Bob Girvin was a real innovator in the early days of mountain bikes. His first product, the Flexstem (1987), might have been the first modern offroad suspension device. Later, turning his attention to frames, he developed the Offroad brand with its high forward pivot. Today's Humpbike is a nearly mint Proflex (what Offroad morphed into) model 555 from about 1995. It has janky components and a silly MCU spring, but the suspension works nicely through its 1.5 inches of travel. This was meant to be the peoples dualie selling for about $550. They appear to have held their value nicely, as I just saw and ad for one at $310:
Spindly seat stays drove the shock and, with a large swingarm (for the time) and wide bearing placement, that's about all they did:
Cheesy ATF fork showing the full 1.5 inches of travel possible:
Cockpit is ho-hum:
Proflex brand was relaunched, albeit in name only, with a high-end carbon platform. Unfortunately, the launch didn't achieve lift-off, perhaps because of the idea of a ProFLEX carbon bike created too much cognitive dissonance. Or, maybe it was all the guys laughing in the booth next door every time the Proflex rep had to explain the name.