A mate has an old track frame with a flared headtube that needs a headset put in it. Rather than being just a straight bit of tubing, there’s a cup at each end of the headtube, but they don’t look like bearing races. I’m assuming you can get a headset that sits in the cups? Or is it possible to get a headset that has a longer base on it so that it can sit on top of the cups but still be seated tightly in the headtube?
My new (old) Lewis (or Repco) pathracer is like this. it’s got bearing races that sit in there, with loose bearings. Absolute prick to work with. And yeah, it looks similar to the top pic of the post above. The headset was included with the frame when I bought it, so I was lucky.
I have no idea why I have a normal HS in my frame, it’s perplexing, it may have been a mod made when the dropouts were changed and the bidon/shifter mounts installed.
The ‘old English’ headsets are a much better system then pressed-in cups, not needing frame facing or reaming but self-aligning for minimal bearing wear. Although the small bearings can be a pain, the cups last almost for ever. TDC and plenty of other manufacturers made suitable headsets. Try an old bikeshop or the interweb thing. Tom Wallace in Brisbane had several NOS TDC a few years back but I don’t know now.
Blakey, the internal headtube dimension is the same as normal. I suspect your frame was fitted with the Stronglight because they didn’t want to or couldn’t fit the proper headset. The plastic cups were easy to fit and very light but the roller bearings didn’t tolerate misalignment well.
Most of the Chater Lea headsets I’ve come across used their own unique size.
Cups to hold the races, similar to the current internal headsets but with the races free to correctly align themselves. Being steel to steel contact, there is no problem about wearing the frame.