Is this a mid-90s Brigg-built Reynolds 531C frame or... something else?

[RetroDavy]

I was recently gifted an intriguing single speed road bike. The frame has been powder coated white. There are no stickers, previous colours or other clues to its identity, other than a 6-digit frame number under the BB: 906401.

Barely perceptible marks under the coating seems evidence of the derailleur hanger, down tube shifter bosses and rear derailleur braze-ons having been removed before it was painted.

Frame size is 60cm (C-T). Seat post fitted was 27mm. Headset fitted was Campagnolo Mirage but I am 99% sure this wasn't original (the stack height was wrong with lots of thread showing inside the headset nut, and I'm not even sure the fork race was right for the headset). It has Gipiemme fork ends, not sure about the rear drop outs.

The frame details all seem very consistent with the higher-end 1990s Brigg-built Claud Butler (e.g. Criterium) and Holdsworth (e.g. Professional) road bikes in the Retrobike catalogue archive. But then the frame weight is only 1875g, and the fork 720g. It’s lighter than I understood 531 Competition to be.

So, the question: have I got what I think I’ve got, a later Brigg-built 531C frame converted to single speed or… something else? Retrobike wisdom needed!

 

[RetroDavy]

More photos...








Those are all the pictures - what do you think?

 

[Guinessisgoodforyou]

A
Nice frame, I think it will remain a mystery.

 

[RetroDavy]

A
Nice frame, I think it will remain a mystery.

Thanks, I think so too.

And there is something to be said for mysteries; plus an already modified frame means originality is Not A Thing.

On the other hand, the arcane knowledge of Retrobikers is both deep and wide and I won't be surprised if someone identifies it from some impossibly small detail. Then I can fit an appropriate tubing sticker to it in good conscience!