Smallframe gearing

[ets]

Hi Guys
here follows a list of all the gearing kits I came across in years. Hope someone finds it useful. ;D

(notes: SC=Straight Cut; HC=Helical Cut; WC=With Cush Drive NC=No Cush Drive; St=Steel; AL=Aluminium)

14/69 4,93 HC NC St - Piaggio (Rush 3 m, HP)
15/69 4,60 HC NC St - Piaggio (PK 50 4 m)
16/69 4,31 HC NC St - Pinasco Drive Cog+Piaggio 69 Teeth primary (see above)
16/68 4.25 HC NC St - Piaggio (50 N 3m)
18/67 3.72 HC NC St - Piaggio (Vespa 50 3m 9" Wheels) Olimpia, Cif, RMS
18/67 3.72 HC NC AL - Newfren
18/67 3.72 SC NC AL - Newfren
21/76 3.62 SC NC St - Cif per Vespa HP, V
18/65 3.61 SC NC AL - Polini per Rush 3 m
19/67 3.52 HC NC St - Piaggio with DRT Drive Cog
22/72 3.27 SC NC St - Rush 3 m
24/72 3,00 SC WC St - Olympia, Cif, RMS
24/72 3,00 SC NC AL - Pinasco, Newfren
21/62 2,95 SC NC AL - Polini
22/63 2,86 HC WC St - Piaggio (Vespa 90), Olympia, Cif, RMS
22/63 2,86 HC NC St - Cif per Vespa HP, V
22/63 2,86 HC NC AL - Newfren
22/61 2,77 HC NC St
23/60 2,61 SC NC AL - Polini
27/69 2,56 SC WC St - Olympia, Cif, RMS, Pinasco, Polini
27/69 2,56 SC NC AL - Pinasco Newfren
24/61 2,54 HC WC St - Piaggio (ET3, 90SS, PK 125), Olympia, Cif, RMS
24/61 2,54 HC NC St - Piaggio (Vespa PK 125 V)
24/61 2,54 HC NC AL - Newfren, Pinasco
24/58 2,42 SC NC AL - Polini
25/59 2,36 HC NC St
29/68 2,34 SC WC St - Olympia, Cif, RMS
29/68 2,34 SC NC AL - Pinasco, Newfren

[225worb]

Hi there ets .....ive just bought a 27/69 gearkit by newfren And wondered if the DRT cogs would fit ? ? Hopefully i wont need to swap about ...but would be interesting to know Thanks nik

[ets]

Nik,
I went to check on DRT website and they should all fit:
z25
z26
z28
z29

www.uvageneration.com/primarie.htm

[225worb]

Thanks for that....I had looked at DRT but thought i would have to buy there clutch drive tooo ......thanks again

[gp200]

is 22/69 a set (3.13) i have 2 sets they came with the zeta engine i got,can not see them any were,or are they just odd gears ?

[vinrouge]

Seems to be several references on the internet, being primaries gears for some of the earlier scooters

here the first that came up

www.scooterhelp.com/scooters/ACMA.125.51_52.html

[ets]

Aug 12, 2009 17:50:49 GMT @gp200 said:

is 22/69 a set (3.13) i have 2 sets they came with the zeta engine i got,can not see them any were,or are they just odd gears ?

Never heard of them before but I cannot deny their existence for smallframe engines.
The above list represent the pimaries I know for sure are (or were) available.

The vespa Vinrouge linked is obviously a wideframe and its primary wouldnt fit a smallie.
It would be interesting to see a picture of this two 22/69 to place them either in the list or back in a wideframe engine ;D

[vinrouge]

There you go, another one of lifes little mysteries revealed.

If there lardy's consign them to the back of the highest shelf of the garage or stick em on ebay ;D

[foticchio]

hello guys i have just opened a pk small engine that should be a ph 50ss i was lookin at the gears the smal one has 43 dents and the biggest one has 57 is this the standard gearing for the 5occ
how may dents should be if ti was a 125 cc 4 gear

[ets]

I've updated the list with
19/67 3.52 HC NC St - Piaggio with DRT Drive Cog


DRT produced a 19 teeth drive cog to be fitted with the standard 67t clutch basket.
www.drtdenis.com/catalogo/sottocat.htm%20DBE?idcat=68

[Jumbo-LBCSC]

So how's this 2.42 ratio (24/58 2,42 SC NC AL - Polini)
with a Polini kit, a 24mm carb and a snail pipe in a Primavera???
Will the bottom & top end be ok???
will it be nice and usable?
Thanks,

[firej]

it works ok but not as good as a 2.56 or 2.54 really depends on the rider weight....

[Jumbo-LBCSC]

So how's this 2.42 ratio (24/58 2,42 SC NC AL - Polini)
with a Polini kit, a 24mm carb and a snail pipe in a Primavera???
Will the bottom & top end be ok???
will it be nice and usable?
Thanks,
I forgot... I cut/polished the crank as well....I rode it yesterday...It flys! Long 3rd and 4th pulls as well!

[littlers5]

Any gearing ideas for a PK136 Pinasco?

Thanks
Simon.

[ets]

Depends on your configuration but generally I would say to stick to the standard 24/61

[mdwysc]

Hi all,

Im new to here so a big hi to everyone.

I am building a small frame engine for a friend of mine, she has been well and trully done up and was sold a massive pup. Long story short we have cobbled together and engine, an old 50N 3 speed.
DR110 kit
Electronic ignition
Good new mazz crank
19mm Primmy carb
standard pipe

big question, gearing. I have a Polini 24/58 set up but that seems a bit high giving 55mph @ 6000rpm. I am going to slightly bottom end tune the engine and blueprint it. does anyone know what sort of HP this will produce and will it pull the gearing we have (she isn't a big girl about 9st I would think, hope Im not wrong and she reads this lol!). If not can anyone recomend another ratio set?

Im a Lambretta man normally but am getting into this little Vespa, its quite cool.

Thank you for any help.

Markus

[breezer]

That's a 2.42 primary gear ratio which is really only suitable for REALLY high powered engines.

I reckon on that engine you probably want v90 or primmy gearing 2.86 (22/63) or 2.54 (24/61) or the polini 2.60 (23/60)

A 4 speed box would help massively.

'Ave a butchers 'ere

www.beedspeed.com/html-pages/GearRatios.pdf

[Juan]

24/72

[breezer]

I know you've had a few of these Juan but should a 110 have a lower gear ratio than a 90?

[Juan]

Yup, a 90 has miles more torque than any short stroke kit.