"Boys bicycle" vs. "boy's bicycle" [duplicate]

Possible Duplicate:
User’s Guide vs Users’ Guide

When describing, for example, a bicycle for boys as "a boys bicycle", should it be "boy's" or "boys"? The phrase is not implying ownership but the type of bicycle, in the same way as one for either sex might be described as unisex.

You can put an apostrophe in it if you want, but I'd write a boys bicycle at least as often as any apostrophized phrase. Either placement of the apostrophe, as well as no apostrophe, would be considered correct by some, and incorrect by others.

In speech, there are no apostrophes, because they're always silent. In writing, apostrophes are misused probly more often than they're used "properly", so most English speakers can't tell the difference. (This is one of the meanings of "More honored in the breach than the observance", btw)

• If it's for anyone except your English teacher (whom you should ask in any event), don't worry about it.

• If it's for a boss, find out what they think. They might not notice, or they might prefer just about anything, and they're paying, after all.

Oh, and before I forget, possessive is not a case in English; rather, it's a noun phrase clitic that gets attached to the last word of a noun phrase, as in

• the Archduke of Austria-Hungary's assassination

where it was the Archduke, not Austria or Hungary, that got assassinated.

A boy's bicycle would be a single bicycle belonging to a single boy, whereas A boys' bicycle would be a about a particular type or brand of bicycles, generically speaking, for boys. I don't think A boys bicycle is grammatically correct.