I'm a firm believer in 'reinventing the wheel'. Good luck.
Heh. When I first read the original post, it reminded me of the documentary "Plane Crazy" of a few years back, in which tech writer Robert X. Cringely endeavors to build his own airplane (or "aeroplane", if you will). Not only does he give himself a ridiculous deadline, he also thought he'd "reinvent the wheel" while he was at it.
Envisioning himself as Burt Rutan or something, he was going to fabricate the plane out of carbon composites and locate the engine in the middle of the fuselage, with the prop driven by a drive shaft. A great concept because it balances the weight distribution, but there are reasons why this great concept hasn't flown.
By the time his deadline arrives, he's partially completed the layup of one wing. In the process, he's nearly suffered a nervous breakdown and has pissed off everyone around him.
Giving up on his reinvention of the wheel, he eventually goes to some family operation in Kentucky or somewhere like that, and ends up building a wood & fabric, VW-powered biplane... in a couple of weeks.
Anyway, with that cautionary tale in mind, I heartily encourage the OP because the stakes aren't quite as high as in building an airplane. Just be willing to alter your design to conform to physical realities, and don't be surprised or upset if it ends up being much closer to conventional designs.
BTW, have you designed and built non-suspended bikes before?