Author Topic: 1955 A10 swingarm model - headlight bolts - what and where to order please?  (Read 530 times)

Offline BrianS

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I have already accumulated a stash of nuts and bolts that I have wrongly bought because of my ignorance of non-metric threads and don't want to add to the stash!

My A10 headlight unit is currently held in place with nuts and bolts. However, there are captive nuts on the inside of the headlight with good threads so I would like to secure the headlight unit with just bolts.

I have ransacked all my boxes and found one bolt which fits the captive nuts.

I have a non-metric thread gauge and reckon the threads on it are 20tpi.  The diameter of the bolt is .426". I am guessing this is close enough to make it 7/16"?

An 11/16 A/F socket fits the hex head quite well.

What I need is a pair of chromed bolts preferably with the same "thin" hex head and about an inch long.

Can anyone help me by saying exactly what I need to order and, preferably, a supplier please?

The "correct" bolts on Draganfly don't look right - see   https://www.draganfly.co.uk/index.php/triumph-shop/1937-1949/twin-cylinder/product/26727-headlamp-bolt

Photos of the "nearly correct" bolt below.

Brian


1955 BSA A10 Golden Flash
Exeter, Devon, UK

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I got the Draganfly ones. If you have a look for my recent post with pictures of my headlamp arrangement you will probably be able to see the bolts, (screws actually).

Offline BrianS

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Thanks for the quick reply!

I confess that I had forgotten I had already asked the question on an older thread  *sad2*

The Draganfly site doesn't say what size their "Headlamp bolt 112201" is. Would it be the 7/16" 20 tpi thread that I need?

I think the standard A10 headlight unit takes 5/16" which is too small to fit mine.

Brian
1955 BSA A10 Golden Flash
Exeter, Devon, UK

Offline duTch

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 Seems possible that someone has drilled out out  for a quick/easy fix to use 7/16 UNFBSC
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline JulianS

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Later headlights, certainly Triumph fitments, used a 7/16 x 20 tpi UNF bolt.

This could be what you need?

http://www.ebay.co.uk/itm/Lucas-headlamp-bolt-LU541044500-one-pair-7-16-/281643838123?hash=item419347eaab:g:gWEAAOSwv0tVFZHj

Offline BrianS

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Thanks for the replies chaps  *smile*

Looks like the Triumph bolt is the way to go!

Not sure what the finish is on the eBay SRM bolts - they look a little dull if chromed but I have sent them a message asking the question. The nuts look slightly domed which is good.

Having got the lead on what to look for I found these 22-0013 which look really nice but are twice the price!  https://www.triumph-spares.co.uk/cat_details.php?p_head=Headlamp

Brian
1955 BSA A10 Golden Flash
Exeter, Devon, UK

Offline BrianS

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Just a thought. I am hoping to go to my very first m/c autojumble - the "Vintage Motorcycle Club Autojumble" at Shepton Mallet - on 12th August.

Are there likely to be stalls selling things like headlight bolts so that I can see (and check) what is on offer before buying?

Brian
1955 BSA A10 Golden Flash
Exeter, Devon, UK

Offline a101960

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You should have no problem finding what you want. If you are unsuccesful, which I very much doubt you can get them in stainless from Barleycorn Engineering. They will be with you in a couple of days or less. Thats where I got mine from. http://www.barleycorn.co.uk/BSA-Goldstar?page=4

Offline JulianS

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Barleycorn usually at Shepton Mallet

Offline BrianS

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Not sure what the finish is on the eBay SRM bolts - they look a little dull if chromed but I have sent them a message asking the question.

SRM confirmed that the bolts are 20 tpi but unfortunately they are only zinc plated and not chromed  *sad2*
1955 BSA A10 Golden Flash
Exeter, Devon, UK

Offline BrianS

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Being impatient to get the A10 back together again, I tracked down the bolts I needed from L. P. Williams of Claughton Part number 22-0013 "Domed chrome headlamp bolt 7/16 UNF 20 tpi"

So I can get the headlight back in and actually start to ride Flash again  *smile*

Well, not in this foul weather  *sad2*

1955 BSA A10 Golden Flash
Exeter, Devon, UK