I concur. The subject bicycle is late 1980s Sekai Mountaineer. It is entry level, as evidenced by the nutted hubs, steel crankset and claw mounting for the rear derailleur. The components level and lack of tubing decal points to frame made of a hi-tensile steel.|This is supported by the fact that the equivalent Mountainneer models issued under the Norco brand, were hi-tensile steel.

Norco had purchased Sekai from the Velocipede Company in the early 1980s. Velocipede Company was a Seattlle based bicycle shop that expanded into the mail order and wholesale business. The Sekai brand had been created in 1971, with the bicycles being sourced from various Japanese contract builders via the Shin-Wa trading company.

I would appreciate the serial number for my database.TIA.