Nice bike, a nice one for a hundred let alone ten.You see the date so..?? I'd have guessed in was 83-87 I have a Miyata with similar comps.,a 1980. the parts are typical for a five hundred dollar bike of the day.. THe diacomp brakes work well,I still ride my bike with the Suntour friction.Araya rims are cheap but good Mine still are serviceable. The Sugino cranks are nicer than the SR's,they have a 50?-40?,the sr's had a smaller inner chain ring as well. Probably called a 23inch HUH ? It's a great find.A size smaller would suit me,I don't believe thay had 56cm frames,I think they were STILL going from 21,23,25" etc.The Shimano bikes were a notch higher in price.I liked Suntour as much.Plain to see it's a fairly good frame.That's easy to verify.