T-Mar to the rescue.
http://www.bikeforums.net/showpost.p...80&postcount=2
The Miyata Sport-10 dates from 1984 to 1986. The 1984/5 model was a 10 speed, while the 1986 model was 12 speed. Specs varied quite a bit, depending on the year. The 1984 model had a plain gauge main triangle made of hi-tensile steel. It was upgraded to CrMo in 1985, then downgraded to Mangalight in 1986. The stays are hi-tensile steel, regardless of the year. The rims may be aluminum or steel, depending on the year. The crankset should be a swaged, cotterless design with what appears to be steel chainrings. Derailleurs are respectable SunTour Seven with stem shifters. Brakes should be Dia-Compe 730 or Shimano Z-series side-pull with safety levers.
There was also a Sport-10FF model that used Shimano's Front Freewheel system.
If the above means nothing to you, then let's state that it is the bottom of the line model and cost $165 US in 1985! It's also quite heavy, at an advertised weight of 30-32 lb.
On the postive side, Miyata made very nice bicycles. Even the entry level models were properly designed, well manufactured and nicely finished. They were excellent value for their price range.
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Carbon: Fuji SL2.1 Di2.......Aluminum: Cannondale Synapse 105........Steel: Vintage Specialized Sirrus
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