Wow! Is your middle name Miyata? Hehe, you know this family intimately. Here is a photo of one of the Dia-Compe arms and just as sure as you said, they're 980s.

Dia-Compe 980 (from 1984 Miyata Terra Runner)

Not only did you pin down the exact Dia-Compe model number, but I think you've probably corrected me on the model year as well. I bought this bike new, but can't remember if was '85 or '86 and at the time I never really fixated on what the model year might have been. The last couple of years, however, taking more of interest in this kind of minutiae, I tried, but failed to nail down the model year. I did find some year/serial number codes but as I recall the person who supplied them refused to stake his life on them..

My Terra Runner's serial number is: MW68465

One of the reasons I wanted to try making my own straddle cable was to have the ability to adjust the height of the yoke. I have a rack and fenders on the rear of my Terra Runner and the straddle cable does rub slightly on the rack's horizontal attachment arms going to the seat stays. If I could only lower the yoke by 5-7mm the issue would disappear. Can't do that with a fixed length straddle wire because then it would be too loose. It's not a do-or-die thing at all, afterall, everything is original equipment and neither rack nor fenders were on the original.

Thanks for weighing in. You're first person I've ever encountered with the same Miyata!

bashley