1972 Columbia Tourist Expert III, Columbia Roadster
Mono chain and seat stays.
My old Columbia has a mono chain stay (the chainstays are actually one tube which is formed like an extremely tall U and then joined at the bottom of the U to a short tube which connects to the BB) and I always thought this was peculiar, it seemed to be that this would be given to more side to side flexing than conventional chain stays.
Now I'm seeing a lot of new bikes that have these mono seat and chain stays - are they stronger/lighter or somehow better than the traditional designs? I'm just wondering what the reason behind this is.
They are cheaper, some respects they also work out well in situations where the exact part you are after may not be available: really large bikes, possibly some 29er projects, or specialty things like the Bike Friday, or super long stay touring bikes.