Currently building my first fixie - no idea what the frame is though.
I’ve had this thing for so long that I don’t remember where it came from.
Hopefully some omniscient being amongst you recognises it.
Weight: somewhere between beater bike and boat anchor
serial no: 88023042 (an '88 model perhaps?)
distinguishing features: ‘aero’ downtube + seat tube, graphics, BB cable routing, 25.8 post, english threaded BB
Originally built up with a mix of 600 / 600AX bits, downtube shifters on a removable collar, SR post & stem, can’t remember wheelset (long since dead), 6 speed 12t-18t ish screw-on cluster.
My very first road bike which I got as a birthday present from my dad for my 13th birthday had that exact same shimano decal set. The frame was pearl white though and it came with a biopace crankset. And yes, it did de-rail alot.
Anyhow … Shimano to my knowledge was never mass produced a bike frame. I have heard something about when the aero or AX series of groupsets came out, Shimano put together some complete bikes. These were more demo bikes for the shops/trade shows etc and not meant to be sold to the general public. You might have one of these.
Someone correct me if I’m totally off the track here.
Shimano sold (normal) ‘Focus’ bikes in the late 70s or early 80s (probably quit when trying to expand their component business) and the pictured aero frames were half common. Some were sold under Madison, Graecross and other makers’ branding, some purely as Shimano.
I think all of them were examples of brand engineering of a few types of cro-moly and hi-ten frames, probably all made by Tange using everything from Dura-Ace AX down to Adamas AX components. Some of the better and earlier bikes used the oval AX seatposts, requiring oval seat tubes all the way past the seat clamp (with aerodynamic plastic collar!).
There were show bikes also, using early prototype and pre-production components with hand-shaped (probably squashed in a vice) tubing.
I’ve got a frame that looks pretty similar. Especially the cable routing on top of the BB shell, the lugs and the “dimples” in the chain stays.
S/N stamped on the BB shell looks to be the same font. I bought it off a guy in radelaide as well.