I'd seen this Miyata up high in the racks since late 2016 when I first started visiting a semi-local, suburban co-op, but even with it's $120 price tag I held off, until now!
What kept this bike from selling was a mostly-superficial crusty-rust problem, covering the headset and giving the toptube a distinct structurally-questionable appearance, all the result of being ridden mostly(?) on an indoor trainer.
There was also a beat-looking, off-brand saddle, a .2mm-too-small generic seatpost and genuine hardware-store SAE screw/washer/nut clamping the frame ears!
After I negotiated for a slightly-lower price, and later had it in my kitchen, I decided to try a new approach to help evaluate what was going on underneath all of the rust, including rust residues over the surface of the paint. I mixed a tablespoon(!) of oxalic acid powder in a 8oz glass of water, heated it up to dissolve all of the powder, grabbed a toothbrush and had a go.
Within an hour, all of the rust was gone from the headset, frame, brake springs, bolts and etc.
Amazingly, relatively little evidence of it remained, but for a small area surrounding one toptube cable housing guide and the headset top nut. This was rust-be-gone in fast-forward, but with no damage to the paint and with the chrome left gleaming after I finally took it outside to spray down the entire bike with water from the hose nozzle.
I put in several hours, rebuilt the bb, serviced the original cabling, replaced the chain, then fitted a larger UG 7s cassette on a different set of wheels (since the bike's rims were mis-matched, though on non-original 32h Superbe hubs).
I got to use the bike for today's balmy (38F) "Fast Friday" ride while also riding to/from the event, all 45 miles on some pretty old 21mm tires inflated to 95psi.
Went well, and the goat-head thorn that punctured the front tire on the last(!) mile even happened two doors down from the LBS, where a floor pump awaited.
It might be a keeper since it fits well, but I'm not liking the bar/tape combo, looking for better grip and control here.
Here's the 1984 Miyata Nine-Twelve after yesterday's overhaul. I'm not feeling quite so bad now about selling my Seven-Ten about fifteen years back!
