Is this fork structurally sound?
 

This fork looks ridiculous. What is the point of the center hole? It looks like it would break. Do you think it is structurally sound?

http://bikeforums.net/attachment.php...hmentid=513995

Probably part of a wheel retension system that includes a washer with a lug on it that fits into the hole to keep the wheel from dropping out/off if the quick release fails or the wheel nuts loosen.

While I agree it is not a good design, think of how much pressure is on a bicycle chain with its tiny pieces of metal, and how they manage to not fail (at least not from the metal tearing apart).

It's not a big deal, although I'd have liked to see the hole a bit more centered.

For bending, the stresses on the structure is at the highest at the edges. At the center there's virtually no stress, a principle highly exploited in lattice girders.

And since a bike fork is almost only expected to see fore-aft bending, that may well still be strong enough.

The design might make the fork fail a bit earlier during (accidental) exposure to sideways loads.
But the ability to continue riding AFTER an event severe enough to throw you to the ground isn't a safety issue.

Yep, from what I recall of my department store bikes in the 70's and 80's, they all had those holes for a retention washer, exactly as you describe. The forks survived all of the abuse that a young teenager could dish out. :-)