Ken Rockwell for bicycles - but good?
For me, Rockwell is basically an encyclopedia of practical data on lenses (I don't even use him much for camera bodies). Same as Sheldon's site is an encyclopedia of data on bikes. I use them both when I want to figure out how big / heavy / compatible with X something is. Much as I wouldn't bother trying to look up "is X good for me" on Sheldon's site, I wouldn't do so at Rockwell either.