I own and race both brands. The only difference that I can see is that the Zen are lighter and have a better finish, which explains why they cost more.
The Zen are lighter because the backs are milled-out to remove material:
The FSA are not. This is the reverse:
Both the front and reverse have "FSA" printed on it, but the reverse uses a smaller font.
Solid rings are prefered over standard cut-out rings because the cut-out rings warp under heavy sprinters. If you aren't going to warp one, just use the standard Sugino 75 type rings, which are lighter and cheaper than the Zen:
The FSA are the best bang for the buck in terms of solid race gear. They are even cheaper and stronger. But, not as light as the others.
Originally Posted by gtrob
Roadies can run tempo all year as that's what humans were designed for. If you want to be a cheetah, lay around and lick your paws more.
Last edited by carleton; 11-26-12 at 10:57 PM.