Primary shock absorber spring

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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Re: Primary shock absorber spring

Postby clive » Mon Sep 17, 2018 7:04 am

Spriddlers advice is still good as for any road speed with the new sprocket your engine will running slower. This will reduce the dynamo output. So If you expect to do a lot of night driving or want to use daytime lights fit an LED headlight or daytime running light.
clive
if it ain't broke don't fix

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Re: Primary shock absorber spring

Postby adz25 » Mon Sep 17, 2018 10:43 am

Thanks for the advice gents, it will be more of a weekend ride so not planning on needing the lights too often.

I will look at getting a smaller chain for her and use this primary sprocket.

Many thanks

Adam

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Re: Primary shock absorber spring

Postby clive » Mon Sep 17, 2018 5:05 pm

Bit confused the dynamo sprockets are the same size and the primary drive sprocket is larger. Means you will need the same dynamo chain and a larger primary chain.
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Re: Primary shock absorber spring

Postby adz25 » Mon Sep 17, 2018 5:16 pm

Clive,

It is a little confusing, but basically I had a 19 tooth primary with a 21 tooth dynamo attached (in the box that came with the basket case) and the chain I bought for the dynamo for my year fitted perfectly as did the primary chain.

The new sprocket is 21 tooth primary but only 17 tooth dynamo. So the dynamo chain I have is at least 2 links too long and is endless.

So to run this sprocket I need a shorter dynamo chain as the adjustment on the dynamo is not enough to take up the slack.

The primary chain is long enough to account for the 2 extra primary teeth.

Hope this makes sense, it's turning into a bit of a mission for me, unfortunately it's my fault for buying another basket case!!

Many thanks

Adam

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Re: Primary shock absorber spring

Postby raffles » Mon Sep 17, 2018 5:42 pm

If your chain is to long and in good nick just take out two rollers and re rivet it. As you are in cambridge I am sure one of those nice
Fennruner chaps will help out if you dont have a rivet extactor or you could buy one from the club
Tony

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Re: Primary shock absorber spring

Postby adz25 » Mon Sep 17, 2018 6:37 pm

That's another thought to consider!

Many thanks for all your assistance

Adam

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Re: Primary shock absorber spring

Postby clive » Mon Sep 17, 2018 6:48 pm

adz25 wrote:Having just double checked they are both 17 teeth.
Many thanks
Adam

This is what lead to my confusion!
clive
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Re: Primary shock absorber spring

Postby adz25 » Tue Sep 18, 2018 5:54 am

Ah I see Clive, I was referring to the new primary sprocket(dynamo teeth) and the actual dynamo sprocket.

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Re: Primary shock absorber spring

Postby 56G80S » Tue Sep 18, 2018 8:08 pm

Back on the spring, mine is square section and has been on for a very long time after a round section spring failed and didn't want to make that mistake again.

Johnny B

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