Hi Max - aren't you another HGTTG character? Now, Douglas Adams would be able to answer all our questions!

Can't find Marty's challenge, but give me time.

Anyway. Hmmmm, tricky one.

Contrary to popular belief, the collective noun for fish on bikes is NOT a "shoal". And indeed, a group of fish on bikes does not behave like a shoal, which has something of the qualities of a single organism (if you see what i mean). The same, as I like to call it, "negatively-gestalt" quality actually applies to any group of creatures placed on bikes, however socially-orientated they were beforehand.
Many experiments by maladjusted animal behaviourists have firmly established this fact.

I have to answer this with another question - what do you call a collection of wheeled vehicles containg drivers?

Let me rephrase that, before you reply "a jam".

What do you call a collection of cyclists?