[January 29, 2010 from Graham Butler]
[January 29 From Graham Butler]I talked to Bill earlier in the week about the possibility of using elastomers to create a variable force adjuster for the gas shock. I have been thinking about this idea, but I have been having trouble figuring out the geometry. The reason: For it to work well you need 2 converging points on the frame where the maximum lift happens in the low rider position. There are lots of points where you get some lift in low rider position, and then progressively more lift as you morph up. Lets discuss these tomorrow. I also did a bit of research into gas shocks. It turns out that the compressed Argon that I use for welding has almost the a similar individual gas constant as nitrogen (29kg/kg mole for Argon as opposed to 28 for Nitrogen) Both N and Ar are readily available and relatively cheap (nitrogen is used for laser cutting). It comes in a cylinder compressed to 2000psi. If you were to fill this shock with either gas at 2000psi , it would generate ~1700 lbs of force. This begs the question. Why not create a method to fill and bleed the piston. This solves our variable weight problem especially if it can be done on the fly. You could even have a small canister of gas on the bike permanently linked up to adjust the pressure in the piston. Inert gas is relatively cheap....
This post shows the uncut video from our design session at Baron Engineering on Monday, August 17, with John Baron and Alan Ball. Bill Warner mans the camera.
This video tips the scales at a Titanic length of 8 minutes, which in the "dog minutes" of the Internet translates to a major time committment (is that 56 "Internet" minutes?)
But there's a lot of interesting stuff here, including how you can make a morphing handcycle using bungee cords. (no kidding. Shock cord works great)