Ariel Owners Motorcycle Club

Hi folks,
Can anyone suggest where I may be able to get a decent fibre drive gear for a Lucas E3LM dynmo ? I bought one off an ebay supplier a couple of years ago and have found when I tried to fit it recently to my VBs dynamo that it is slightly too large and the teeth are not correctly cut, meaning that it is useless.
Thanks,
Bevan

Draganfly seem to list what I think you're looking for.

Aren't the dyno gears steel?
(All mine are steel, I don't remember ever seeing a fibre gear to fit on the dynamo - or is the problem the fibre wheel that goes in the magneto?)

SG

The 57t drive wheel on the magneto is normally fibre, with a matching 22t steel wheel on the dynamo. However, I have a steel magneto drive wheel which then needs a fibre wheel on the dynamo. Using a steel on steel drive combination could lead to noise. I believe the idea of a fibre drive wheel is that if the bike backfires whilst the dynamo is spinning, giving a sudden reversal of drive, the fibre can sheer, rather than damage the dynamo.
If the problem is a tight fit of the 57t magneto drive wheel in the magneto housing, it can be eased by careful use of a fine grade abrasive flap wheel to reduce the teeth height.
You also need to check that where the plain friction disc fits in the large fibre wheel is not worn to a larger diameter, as this can effect the eccentricity of the drive.

The earlier Monobloc Mag dynos had a large steel gear and a Keyed fibre small one on the generator armature end, The fibre gear was prone to self destructing due to a poor grip on the generator shaft. There are also some large fibre drive gears without the slipping facility about. Someone will know what they were for. Nev

Thanks for the replies. As most of you will have realised, I should have said "the fibre gear on the magneto that drives the metal gear on the E3LM dynamo".

hi i have seen the fiber wheels on EBAY , i got one off Ebay last year for a 1951 NH 350

Unfortunately, I can't recall if I got the duff fibre gear from Drags or ebay, so I'm a bit cautious about potentially wasting more money. My old one is worn but still serviceable, so I'll put it back into service for the time being.