Can any one confirm the correct length for this bolt

I have some “new made” bolts which are longer than what I had always considered to be original bolts i had for some time
Were there 2 different lengths - perhaps wartime and later post war set ups
I cannot provide lengths just yet as am wrong side if Irish Sea until Wednesday
Anyone ?
Jo’b

email (option): jonnyob1@googlemail.com

Hi John
You're not referring to the fact that one bolt is longer to accommodate the chain adjuster are you? I think I've got some NOS ones I could measure if no one else chips in quickly here.
Bob

Sorry John
For misunderstanding your post.
Looking up the part I now see what you mean. I've got these bolts in different lengths too, but can't help with their use. They were given me by a BSA bloke who didn't know either.

is it not 66-7523?

I also have found these in varying lengths :thinking_face:

Could be something to do with the later swinging arm alloy chain cases, these could be the long ones.

Tim W

Drags list 66-7523 as sliding plate short. Presumably then there is a different part number in the post war lists for a longer bolt.

https://draganfly.co.uk/shop/74308/sliding-plate-bolt-short/#66-7523

Ron

email (option): ronpier@talk21.com

The thickness of the sealing felt can also have an effect...Some pattern felts are too thick. When the nut at the rear is fully tightened the shoulder on the bolt sits against the rear face of the chain case.. The shoulder must be of a length whereby the plate and the felt are compressed to make the seal but are not so tightly held that they will not slide readily when the gearbox is moved to adjust primary chain tension...

I generally assemble everything and test the condition outlined above..If the bolts are too short you can fit shim washers under them to give more length...If they are too long you can try a washer under the head to take up the clearance...As I have a lathe I generally make mine to suit each time I build a bike, once I've worked out what's needed...

On my Gold Star I replaced the felt seal with a neoprene ring which I greased on assembly and that works well and gives a more consistent thickness across its surface and good support for the sliding plate....Ian

email (option): ian@wright52.plus.com

Thanks all
Ron
I looked at that bolt/screw it looks like the long ones I got myself
The shorter version is noticeably shorter
I’ll compare them tomorrow as in the U.K. again & in the sheds packing next 2 days
Br
Jo’b

email (option): jonnyob1@googlemail.com

I was reminded about this bolt this morning.

Does this look about correct?



Mark

email (option): pes.sales@btconnect.com