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Headstock cover plate

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Headstock cover plate

Posted by alex_arthur at August 21. 2017

Can anyone identify the set screws (?) part no 23573 that should attach the cover plate to the headstock on my 1960 slimline frame?  None of the usual suspects appear to keep them (based on a search against the part number) and it is not listed in the 'Stainless Steel Fasteners list' that is often quoted as help for these matters.  From the measurements I have made it would appear it could be either 1BA or 7/32" CEI, but neither appear to be a preferred size, or at least they are proving very difficult to find!  A source for both the set screw and the special, curved face, washers that sit underneath them would be much appreciated.

Thanks

Re: Headstock cover plate

Posted by anthony_curzon at August 21. 2017

You could take them to Will at Classic Stainless and he will make them for you if you can provide him with a sample of the part that you want made. He has made many of the nuts, bolts and screws that I could not obtain else where in stainless steel.

Re: Headstock cover plate

Posted by robert_tuck at August 21. 2017

I think curved washers are availiable for mudguard fixings from one of our suppliers ,could be the same part?. I would have guessed cycle thread for the bolts.

Re: Headstock cover plate

Posted by alex_arthur at August 22. 2017

Thanks for the replies.  Yes, I would tend to expect CEI given the Norton usage of that thread at the time.  I have had some stuff from Stainless Classics (I assume it is the same company you refer to Andy; Will Horgan is the owner) and it has been excellent quality and a fair price. I will give him a call to discuss as I have compiled an order for him from his Featherbed list anyway. He may be able to confirm their diameter and threadform too in which case I will add it to here for future reference.

Robert, good spot on the mudguard washers. I have checked and they are the same part number (13192) as those called up for the headstock cover assembly.  Further, they are easily available from the club as well as from at least one of the normal suspects.

Re: Headstock cover plate

Posted by robert_tuck at August 22. 2017

Thats usefull as I am missing a couple of washers. I think the fixings are hex head as impossible to get a screwdriver in there?. They do sometimes snag a cable so rounded off heads would be better.If you are getting some made ,get a couple for me too.!!

Re: Headstock cover plate

Posted by alex_arthur at August 22. 2017

Received a reply from Stainless Classics - they are unable to help.  I have blown up the picture of the frame and fixings from the Andover Norton site (same picture as in all of the parts manuals) and the fixings certainly look to have a rounded head form.  The search continues...

Re: Headstock cover plate

Posted by David Cooper at August 22. 2017

Alex..I can't check mine for a couple of days but I think they are slotted cheese head. It wouldn't surprise me if they were not 'preferred size'.. manufacturers like to make sure customers go to them for small spares!

The covers aren't very often in place  (from my observations). If nobody else turns up with the size I'll try to check it next weekend.

Re: Headstock cover plate

Posted by Gordon Johnston at August 22. 2017

It's so long since I checked but I think they are 1/4" x 26 cycle thread. My cover plate is in a box somewhere...

Re: Headstock cover plate

Posted by alex_arthur at August 22. 2017

Thanks, Gordon, but I have tried a 1/4" x 26tpi and that is definitely too large a diameter.  I have managed to find probably the only 7/32 x 26tpi set screw from my collection after turning out every container I have (I knew that keeping everything was a good idea!), and that just about fits (if marginally sloppy), which possibly confirms what I had previously measured by less accurate methods.  Given that there is likely to be some wear in the threads of both my screw and the headstock, I am inclined to think that this is the correct size.  Incidentally, Will at Stainless Classic replied very quickly, but saying that he 'could not supply 7/32 BSF', but as BSF would be 28tpi at that diameter and the thread comb gives a good fit on the screw I have at 26tpi, I am not sure he is correct (unless Norton used a different thread on later frames, which is not unlikely!). I think therefore that I probably need to find a supplier of 7/32 26tpi set screws and preferably with a slotted cheese head or similar, as David suggests.  However, if you are able to confirm that this is indeed the size, David, it would be much appreciated.

Re: Headstock cover plate

Posted by Gordon Johnston at August 23. 2017

You could always take the easy way out and run a 1/4" CEI tap through the holes... Cheating, I know.

Re: Headstock cover plate

Posted by alex_arthur at August 24. 2017

Well, I have continued to draw a blank on finding any 7/32 26tpi fastener - despite using every internet search term I can think of!

Gordon's suggestion to re-tap at 1/4 26tpi is probably the most pragmatic and I will probably adopt this solution, though it goes against the grain a little.  The decision is assisted by the fact that the washers fit on a 1/4 fastener on the mudguard and a 1/4" 26tpi tap set is readily available. The bike is all coming apart anyway (it was built and used as a racer by the PO; I am returning it to as near standard as realistically achievable) so the creation of swarf will not be a problem.

Thanks everyone for all of the input, hopefully it will also assist  someone in the future too.

Re: Headstock cover plate

Posted by michael_sullivan at August 24. 2017

My parts book shows the following:

no drawing number,  pn: 22637  Headlug cover

H59  pn: 23573   Fixing screws for cover  Qty 2

pn: 13192   Washers for fixing screws Qty 2

I haven't been able to find a cross reference that tells me what the threads are.  This is just a guess but pn 23574 is shown as     nut 1/4 CEI x 26

Mike

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