Hallo all vespafan…
I would like to know a simple thing, that in Italy
is hard to find!

I need to know about the gearing of the px 80 cc.
Fox EX: the teeth of 125 cc are
first gear: 12/58; second: 13/42 etc…

what about the px 80???
someone knows about it???

thanks to all!!!
-excuse my english-

Hallo doctor!!!
I’m not lucky…
There’s nobody who is really sure about that!


eh eh!!!

trust me whatever motor you kit be it a 125 or 200 if your engine wont pull standard 125 gearing from 3rd to 4th then there is a serious problem with your setup.if you up the compression on a standard px125 to 125psi it will pull65-72mph without any other modifications(but the piston will melt).any kit 166/172/sip200/210/225 will pull standard px125/t5 fourth from 3rd i say i think the difference on the px80 is on the primary gear so if you fitted on into a kitted 125 say polini177 it would rev the nuts off itself in 3rd and 4th but your terminal speed in 4th would be about 65mph so no use at all.if you could enlighten me as to your engine and desired setup i would be glad to guide you toward a good fast and reliable setup that i guarantee will pull 4th whatever you have in mind

stroud valleys(midnight hour)sc est 1984

i think you’ll find the gearing is the same in the box i.e. same amount of teeth on gears and xmas tree.if there is any difference it will be on the primary gear

stroud valleys(midnight hour)sc est 1984

as noone seems to have this info the only way to find out is to get a px80 and strip out the gear box.they arent commonplace in england so havent had much experience with them,sorry! good luck

stroud valleys(midnight hour)sc est 1984

PX 80 gears are totaly different from the 125.

  1. gear 80 10/no idea, we don´t have it
    2.gear 80 14/55 teeth
    3.gear 80 19/50 teeth
    4.gear 80 23/37 teeth
    The input shaft 80 is a different like on all others, it´s a special PX 80 one
    Primary transmission is 20/68

Hope this is a little help for you![;)]

No it´s 10-14-19-23

Inputshaft is different from the 125/150/200.

[:drink:] Daniel

thanks a lot!!! [:dance2:]

i believe 80-125 are identical but 150 is different

stroud valleys(midnight hour)sc est 1984

out of interest why, inparticular, are you looking for a px80 gearbox??why not start with a 125 box for ease as thats low enough and gear upable enough for any px engine build.why would you need anything lower if thats why youre looking?? or do you have a px80 with a shagged box

stroud valleys(midnight hour)sc est 1984

If I had a px 80… eh eh I would know the gearing… :slight_smile:

Only I would like to know it not for the primary gearing,
but about the Jump between the 4 gears.

If I have a High rpm cilynder, and use the px200 gearing with 4th
short of a PX125 or T5… I’ll always have too much difference between 3th and 4th gear…

So I’would like to know about the px 80…
May be the gearing of this model (that I’ve heared is different from all other px) can help me…

But nobody knows how much teeth…
[:@] [:@] [:@] [:@] [:’(] [:’(] [:’(] [:’(]

From the first gear i don´t know the teeths, but it´s very very short, so it´s only useable on a org. PX 80. [:dance2:]

Have you tried a lower profile tyre? might lower the gearing enough and if it dosen’t easy to change!
Also try getting hold of the vespa tunning book by norrie, as its got the gearbox’s ratio’s in charts which might help

Hallo doc.
Now i’m interested in small-frame.
But some years ago, i had a px 210 Polini,
all tuned by Scauri!
This „small-frame guru“ didn’t like px motors eh eh,
but we were and are friends.
So when i had a px crashed his neuros system and I convinced him to tune my p200.
The first cylynder was very VERY powerful at high rpm and
with 4gear t5 and malossi 23/64
in 3rd gear it was about 120 km/h.
but then the motor can’t reach rpm in 4th gear.

Oh… we used a 28 phbh carb. and Zirri exhaust.

So then we put a original primary and a less phased cylinder,
so we solve the problem but the rpms where lost.

And now in my px there is a „ordinary“ 177 polini, and all goes
right but
it was my dream to know about an alternative solution to the gearing.
and may be lift the phases in this polini 177 up to 9/10.000 rpms!

[:smile:] [:smile:] [:smile:] [:smile:]

You are great!
Now i need only the other teths of the other 4 … cogs (is this the word?)

or are they like 125/150?

For you i have the gearing Pinasco 1978-85…
12/58 - 16/42 - 20/38 - 21/35
hope you like it!!!

So should I be sure that the gearing are the same for px 80-125-150…

I thought it was different, cause
in the catalogue the cogs (?) have different serial numbers.

I know that 125 cc could have different gearing…
the first series have old tipe of teeth like SV150
and the new models (in de called EFL) have larger teeth.
But the difference is not very important.

So… this was my dubt…
eh eh

Anyway thanks for the answer!!!

Hallo doctor,
even in italy there’s no px 80 available…
hope that someone German has the answer!!!

Thanks doc.
Did you see ?
take a look!

oh great!!!

so this you give is the 80 gearing…??? [:bounce:]



Now I have to calculate…


see yo soon!!!
[:drink:] [:roll:]