Welcome to the new and improved Proflex / K2 Tech Forum!
Here is a pic of the Offroad proflex 550 I bought in 1990. Still in original spec in the main (replaced rear elastomer with some from Slim), and still on the Tioga Pscho rear tyre I put on sometime in the 90's. Only recently changed saddle and pedals for wife to use. Took away some of the pressure to sell it when I got the 657 last year.I got it with the insurance payout for writing off a car with my Raleigh Mirage and it cost just over £500. I had a choice of a 450 hardtail and there was a 750 and a 950 that both had aluminium frames rather than cro-mo with higher spec running gear, but were more than I could afford. There wasn't anything else like it at the time and the 'suspension' did just take the edge off. Fairly sure this is as early as it gets - memories of youth starting to get hazy.It's still a good bike to ride, if a bit on the heavy side. Ade