Dynamo Chain

[AngleseyAJS]

Good morning,

My 1955 AJS 18S is in need of a new dynamo chain.
Ive never really had the need to count the links on a chain before so have found this to be a head scratcher!
From looking through the forum I get the impression that it's every link to be counted. I get it to be 49 links.

Screenshot_20231031_113103_com.google.android.apps.photos-01.jpeg

My chain is endless and seems to have a half link. Is this normal?

Screenshot_20231031_113113_com.google.android.apps.photos.jpg

I should add that I'm not 100% sure that this is the correct chain as someone in the past has changed the dynamo to a different model. I've now bought the correct dynamo so really want to be sure I order the right chain.
I've looked in the archives but can't see to see the info on chains

Thank you all in advance

[SPRIDDLER]

My 1955 AJS 18S is in need of a new dynamo chain.
I've looked in the archives but can't see to see the info on chains

It's important that the chain is endless, having 49 links and that the sprocket is secured with the correct nut, locking washer and circlip.
See page 19 in the factory spares list for your bike here:

http://archives.jampot.dk/book/Spares_l ... ingles.pdf

These are the correct sprocket securing bits..

2018-01-24 Dynamo nut, washer, circlip 001.JPG

[AngleseyAJS]

My 1955 AJS 18S is in need of a new dynamo chain.
I've looked in the archives but can't see to see the info on chains

It's important that the chain is endless, having 49 links and that the sprocket is secured with the correct nut, locking washer and circlip.
See page 19 in the factory spares list for your bike here:

http://archives.jampot.dk/book/Spares_l ... ingles.pdf

These are the correct sprocket securing bits..

2018-01-24 Dynamo nut, washer, circlip 001.JPG

Mmm thank you Spriddler, I don't have a picture to hand and the bike is at my dad's garage but Im 100% certain there wasn't a locking washer or circlip on it.

Someone had fitted a Lucas E3AR which I'd spotted wasn't right and when I found it didn't work I thought I would rather put my money into getting a correct E3N.
I'll fire up the PC and have a look at the link.

Do you think it should be the 49 link chain?

Many thanks Spriddler

[SPRIDDLER]

Do you think it should be the 49 link chain?

With the correct dynamo and sprocket the chain will be as shown on page 19 of the spares list to which I've linked in my previous reply.

If you're unable to open the link, this is what is on page 19 in the spares list.

Chains 55 single.JPG

[SPRIDDLER]

I'll add this tip in a new post as it's very important...........

When you fit the dynamo make absolutely sure that it is positioned laterally so that the dynamo chain cannot clash with the primary chain. If it does it's most likely to break, causing serious damage.
The dynamo *should* have an alignment plate bolted on top of it so that if you need to adjust the dynamo chain in future you can ensure its correct positioning without having to remove the outer chaincase. The alignment plates are often missing so when you've aligned it make a mark with a felt tip pen or whatever on the dynamo body.
(Incidentally I'm pretty sure that the E3AR dynamo that you have will fit and work fine if overhauled (I'm sure I've previously used both types on the same bike) but the E3N will have a slightly higher output).

Dynamo alignment plate 2.jpg

[AngleseyAJS]

I'll add this tip in a new post as it's very important...........

When you fit the dynamo make absolutely sure that it is positioned laterally so that the dynamo chain cannot clash with the primary chain. If it does it's most likely to break, causing serious damage.
The dynamo *should* have an alignment plate bolted on top of it so that if you need to adjust the dynamo chain in future you can ensure its correct positioning without having to remove the outer chaincase. The alignment plates are often missing so when you've aligned it make a mark with a felt tip pen or whatever on the dynamo body.
(Incidentally I'm pretty sure that the E3AR dynamo that you have will fit and work fine if overhauled (I'm sure I've previously used both types on the same bike) but the E3N will have a slightly higher output).

Dynamo alignment plate 2.jpg

Thank you for the reply Spriddler.

I've opened it up on my PC and it certainly does look to be the 49 link chain, I've counted the teeth on the dynamo sprocket and they match the one being sold so i'm happy to order that one.

The E3AR dynamo wasn't working, after chatting with the guy who was going to repair it we decided it was better to go back to an E3N and a deal was struck.

The alignment plate seems like a great idea, unfortunately mine hasn't got one on so i with just have to measure twice and cut once!

Thank you for the advice , much appreciated

[dave16mct]

You can buy an alignment plate or make one. There's a drawing in Christian's archives:
http://archives.jampot.dk/technical/Do- ... guess).pdf
Dave.

[AngleseyAJS]

You can buy an alignment plate or make one. There's a drawing in Christian's archives:
http://archives.jampot.dk/technical/Do- ... guess).pdf
Dave.

Cheers Dave, i'll have a look at that

[Groily]

Would need to drill and tap dyn body for the bit o' bent tin if not already done though.
Good move to have gone for the E3N. The ARs were only fitted to 1950, and are inferior jobbies for a variety of reasons relating to output, durability of construction, and maintenance.

[AngleseyAJS]

Would need to drill and tap dyn body for the bit o' bent tin if not already done though.
Good move to have gone for the E3N. The ARs were only fitted to 1950, and are inferior jobbies for a variety of reasons relating to output, durability of construction, and maintenance.

I like to live life on the edge but drilling and tapping a newly acquired dynamo body might be a step too far!!

I can't remember any holes but I'll check