Top pivot 18648 - How long is it ?

[JEAN-NOEL]

Hello Gents,
Everyday a new problem !
I think my bolts top pivots were shortened, as they are not long enough to catch properly the rear mudguard with the grabrails.
My bike is an export CSR (64/65) so it has no bridge and alloy mudgard, but a chrome plated one, looking like 650 Manxman or Atlas.
I think that the suitable bolt is similar to 650 STD, ie 18648.
I have got superb SS Top bolts with polished radiused heads, 3" 3/4 but they seem to be a bit too long.
2 Questions :
1°/ What is the lenght of the 18648 Top pivot ?
2°/ According Girling catalogue, the max stroke of the suspension unit is 3,1 ". Do you think there is a risk of rubbing the tyre (3.50/18) if the bolts are about 1/2" too long ?
As always your advices will be welcome !
Kind regards. J.N.

[Rob Harknett]

http://archives.jampot.dk/book/Spares_l ... ements.pdf
I guess you mean 018648 Jean-Noel the size is 3 1/8" x 3/8" 26 TPI
It took just a few seconds to discover that size without even leaving my computer.
I have said many times here on the forum, how to discover many sizes of fittings. So if you are reading this pass the knowledge on.
Old parts lists stated many sizes of parts, not just nuts and bolts. Approx 1952 parts lists changed to new part numbers. The parts lists then stopped giving many part sizes. Old parts still in use from pre 1952 were all given new part numbers. So in many cases you need to refer to a Master parts list, to covert a number from new to old. To assist members in discovering sizes for them self.

I recently made a huge approx. 50 MB file to do this. The file contains a list showing the conversion of old to new & new to old. So easier to use depending if you want to look for a new or old part number. All numbers are listed in numerical and alphabetical order. The file is in 3 sections, first 1954 master parts list, followed by 1955 & 56 updates. So you may have to search all 3 sections, although you will find most parts sizes in the 54 section. The file also covers Burman, Amal and cables ( with cable lengths )
I have written the title of the file so it appears right at the top of Books / Parts lists section in the archives. See link above.
I will not be archiving any more content of my library of literature in the archives, which now has a new host. Unless I update my system and buy new software.

[JimFitz]

Thanks Rob. A really useful list and a "must have" when working on our machines. Now downloaded to my PC for future reference.

Jim

[JEAN-NOEL]

Hello Rob,
what a good job you have done !
Now downloaded to my P.C.
Thank you very much.
Kind regards. J.N.

[Rob Harknett]

Jean- Noel Could you not shorten your 3 3/4" bolts to 3 1/8" being stainless the cut ends will not rust.
The file is also good if you have a pre 1952 bike, so you can convert and old pt. no. to a new pt. no. You need the new part number to search and order via club spares. It also gives you two options to look for old stock parts, via the new and old number. Owners of pre 1952 bikes will discover the club has many parts for their bikes, but they must use new pt. no's to find them. Some parts will fit bikes back to as early as late 1920's ( mainly STD fittings which old part numbers start e.g. STD1 = 000001. You just drop STD and prefix the number with as many zero's needed, to make it a 6 digit number e.g. STD 999 = 000999.

[JEAN-NOEL]

Hello Rob,
You are right : I have to thread the bolts a bit, to fit the rear mudgard and then, to shorten the part protruding the nut. I have now to order a 3/8" 26 TPI die + die holder from Tracy Tools (£ 6) +£ 10 postage !
Thanks for your help. J.N.