I found this frame on the internet recently without any further information and wanted to get it back on the road. I'm now trying to identify it and find out who may have manufactured it and would appeciate any help.

What I know:

-Nervex pro lugs (bottom bracket says NERVEX 59°3064°D22B38)
-Stonglight headset
-Campagnolo dropouts (1010 "modified")
-Original Paint seems to have been a light red, almost orange
-pretty light for an old Steelframe (exept of the fork)

No idea. But there are some nice pointers; fork crown, badge hole(s) and of course the serial number. Does the fork match?

Not sure if it matches, but it also has Campagnolo dropouts. There is "XS" stamped on the steerer tube.

I believe the Nervex BB shell is a French Reference 3103 with 28 mm DT and ST nozzles, so it's most likely made in France.

The fork is unique, identify that and I think one could identify the bike. I don't think I've ever seen a bike fork like that. Yes, bike forks can be added on later but usually not. I would not rule out the possibility that it could be British. That fork could mean, an extraordinary bike but let's see what others say.

DT and ST are 29mm, so 3103 seems to be right.

I think I found an image of a similar fork, I doubt if it is this maker but we might be looking at a frame made by an independent maker. In saying it is a similar fork, obviously it is a different make of fork.


https://www.classiclightweights.co.uk...rs/holmes.html

Holmes of Welling, I think there is a space there where one could stick their little finger through the open area at the sides of where the brake hole is on what looks like a black fork. British made? They made some sharp looking bikes cosmetically as well.

Those fork crowns are generically known as "twin plate" crowns, and were often found on high end bikes from Cinelli, Rene Herse, Hetchins, and others. They're very attractive IMHO.

Google "twin plate fork crown" and get an eyeful.

Coincidence? "SX" on the Fork and also on the Frame. To me they seem to belong together. (Sorry for the poor Foto quality)

Did you measure the diameters with calipers? French DT and ST O.D. should be 28 mm, and Imperial diameter tubing (English and just about everywhere but France) should have DT and ST O.D. of 28.6 mm.

French chainstay nozzles should be 22 mm, while English should be 22.2 mm.


EDIT - The paint looks pretty thick. I wonder if that's messing up the tube diameter measurements.

Yes, measured with caliper. Exactly 28.8mm (including unknown amounts of paint) so it seems to be 28.6mm Tubes. The chainstays are 22.25mm (with a much smoother paint surface, so they seem to be really 22.2mm). So itīs most likely not French?

Correct. It sounds like English tubing.

Nervex Ref. 3103 English BB shell...

Pretty frame, does look high end. I assume they modified by adding an adapter over derailleur hanger? Can't tell but looks that way on phone.

My guess would have been Paramount but Scooper would have already identified if it were.

It does have similarities to a 50s/60s Paramount, but the serial number format and location plus the twin plate fork crown (assuming the fork is original) pretty much eliminate that possibility.

I have seen the serial number stamped into the upper part of the seat tube in Allegros and Capos only, which would make it a Swiss or Austrian thing.

What other marques (and nationalities) have had serial numbers in this location?

Where did it come from? US? Europe? Looks French to me.

That's what I thought too, until the OP measured the O.D. of the tubes.

I guess the next step is to figure out what the BB shell threading is.

Bottom Brackets Cribsheet | Sheldon Brown

Allegroes (Allegros?) used a small brazed-on capsule-shaped badge for the serial number, plus usually metric tubing and usually Georg Fisher cast BB shells plus usually BCM headlugs (tho not always) so I'd vote "not Allegro".
A very handsome frame, curious to learn what it is...are the forkblades round?

Also curious why there is so much thread showing on the NDS BB cup (Stronglight BB unit?) ...that
is strange unless it was shot when halfway removed and the lockring screwed back down

You got a head badge hole so the spacing between the 2 holes might become a clue

I am saying this is an English bike frame.

Itīs either a Swiss or a French (modern, not that obsolete one) thread. 35 mm X 1mm right and left.

A Campagnolo 74-SS-120 barrel with a brazed in fixed cup was used. (Guess the thread must have got damaged once) A framebuilder is going to fix that for me.

EDIT: Hey wait! Thats a 74! Why? We have a 68mm Housing here. The guy that modified the rear end drop outs seems also to have messed around with the bottom bracket. Now iīm getting confused!

The forkblades are round.

By the way, i bought it in Germany.

Appreciate your help so far guys! Incredible! Thanks a lot!

I wonder what the fork rake/offset is. With round blades, the fork was probably made for a track bike.

Here's an easy way to measure the rake.

Having a 74-SS-120 BB in a 68 mm shell is strange, for sure.

Measured like that and i got a rake of 74mm

Wow! I think something's wrong. Road bikes with ~73° head tube angle and 700c rims typically have fork rakes between about 40mm and 45mm for a trail of around 60mm. Track bike forks typically have even less rake.

74mm of rake would result in a trail of only 26mm (given the same head tube angle angle and wheel diameter). Handling would be very twitchy with that much rake and very low trail.


Could you have left out the last step where you divide the difference of the two measurements by 2?

No, no, itīs really 74mm. Strange setup!