Is the 1957 ES2 negative or positive earth?

Is the 1957 ES2 negative or positive earth?

Almost certainly positive earth with a Lucas E3L dynamo. Of course you can always alter the dynamo to negative earth, as has been done to my wife's A10. Must change it back one day...

My '57 model 77 is positive earth (confirmed by lucas schematic). I was recently told:

"British bikes only went positive earth when alternators started
appearing in the early 50s.

Nortons went positive earth around 1954, everything before that was negative
earth.
Since there are no semiconductors involved without an alternator (and
diodes), doesn't actually make any difference - as long as everything is
in agreement."

Hope this helps

Skip

Previously wrote:

My '57 model 77 is positive earth (confirmed by lucas schematic). I was recently told:

"British bikes only went positive earth when alternators started
appearing in the early 50s.

Nortons went positive earth around 1954, everything before that was negative
earth.
Since there are no semiconductors involved without an alternator (and
diodes), doesn't actually make any difference - as long as everything is
in agreement."

Hope this helps

Skip

Good comments above. Hopefully here a few more. yes the bike almost surely should be Positive earth. You can change it to negative earth if you like BUT bear in mind-Dynamos can be polarised either way round. Mechanical regulators 'don't give a dam' but electronic regulators do. Ie the modern electronic regulators (me and few others sell) pin you down to what ever polarity you buy.

IF the bike was Positive from the factory then it is advisable to retain this certainly the next owner would appreciate it! Wiring colours. A Positive earth bike should have a RED earth wire, if you connect it up negative earth you then have wrong colours on your battery wiring-at your peril!

Alternators-'don't give a dam' either. The older (black) rectifiers were made with a polarity mostly positive earth but negative was available. Similarly with Zeners, mostly made Positive but Negative is available. Modern encapsulated rectifiers (four terminals) as with modern regulator/rectifiers are very concerned in themselves but they can be connected either way on the machine.

2MC caps, LEDs, Electronic ignitions and electronic regulators are all polarity conscious. So take good care when connecting. I think we have strayed off the point! Ho Hum.

Al Osborn.