Help IDing a frame - S-curve seat tube
 

Hello, A friend had asked me to inquire about this bike that is he going to be looking to sell.. No markings on the frame whatsoever besides the serial number.

-Campy fork dropouts. Nothing on the rear.
-Rear dropouts are track style
-Mostly campy group. Campy hubs to a GP4 rear and GEL280 front rim - tubulars still holding air! Woo!
-Campy 6s freewheel. Looks new.
-Sedis chain

I can grab more pics if needed...
Thanks in advance
Dave

https://cimg6.ibsrv.net/gimg/bikefor...ced77cb7e7.jpg
https://cimg9.ibsrv.net/gimg/bikefor...58d939b20d.jpg
https://cimg0.ibsrv.net/gimg/bikefor...e8be536a1e.jpg

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hello dave,

thank you for sharing this curiosity

first thought regarding frame is wonder if what we see is "as built" or if some of the braze-ons may represent additions since it is the recipient of a respray

chainstays may be fork blades

dropout stops are Simplex or Huret and are manufactured by ALGI

lugs and crown appear French
pump peg is NERVEX and is somewhat anachronistic to be seen in conjunction with the other braze-ons such as front mech, w/b & top tube guides, as by the time these latter had come into fashion framefit pumps were widely available from several makers
NERVEX also offered lugless bottom bracket shells

first guess for possible national origin is France

serial: if read in reverse it could indicate a date of May 14, 1972

one simple check you could make would be to determine headset and bottom bracket thread together with tube diameters

shall look forward to reading what the forum experts have to communicate...

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usage tip -

the short chainstays found on curved seat tube cycles tend to limit the number of usable gears on a multi-gear derailleur drive train due to the crossover issue

many cycles with frames of this pattern are built up with single plateau drive trains


MauriceMoss bulgie Doug Fattic



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Thanks for the info! Thats a great idea regarding the threads.. just another piece of the puzzle... I will check that shortly..

Schwinn made their Paramount model with such a seat tube in the mid-1970s, but I'm pretty certain the OP's pictured bike is not a Paramount. I wonder of the RD mount has been added later?

Jack Taylor, Bob Jackson, Roberts, KHS among others made bent seat tube bicycles.

Is that rear wheel laced correctly?

Yep looks to be laced 3x on both sides.

Maybe so, but I still think it's incorrect.

If it's laced 3-cross, then the spokes at the valve should not be crossing over the valve--they should be almost parallel at the valve (like they are currently at the rim joint sticker), and crossing each other at the rim joint.

This was does not look like a P, but I could be wrong......Here's a P with track drops and a RD hanger....I have on like that too. :D
bikecult.com > bikeworks nyc > archive bicycles > schwinn paramount track
https://cimg4.ibsrv.net/gimg/bikefor...93a3d4a078.png
Best, Ben

Interesting! What was the point of the RD hanger on those??

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multi-use, employed as training bike

bitd enthusiasts would often have a single frame they would set up in differing formats depending on use

common to have three sets of wheels, for example, to use with one frame


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Thats amazing. Never knew that!

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terminology note -

an added gear hanger is sometimes referred to as a "tab"


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The answer, straight from the "expert". :D
Best, Ben

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for a number of years Campag offered a braze-on gear hanger/tab; item number 80/1

out of production now many a yar...
https://cimg0.ibsrv.net/gimg/bikefor...363a06f2a1.jpghttps://velo-pages.com/main.php?g2_v...serialNumber=2

[page from catalogue Nr. 14 of 1960]

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It's "incorrect" in that such lacing increases the difficulty of getting a pump head onto the valve stem, but the wheel is not inherently weaker from being laced that way. Not really wrong, but not right.

That was my thought as well. Its laced correct, but they probably started the first spoke at the "wrong" hole of the rim..

I get that the lacing itself may correct, but to me, with that fault, it was laced by someone who didn't now what they were doing--a first try, perhaps.

Dave, as you know, one of the best ways to increase the sale value of this rather odd bicycle is to identify its builder. As I mentioned on Paceline, it is possible it is just a mediocre frame with ratty paint. It is up to you to distinguish what it really is. We need you to provide more information and pictures. The seat lug seat stay attachment is often where builders do something distinctive. We also need close ups of the head lugs and fork crown. Those can also have defining features. Also we are waiting to hear if the BB threads are English. And what is the length of the cranks and what are the number of teeth? That looks like a very light weight American Classic seat post. Is it 27.2? It can be helpful to measure the seat tube and top tube center to center lengths.

My guess is that this is British built because it appears to be a time trail frame with a very short wheelbase. Time trials were very popular in the UK and road racing was not. I think I counted more than 53 on the front chainring. It has a very short stem. Also the head angle looks pretty steep because it doesn't have much fork rake. It is going to take a special person that thinks this frame is right for them. The heavy back rim compared to the very light front rim means an owner sometime probably changed out the back rim.

It reminds me of a Gillot but I can't find any curved seat tubes online.

Two quick things to mention about the curved-tube bike

1. That tube is probably the one sold by Reynolds. You could bend your own of course but few people did, the "factory" 531 curved tube was nice enough. I have one, looks just like the one on OP's frame. Can't envision using it, but I just like having it. (I'm a bit of a hoarder).
2. I'd recommend taking that Campy freewheel off if you're going to actually ride the bike. Not that they're bad exactly, but they're very valuable and not very durable, with almost-all-aluminum construction (both the cogs and the body). I think even the pros only used them for uphill timetrials or mountain stages.

I used to have one of those, in the older style with the hole for the spring on a Cambio Sport. Or I should say I still have one, but it's brazed to a dropout now. I "un-drewed" my '50s Follis, that came with Campy 1010 dropouts but was drewed, probably early in its life because it came to me with a 1958 Allvit on a Huret bolt-on claw. I know, weird, right? Cutting off a Campy hanger so you could use an Allvit? Who does that?!? A rabid francophile or French chauvinist in the late-'50s is my guess.

On that bike, I actually needed the extra hole for the Sport mech, because the one I installed is a hybrid, Record mech with the sprung top knuckle of a Sport grafted on. It gives the Record vastly more gear range, which I needed because I'm old and fat. It now sports (no pun intended) a 13 to 30 freewheel with a 20-tooth range triple in front. Shifts smoothly to all gears, not maxed out. An original Record (the bronze and steel one, not the later mech of the same name) was happier with a half-step double, usually 5t difference or less in front.

https://cimg2.ibsrv.net/gimg/bikefor...82fb93bd56.jpg

Mark B

Thanks Doug. Its been a busy week but hopefully today will be quiet and i get get all this info! Thanks!

https://cimg2.ibsrv.net/gimg/bikefor...301347b7cf.jpg
I had one of these in the early 80's. Heavy beast.

Im not expert but I dont think these bikes are related.

Ok here is the run-down:
-REAR DROPOUTS ARE CAMPY! (Its pretty worn, and hard to see in the picture, but circled in red is part of "BREV" and "CAMPAGNOLO")
-English bottom bracket
-27.0 American Classic post, but I can start a 27.2 post in it. Although its a little tough, so maybe just needs to be cleaned out a bit?
-57cm ST c-t / 56cm TT
-Cranks are 170mm 52/45 but the inner ring is Sugino, not Campy.
-Spacing is 100/125 F/R

IMAGES

Thanks!