That would be the way it works in Scotland. You can't just help yourself to "abandoned" property.Be careful about removing abandoned bikes, you cold be charged with 'theft by finding':
https://en.wikipedia.org/wiki/Theft_by_finding
You can't even help yourself to a bike (or anything else) that has been thrown in a skip, as that would be classed as theft here. @SkipdiverJohn would have to BUY his bikes if he lived north of the border!