A bike I found with no wheels lying on the pavement in Koln germany but what is the frame was bare of logos and serial numbers had no wheels but shimano deore lx groupset. It is made of steel but quite light that main beam is really thin. how is this frame type described someone suggested epsilon frame but no results Anyone seen one before?

It's the kind of frame that was popular in the seventies for one-size-fits-all bikes and folders. Not sure what it's called (if anything). Interesting, if it is light and your calves don't hit the stays when riding. You could probably fit 700c wheels.