1930s bike frame developments!!

Dillo27

Dirt Disciple
Hello folks...

This is an update on the Old Beast posting,

I've narrowed down the likely identity with as reasonable certainty as possible. I believe it's a Sun of Birmingham probably made in the mid to late 30s. and am having it refurbished accordingly.

Also I've managed to get hold of the correct period type of headset, the clip and bolt top part plus three shims, but no top nut and no bearings.
I reckon I can use a standard top nut but
does anyone know what size bearings I should use?
Looks quite a small gap for them.

Pics to follow of refurb.
 
Re:

Standard headclips used 1/8 in balls, some had a larger size on the crown race. Your top and bottom cast lug should have an inserted loose bearing ring, the sort used by millions of cheaper roadster bikes.
Most headclips used a 31/32 diameter top thread from memory 56 tpi. A few mostly later head clips had a standard 1 inch by 24 tpi top nut.
A few raleigh headclips were 1 inch x 26 tpi.

Keith
 
Re:

The vast majority of roadster type bikes from about mid 30s had fork column 1 inch x 24 TPI, Raleigh 26 tpi. Head clips were used mainly with cast lugs which were superceded by pressed / welded lugs.
Most head clip types were 31/32 inch diameter at the top of the fork column (correct term at the time).
Keith.
 
Re:

Thanks for the info guys, very informative,

The frameset is back from the paintshop but now I find the headclip and shims are not a match!!

I think it's a roadster style set I'm needing so back to the search...
 
The case hardened loose bearing rings were used on millions of cheap bikes. Typically the vast majority of post war BSA bikes used this cheap system, with a threaded top race not head clip. We used to sell these 2d each (2 old pence). Either find a scrap bike or get some made.

Keith
 
Re:

Yes, I'm in the midst of acquiring a doner bike which looks to have an identical set up.
Just waiting on the courier!
 
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