Scooterotica

the process of putting the gearbox is not technically difficult, but it is extremely labourious, had the endplate on and off over 2 dozen times to check the shimming but the result is outstanding, especially when you go back to riding a 4 speed. my otherwise standard TV175 performed brilliantly on a tour of the alps, and it states quite clearly that anything more than low 20`s bhp is too much, is it any wonder things are looking grim, would love to know what the ratio of failures to happy customers is?

probably too many for the price

I have one on an RB and my riding style and gear changes can be best described as agricultural. The 5 speed has really made a difference to the scooter, it's quicker through the gears, in the power all the time, has a better top end and has reduced fuel costs. It's never broken and like the prev post the gear doesn't quite line up.

It's without doubt the best after market part I have brought even at £800.

As an aside you can drill large holes in the end plate so you can see exactly how the gears are seated without the need to stick a phone down the side......

I know not a lot about lambretta so am prepared to be laughed at and shot down with my next question.
Why are you trying to fit five gears into a space made for four gears?
( I know the extra gear will be for cruising and give a getter spread of power).
I have seen engine case packers from MB to be used with a 6 plate clutch.
If the crankcase side can be packed out 10 mm can the endplate that holds the gears not be packed out by 10 mm. Then a longer set of gears could be produced that are thicker and line up better.
Just as thought.

Robbie

Along with a longer layshaft and a front sprocket carrier.Interestingly Vega's have a stepped endplate to fit 4 gears compared to a Lui 50's flat endplate with 3 speed.

You'd probably run into problems with the length of the layshaft, needing a custom one and the 'throw' on the wishbone of the gear changer. Then there's the alignment of the sprockets to consider too...

Too much

can it be done without other changes cus selector dont got 10mm extra travel the gear pivot wishbone on top of engine and tie rod wont allow it,

muppet

Ok
Yes probably too much work.
My thought was if they are making a new gearbox why not make a new lay shaft as well.
And slightly longer front sprocket.
But i suppose its going to be too expensive.

Good job im not a scooter engineer.

I suppose its just a question of fit the gearbox, shim it, check it and hopefully it will be fine.

Robbie

It's the seemingly random nature of the failures that are a worry. A lot seem to be at low speed on moderately powered scoots. On the other hand, a mate has one fitted to a tuned RB that he thrashes the life out of at every opportunity and that seems fine.

I have to agree with Bristolmods thinking.

My TS1is quick enough for me and I chose that spec because of its performance and reliability.
Although there continue to be some positive new products for Lambretta and Vespas, we don't all want or need them.
5 speed gearboxes for the Lambretta are nothing new but technically it is difficult to fit a pint into a half pint glass.

All joking aside, and I confess to not being an expert, but why couldn't a Lambretta be modified to run with a belt driven auto gearbox like many of our rev and go cousins?
Simple to make, proven to be capable of handling more power than a Lambretta could ever have?

Shoot my idea down if you like, just a idea for discussion.

Cheers