i had a bike with DuoTracks on it that i got from goodwill for $30. the bike itself was a pretty good bike for the money, it was 27lb cromo with acera drivetrain. great for a beginner. the duotracks though i wouldn't really call them suspension forks, maybe just shock absorbers. they would only compress if you hit something pretty hard. like a curb at 8mph, then they would suck up and help you over it. other than that they were rigid, and heavy. they are also unadjustable and unserviceable. they are pretty strong though they didn't flex at all. also the rebound on them will just about throw you off the bike. I'd get them if they are free or close to free, and if you're not going to be using the bike for anything aggressive, and if you don't care about weight. I wouldn't pay more than maybe $10 for them new, $5 used, maybe. For a little more money you can get a modest rockshox or RST fork on ebay and probably be a lot happier with it.