1940s stem clamping

[porteous]

I'm restoring a late 40s racing bike which has just had the frame and forks refurbed.
The problem is a new threaded tube was put on the forks and now I am not sure how to secure the stem, since the old Raleigh method uses a clamp in the headset and I assume that the threaded tube had a slot to allow the clamp to work, but cannot remember!! Help needed before I feel safe to get the hacksaw out!

 

[mattsccm]

No. I have a clip head set which I think you have.Mine has a top race , ie the bit that sits on top of the top bearing, which has a nut and bolt ot tighten it. Above that is a spacer or two and then a large nut just like on traditional headsets. After fitting balls etc slide the clip bit down onto the bearing and after any spacers fit the top nut which is tightened to adjust the bearing. Once all feel right tighten the bolt on the clip bit. Its a bit like a mix of a trad head set plus the clip bit. In theory doing up the nut and bolt is not needed as all other threaded headsets didn't have them. do not slot the steerer. Haven't got a ny pics but if you ask and are patient...............

 

[PpPete]

Old threaded 1" steerers all had either a groove or flat down the back. The washer under the top nut in the headset engaged with this to stop the whole thing unwinding.
Raleigh were 26 tpi
Everything else was 24 tpi.

 

[porteous]

Stem

Thanks guys, my problem is really with the stem, which does not have a stem bolt and wedge, and was held in plave by the clamp you describe between the top race and clamping nut, I just cant see how this works. Does it just squeeze the whole tube enough to tighten it? I would like to use the original stem, but do have a contemporary one with a stem bolt if all else fails.

 

[mattsccm]

How about a pic?PP above. my prewar Dawes does not have a flat or slot and I know the forks are original.

 

[porteous]

Picture

Good idea! You can see a pic here with the same system, on a 1947 Lenton. The Rudge Clubman is identical. The head clamp fits between the top bearing upper cup and the locknut. Note the stem, without a clamping nut.

http://www.flickr.com/photos/74418119@N00/2851490310/sizes/o/

http://www.flickr.com/photos/74418119@N00/2851488346/in/photostream/

 

[mattsccm]

Looks the same as mine

 

[jimboalee]

Old threaded 1" steerers all had either a groove or flat down the back. The washer under the top nut in the headset engaged with this to stop the whole thing unwinding.
Raleigh were 26 tpi
Everything else was 24 tpi.

Except Peugeot who had 25mm x 1.

The washer with the tab that slipped down the slot was to assist setting.

The racenut and locknut were held by seperate spanners and one wasn't supposed to move when the other was turned.
There were also paper thin bronze washers between the nuts and tab-washer, which were supposed to be well greased to allow a lovely feel to the setting process.