G80 Dynamo sprocket

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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Rob Harknett
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Re: G80 Dynamo sprocket

Post by Rob Harknett »

GOLDSTAR wrote:just to be different, the two I have, only have two slots, so there! kind regards

don't matter much so long as you can use the locking washer!
Snap, same as me, and as I only have prewar bikes that have a manual AR lever. That same sprocket is listed for dynamo and mag, but no key or lock washer used when fitted to the mag. both 17T
56G80S
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Re: G80 Dynamo sprocket

Post by 56G80S »

I used to use the special nut and lock washer but following advice from Tony Cooper now only use a standard nut and Loctite.

This has been fine for many thousands of miles. The standard arrangement is awkward and always seemed a but Heath Robinson to me.

Perhaps when I put it back on (hopefully this week-end) I'll do both!

Johnny B
Phil H
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Re: G80 Dynamo sprocket

Post by Phil H »

Hi Guys,
no luck at the Classic bike show today.
Any one point me in the right direction ?

Phil
56G80S
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Re: G80 Dynamo sprocket

Post by 56G80S »

I'd be surprised if Steve Survey at AMC classicspares doesn't have some secondhand ones.

Johnny B
Last edited by 56G80S on Wed Feb 10, 2016 9:56 pm, edited 1 time in total.
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GOLDSTAR
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Re: G80 Dynamo sprocket

Post by GOLDSTAR »

just happened to be looking for something else and came across my sprockets, two for dynamos but noticed one of them has a deeper shank i.e 'tis a bit longer any ideas? kind regards
Phil H
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Re: G80 Dynamo sprocket

Post by Phil H »

Hi chaps,
I have just received a dynamo sprocket from Vintage Spares on ebay & I am not Shure that its a dynamo sprocket.
It has two slots for the lock washer & a keyway, but it sticks out too far from the chain case to line up with the engine sprocket.
is the one I have a Mag sprocket it is 21 mm in depth ?
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dave16mct
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Re: G80 Dynamo sprocket

Post by dave16mct »

Move the dynamo over until it lines up.
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clive
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Re: G80 Dynamo sprocket

Post by clive »

Phil H wrote:Hi chaps,
I have just received a dynamo sprocket from Vintage Spares on ebay & I am not Shure that its a dynamo sprocket.
It has two slots for the lock washer & a keyway, but it sticks out too far from the chain case to line up with the engine sprocket.
is the one I have a Mag sprocket it is 21 mm in depth ?
If it has the slots and keyway its not a mag sprocket. One possibility is that the size of the sprockets changed when the longer E3N dynamo was introduced. Tried looking at parts lists but cannot confirm this. What gearbox do you have, the earlier CP box will not work with the later longer dynamo?
clive
if it ain't broke don't fix
56G80S
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Re: G80 Dynamo sprocket

Post by 56G80S »

What's the model and year, Clive's post hints at this although it's no guarantee that the machine is still "original" after all these years.

Speak to the club AMOC Spares or AMC Classic Spares as they know what they're talking about and save money against purchasing online from those who may not.

Dave16mct's remark should hit the spot but do invest in the dynamo locating strip which screws to the dynamo and fits between the engine plates to prevent the dynamo from across the machine. I've experienced dynamo chain and primary chain clashing and it's not good.

Johnny B
Phil H
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Location: UK

Re: G80 Dynamo sprocket

Post by Phil H »

Thanks for this advice.
The bike is a 56 G80 cs I think it has never been a road bike, I had to take the blanking plate off for the chain case the to fit dynamo.
I can't move the dynamo further back because it comes up against the gear box & then there is quite a gap between the end of the dynamo & the chain case.
Do I need the shorter dynamo or a deferent sprocket ?
Locked