PO bike headset question

[bm0p700f]

Well it an old PO bike, its old and the headset is knackered.

What year could it be, yes it has rod brakes and the back brake is not connected.

The headset is the issue. It is not a standard headtube. It is more like a intergrated headset/tube.

Can anyone identify the head set I need to get. The oroginal bottom crown race has broken hence the steering was a bit notchy. It is a 1" steerer with 24 TPI threading.

Just goes to show the modern trend for semi intergrated/intergrated headsets is nothing new.

 

[Old Ned]

From what I remember the PO bikes at one time had odd sized fittings so that (allegedly) posties couldn't take bits off and use them on their own bikes. I'm sure you'll find more info - somewhere!

 

[bm0p700f]

Thats the thing I cannot find any info yet. All I know is the this frame was produced from about 1939 onward. PO bikes with rods brakes where still being made by Pashley in 1983! I figure by the old PO decal on the head tube this would be an earlier bike maybe I should phone Pashley to see if they could shed any light on this bikes headset.

 

[chipper]

http://oldbiketrader.co.uk/ might have what you want

 

[1duck]

From what I remember the PO bikes at one time had odd sized fittings so that (allegedly) posties couldn't take bits off and use them on their own bikes. I'm sure you'll find more info - somewhere!

someone at the top assumed postmen were light fingered? i wonder where they got that idea from!

 

[keithglos]

This could have been made by Pashley, and could have the standard head bearings used in most of the millions of roadster bikes from 1900 to about the 1960's, including BSA, Hercules, Phillips, pre Raleigh.
Loose case hardened rings taking 30 1/8 inch balls, with the crown race supposed to be interference fit. The races were sold in the 1950's for about 4 pence each and sort of self aligned.
The crown race was fitted by banging it down with a bit of 1 1/8 tubing from a scrap frame, without a hammer. The fork crown sometimes needed filing to fit or centre punch all round, or possible a bit of tin can for a shim.
There is a copy of Brown Brothers 1952 catalogue (large wholesalers of comonents) on oldroads.com who are based in Baltimore US, which surely illustrates these parts.

 

[bm0p700f]

This bike has the headset you describe. I take it no one makes these any more so what is the best source for one? I will try old bike trader and old roads any other suggestions? If I cannot buy one I am thinking it may be easier to get one machined.

 

[bm0p700f]

Getting a local engineering company to make up a new crown race and lower cup. Going to use a 1% carbon steel for hardness.

 

[keithglos]

The originals always had rough machine marks and were case hardened. There is very little weight on the lower head bearing, and even less on the top.
If you consider the weight distribution, it's probably carries something like 10% of the total.

 

[bm0p700f]

The aim is to get a functioning headset until a suitable replacement can be found. Maybe the crown race and cup that is being made will last a long time.
To case harden I will have to find potters kiln to get the parts hot ~1000 C and then quench in a salt/ice/water mix as cyrogenic quench is going to be beyond me.