If a group of bicycles has riders, then the obvious answer is a peloton, or we could adopt the Italian term grupetto to name them collectively, but these terms really belong to the grand tours.
Cycling in London, and I suspect in other cities, you often find yourself at traffic junctions, waiting for the lights in a green box, perhaps a group of city cyclists could be called a ‘box of’ or ‘boxful’.
Then what about just bicycles without a cyclist? What would be the best term for the ‘collection’ of bikes you fantasise about owning? If we were talking about cars, you may refer to your fantasy garage. As a cyclist I have a fantasy shed, but this isn’t entirely satisfactory.
I’ve searched the internet, and although there does not seem to be a definitive answer, there are plenty of suggestions…
A stable of bicycles – similar to my idea of ‘a shed of’, I guess it depends where you live (although I don’t have either)
A murmuring of bicycles– I have Chris King hubs, so maybe I would have to swap this for ‘a loud murmuring of’ or ‘a buzz of’
A chain of bicycles– very apt, I like the idea of owning my own chain gang
An overdraft of bicycles– only too true
A spin of bicycles – sounds a little casual for some
A quiver of bicycles – I believe a quiver is for surfers, ‘a quiver of boards’
A fleet of bicycles – this is my default term
A bike park of – this sounds too much like a shared affair for me
What gets your vote? More suggestions welcome.