EDIT: Someone in an FB group identified the bike as "Road Athlete". Not sure if this is a brand or a model. Unfortunately, the person who id the bike doesn't have much info either. I was lucky we have the same bike.*
First time posting here. Hope you can help me figure out the brand/frame of this bike.
I recently bought an old road bike that doesn't have any info on the frame other than a decal that reads RS21 in the head tube and seat tube. There is also a remnant of an old decal where the tube shifters were located - it reads "RO" (it's the only part left). The original owner probably failed to remove that piece.
The serial is located in the bridge of the chainstays and not underneath the BB.
Bike details: RD - Shimano Skylark (has LH so it's probably around the 80's era)
FD - No model, only has Shimano logo
Shifters - Shimano tube shifters
Rims - Araya
Handlebar - Alps
Brake Lever - Yoshikawa 7 - F