ID Help- Possible TI Miyata - Ridge Runner

[snicker7]

I've been jonesing for an old titanium frame for a while, and something interesting popped up for me today, but I have no idea how to identify it.

here's what i know
Looks like it might be TI
Suntour XC Sport mechs front and rear
Suntour XC III pedals
Shimano biopace triple chainring
Shimano SIS grip shifters
Suntour brake levers

The only decal on the bike says "Ridge Runner" on the top tube.

Not sure on the brakes, i think they are Suntour as well
I'm really looking for help identifying this bike. I'm going to check it out in person tomorrow (magnet in hand), but i'm trying to figure out to see if it's worth the asking price.

 

[snicker7]

https://www.ragandbone.ca/Miyata/miyata_selector.html

Looking at these catalogs, I am thoroughly convinced it is a Miyata- rear brake placement matches ridge runners from 86 and 87

however- the ridge runner was a lugged steel frame.. this is welded, so it seems more like it might be a Skyrunner frame. decals can't be trusted, there's nothing on the downtube.

this is a mystery bike to me

 

[DrJo]

It's not ti and it's a giant I think or perhaps a schwinn, the twin rollercams reduce the potential options massively. Old? yes. Rare? yes. Ti? no.
If you pass on it I'd be interested...

 

[snicker7]

so i ended up snagging it. definitely steel.

Serial number on the bb is one line

DS65223820

the seller said the bike belonged to his uncle and he was the original owner. it's in excellent shape.

i'm thoroughly convinced this is a mishmash of Koga Miyata ridge runner stuff from 86-87, but i can't confirm with the serial number. Some info on the internet says that Miyata contracted with Dodson for frame manufacturing- and any frames they did were listed with "DS". however, that info also says they are on two lines, and the first two digits correspond to year, etc.. so this doesn't exactly match up

checking the catalogs gives me a frame that looks remarkably similar to the 1987 Koga Miyata Ridge Runner (under mount rear brake)
https://drive.google.com/file/d/1lqezCC ... kbgfF/view

but the bars and stem match the 1986 catalog (but with Shimano SIS grip shifters)
https://drive.google.com/file/d/1ygALCw ... BS1dH/view

but the components don't match up. the brakes are suntour XC power brakes.

all in all, for what these components are valued at today and the condition of the frame, i'm absolutely stoked--- it's such a cool bike. however, i can't let the mystery go.

 

[snicker7]

maybe i'm off there too:
viewtopic.php?f=6&t=291418

this 87 KM Ridge runner is lugged and not butted