Scooterotica

Thanks for your comments guys

Fair enough about oil if you want to use it use it. Most motorbike boxes are different because they don't run constant mesh like Lammys do. They need a nice film of oil between the gears.

Diablo wrote:Fair enough about oil if you want to use it use it. Most motorbike boxes are different because they don't run constant mesh like Lammys do. They need a nice film of oil between the gears.

+1

imo the gears are submersed in oil permantly even if it is at the bottom section of gear cogs and in being immersed like that seem to get plenty of lubrication epesh as there is more of each gear cog unmeshed than meshed to xmas tree at any time .
what is great about this hobby is there are so many different options for something as simple as oil or clutches and im always willing to listen and try something thats a bit different normally to my expense admittedly
if i have any questions i will hunt out the experts in the area of what i want to try to understand and ask questions i even sometimes listen to the answers

Diablo wrote:Ok 5 plate clutches.
They work its just that few people set them up properly and give the springs too much work to do.
Before you go shelling out on a 6 plate clutch you probably don't need, check the clearance between the top plate and the first cork with the clutch fully compressed with your clutch compressor.

You want no more than 1.5mm free play here. Anymore and the springs have to extend too far before they start to put pressure on the plates.

You may well find you have anything up to 4mm of play which is a lot to take up. You can do some of this by using only thick clutch steels and also a thicker top plate. If this doesn't get you closer to the required gap you can mix your green surflex plates with surflex b corks which are thicker. I've used 2 of the "b" corks and 3 green ones to get it right.

The AF uprated springs are good and very cheap although not as good as the ones they had in the surflex cassette clutch.

With regards light gear oil next time you build your gearbox ask your self what stops the cogs rubbing together? Use at your peril.

wish you had posted this a day earlier as i had just stripped mine down and built without springs and found exactly what you stated.

one thing i found was as i have a crown wheel that has been altered between the turrets there is room to fit 6 thin corks but not enough for the extra plate.
there seems to be enough room for the pressure plate to drop further but the legs foul on the inner.
would it be possible to file the inner to allow for this and then run a six plate. or are there steels available that are less than 1.5mm.
in the end i got some longer springs from Ron Moss, checked they didnt go coilbound and put it back with 5 thin corks.
i deliberated long and hard but bottled the thought of mixing corks. wish i had now.

test ride today will confirm, if i can get some fuel.

Just an update.
Springs fitted from Ron Moss, they're longer with same number of coils.
Machined flat on the ends and clicked nicely into the spider.
Replaced cable inner and outer lever is firm but not excessively hard.
No slip with 5 green corks.

I have quite a bit of experience with RS125 clutches and gearboxes. The RS125 does run a constant mesh sequential box in an oil bath with the clutch but ask yourself one very simple question? How many RS125 gearboxes and clutches are around after 5 years? Then ask yourself how many lambretta gearboxes are around after 20, 30 even 40 years!

Functionally a standard multigrade will do the trick but you will not get the service life out of the parts that is the difference. If your gear box is old, substandard, poor quality then expect it to wear out that much quicker (if you use multigrade oil) and critical bits break because the oil is thinner and has not protected the surfaces under pressure.

RS125 engines are a bit of a delicate flower, they require very regular servicing, bearing, balance gear, friction plate and oil changes.

Critical with Lambretta clutches is getting a matches set of springs. To dip into a box of parts and get 5 springs the same length is simply not good enough. Critical in Lambretta clutches is that the pressure plate engages and dis-engages squarely not on the p*ss. Anything less than a new set of identical springs would be a waste of time. Working out the preload and spring weights is a simple bit of maths.

^
so would using a drilled christmas tree and an sx/Li pressure plate withe the nipple taken off be a step in the right direction.

Jazzy wrote:^
so would using a drilled christmas tree and an sx/Li pressure plate withe the nipple taken off be a step in the right direction.

But that's just cheating,

muppet,

Is there another way to contact Rocho other than pm?