Welcome to the forums. A frame built with Japanese Tange Prestige tubing and French Bocoma fittings would be unusual. However, it appears the previous owner has added a lot of decals/stickers, so the Prestige tubing sticker may not be OEM. Regardless, the Superbe Pro dropouts are indicative of a higher grade frame. The bicycle appears to be outfitted with primarily 1987-1989 Shimano New 105 but this may be from a donor bicycle due to the Superbe Pro dropouts and lack of pump pegs and 2nd set of bottle bosses which were standard on higher end frames by this period. Also, fully chromed frames were rare by this period and most of the major manufacturer's had lugs, stay caps and/or fork crowns embossed with their identification. Still, the presence of Superbe Pro dropouts indicates it is no older than 1981.

There a number of things I would do in an attempt to identify it:

1. Locate the serial number which may provide clues to the manufacturer and year.
2. Remove the fork and check the steerer tube for a tubing manufacturer's logo and date code.
3. Determine the diameter of the seat post, which may allow us to determine the tubest, in conjunction with the logo from the steerer.
4. Check and report the stampings on the bottom bracket cups, which will allow us to determine the threading standard used on the frame.

Cheers mate.ive stripped the frame down so ill check the steerer tube.also ill put up a photo of the underside of the bottom bracket and ill measure the seat post.

cannot find any serial numbers anywhere.there is a number 3 stamped under the bb with what looks like a centre punch.the seat post tube is 27mm internal diameter.it had shimano 600 crank and pedals.also has a stronglight spidel headset.ill post up some pics

Not to be taken as a slight to your bike, but it appears to be mash up of parts, and decals too. Nothing looks to be low grade about it at all, just that the decals don't mesh up, and it is unusual in its compilation of parts and components.

Oh, welcome to the forum, some folks with deeper knowledge can suss this out for you, clean it up good, service what needs to be taken care of, set it up to suit your riding needs, and enjoy the miles. (All this if it fits you properly.)

Bill

Did you get a manufacturer and date code from the fork's steerer tube?

Nothing written on fork tube anywhere. Its a bit of a strange one

If this was built with Tange, I would have expected their logo and a date code. The same if it was Ishiwata. Columbus has their dove and Reynolds have their stamp but it is near the bottom of the steerer though this sometimes gets cut off, if the required steerer length is very short. Unless the seat tube is a bit distorted, a 27.0 mm inner diameter is a bit smaller than what I would expect for a top end tubeset, including Tange Prestige, which would typically be 27.2mm or 27.4mm. A Prestige steerer tube would also have six ridges on the inside, at the bottom. It's sounding like the Prestige decal is an addition, like the others. Regardless, even at 27.0mm it is a higher end tubeset, even if we can't identify the manufacturer.

The mix of English threading, SunTour dropouts and BCM fittings, in conjunction with no embossing or serial number typically indicates a very small manufacturer, possibly USA. The extensive chroming suggests a possible show bicycle but if this was from one of the nmae custom builders, I would still expect to find a serial number. Sorry, I can't be of much help, other than to say that is no older than 1981, is probably no newer than circa 1985 and is built with a good grade tubes.