Scooterotica

when you say 'current boxes' do you mean one you manufacture or just the ones available from dealers etc?

The ones available from dealers, Indian, Spanish and Italian.

http://lambretta.co.uk/catalog/product_ ... ts_id=6303

:shocking:

Hi all
just never got round to cutting a g/box out of en36,
the one we did do out of en24 was a bit soft,but was a good allround box,
and at a cost of about £500 who wud want one,

Here is the problem, about 95% of Lambretta engines do not make 20BHP and would never be close to breaking the current gearbox. Of the remaining 5% people want different ratios, different budgets or both. To produce a single piece lay gear requires that at least one gear hobbing tool has to be "Topped" to make a short tooth (look on original lay shafts and you'll see what I mean, the root of second gear has to be outside the OD of first). Hobbing tools are very expensive new so gear cutters are highly reluctant to scrap a good tool to make a Lambretta gearbox. Also, the machining of a first gear with kick start teeth on it is expensive and finally (once you have resolved all of the above) you end up with a tooth width that is only marginally stronger than the original.

There are ways around it but they all add cost, time, manufacturing processes and essentially at the end of the day the majority of people will then compare it to an original gearbox. One other additional point is that as bolt on kits get better and people realise the importance or torque spread, the requirement for a particular type of gearbox (pacemaker for example) will deminish as pretty much any gearbox with the right primary drive will do the job.

I worked out that making 30 gearboxes with wider and thicker teeth on a two part laygear (fixed 1st and 2nd on a splined shaft with a removable 3rd and 4th) would come in around £550. But that means selling 30 gear boxes from the get go! When you consider the investment to do this and the current set of economics that are likely to decend on us in the next 6-12 months you'd have to ask yourself, "why take this substantial risk?" particularly as there are others who could pop up with a competitive product and wreck the commercial model.

OK, interesting stuff......so forget the removable 3rd/4th option......if people just wanted a close ratio 4 speed box made from decent material that could cope with 30-40bhp.....how much would that cost?

i was wondering that as well

I wouldn't made a single piece lay shaft as a hobbing tool is circa 700 quid. A one off gearbox would be around £1K plus the tooling so no change out of 1.7k

as i said in my last post £500,
we have cut 2 number gearbox and gears so far,
and no probs with first gear on the kick start,
just talk to mph,man he will tell u,
stu owen

M.B Developments had a couple of 5 speed gear boxes made, one is in Marks lambretta which is 30+ hp and has been reliable. They cost him over £1000.00 each, Rich T's cost is quite realistic on a gear box that will be reliable enough for high powered engines.