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Modern Synthetic Oil In Bsa Bantam Gearbox

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Most people use a mineral 20/50 in the gearbox casing. Has anybody tried a modern synthetic or semi-synthetic bike oil suitable for wet clutches . I am particularly concerned about the effect on the cork friction rings between the steel plates.

What quantities are people using. Have heard anything from .5 to a full pint.

Any comments.

Most people use a mineral 20/50 in the gearbox casing. Has anybody tried a modern synthetic or semi-synthetic bike oil suitable for wet clutches .
Yikes. It was a monumental task getting pre-65 classic bike riders to consider multi-grade oils in the first place! Now you're really playing with fire! :guinness:

Doug

I've used semi synthetic in the clutch of my C15 with no problem. Full synthetic not good for clutches apparently. C15 has a seperate clutch and gearbox so not bothered what goes in the gearbox as long as it's wet.

Some synthetic oils use friction modifiers ( its a cheap way for the manufacturer to make the oil reach its specification ). Generally these are not suitable for the clutch- even on modern engines as they will cause slip. I use TQF- automatic transmission fluid in the clutch.

With you on that Mick. I've been using TQF fluid in the clutch since i bought my first Bultaco slimline in 1971. Currently using TQF in the B40 along with EP90 in the gearbox. Seems ok. Never had problems on any of my bikes. Change it after every 4 or 5 trials as its cheap enough.

I've always thought the thing with oils is to change it regularly as fresh oil even if a cheapo one is better than an expensive oil thats only changed rarely.

One other thing i am led to believe that a lot of engine builders do NOT recommend synthetic oils till AFTER the engine has been fully run in as they do not allow the bearing surfaces to bed in properly and using synthetic from new can actually harm an engine :guinness:

Only what i've been told by "people in the know" :guinness: Ah thats better :guinness:

Dead right, i never use synthetic until they are fully run in. And that can take quite a while on a trials bike unless its used on the road. Some new cars and light commercials use synthetic right from new but they use different tachnology to us!

said it before and i'll say it again

TESCO VALUE OIL 93P A LITRE

change it every month job done for nowt..

ouch checked today and price has gone up now

Edited by totalshell

  • Author

Cheers guys. i'll stick with the tried and tested mineral oils with the wet clutch in the gearbox and i think it has to lubricate the main brgs. as well in a bantam.

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