdf

gaz

[Yanker]

I'd move the box over if PX EFL and not P125X.

Install PX200 primary gears.

You will need a better clutch anyway unless it is the later Cosa type.

So subject to type of tune (I am somehow convinced that there will be one!), investment suggestions for more appropriate primary gearing combinations can be made

[rosscla]

Cheers guys, that chart certainly makes it look like there's little difference between the dog in the box so the main difference is the primary's, which I guess means changing the cog on the clutch and the and the large gear on the Xmas tree?

I've not played much with this sort of thing with vethpas, just used to run them as they were.

[GLscoot]

SIP is probably best to check what gear, clutch and primary ratios are best suited to each other.