Mystery 1978-1981-ish road bike

[Rossero]

Hello fellow riders! I'm new to this forum but not new to cycling. My Collection of bikes is getting out of hand and yesterday was no exception. I picked up this bike for free through Facebook because I just liked the look of it. Because it was free I didn't ask too much questions, didn't know what the condition was or what the brand of the bike was.

But once home I became intrigued, there is no brand on the frame and the badge has been removed. It might be that at least the headtube has been repainted but it could be that the complete bike is repainted, but most of it looks original and there is no indication of brand decals underneath the paint.

The bike (almost) has the full dura ace 7200 groupset, only missing the front derailleur which has been replaced by an Altus one. Because of this I expect the bike to be from around 1980.

The only information I have on the frame is the serial number: G957690
And that the seatstay has a hollow detail where it meets the seat tube.

The rims seem to be Belgian (Weinmann) and the stem/handlebars Japanese (SR)

This is the bike:


And here a lot of detail photo's:


The question now remains:
1: does anybody know what brand or even model it might be?
2: Is it worth fixing up/restoring? The driveline+tires need to be replaced and I need the original front derailleur.

I hope you can help, thanks in advance!

 

[Rossero]

And here are the last 3 detail photo's:

 

[Jonny69]

I want to say it’s a Raleigh. It looks very Raleigh-ish but there’s no Raleigh script on the tops of the seat stay, so I don’t think it is. I think Dawes used that style seat stay top with like a leaf shape painted on.

Over bottom bracket cable guides is a 1970s thing on English bikes but you’d normally expect a general lack of braze-ons like a band-on shifter mount.

I’m trying not to get distracted by some of the older components but my gut feel is it’s an early 90s frame.

 

[Frankenorange]

Late 70's early-mid 80's i reckon. Could be low end Reynolds tubing and not gas pipe. Gear lever bosses could be an add on before a re-paint?

For free it doesn't really matter and it looks in good fettle. Definitely worth putting some new tyres, guards, and lights on for a winter trainer. Raleigh? Dawes? Carlton? Halfords?

Waddayareckon @Guinessisgoodforyou ?

 

[Rossero]

Over bottom bracket cable guides is a 1970s thing on English bikes but you’d normally expect a general lack of braze-ons like a band-on shifter mount.

I hadn't even noticed the over the bracket cable guides, that's something I don't see on a lot of bikes indeed.

Gear lever bosses could be an add on before a re-paint?

Could be, but it seems a lot of hassle? I disassembled the shifters and I can't see any evidence of a hack job, but it could be well masked by the paint.

And it also needs new chainrings, chain and 5 speed freewheel for what might be a bit of a bodged together bike.

But, strange twist, I didn't have to look far to find a similar bike...
I present to you my un-fixie Giant Peloton hanging above my piano






It has the same shape seatstays, lugs and cable guides on the top tube


It also has a frame number starting with a G, although it is shorter (older?). But G for Giant makes sense


It also has over the BB cable routing. Although it has a single central mount for the shifters on the down tube. And it seems like all Giants either have over the BB routing with central mount or side mounts with the cables going underneath. So that is strange...


And another strange detail is that the Giant badge has two rivets and the mystery frame only one central hole. But the lugs are, again, very similar. Giant might also explain the Japanese stem and handlebars. But I just can't find any Giant bikes with these frame details...

I'll keep on looking (facepalm that I didn't even look in my own Livingroom in the first place) but if anybody has more information or insights they are very welcome! For instance, did brands build their own frames or can it be a different brand from the same frame builder? And might there be bikes shifters on the side and cables over the BB or is cables over the BB only used with shifters on top of the downtube? Which would make sense but would suggest my frame has been tinkered with, which seems a lot of faff for a bike like this to me... Or was that a 'normal' conversion back in the day?

Thanks for the reactions thus far

 

[Rossero]

I'm starting to believe that it might be a Koga Miyata (was closely affiliated with Giant) from this era:

https://www.retrobike.co.uk/threads/1979-koga-miyata-proracer.420122/


This particular model is missing the drop out set-screws behind the axle, but a lot of Koga's seem to have it. And there are shifter mounts on the side of the frame while having an over BB cable routing combined with the dura ace EX group. Does anyone know how Koga framenumbers were formulated?

 

[Rossero]

Pretty sure it's this bike:

https://www.retrobike.co.uk/threads/koga-miyata-gents-luxe-s-1979-on-hold.240185/

A Koga Miyata Gents-Luxe-s from 1979

It checks all the boxes, all the same components and frame features. The only thing is the frame number is starting with a G, but Koga had letters for manufacturing year. The G suggests 1978, although Google doesn't agree that the 1978 bikes had these frame features. But close enough I guess!