Since I now have my instant seat tilt adjustment system mostly working, and blabbed about it on BROL, I figured I should go ahead and start this thread on it. I'll update it as new things happen with the system.  
 
Since a more upright and closed riding postion seems to be better for climbing, but a more reclined and open position the most aerodynamic for the flats and downhills, I decided to build a system that would let me make instant seat tilt adjustments on my Corsa. I call it the Quick Recline system.
 
The system uses small pneumatic cyclinders and springs on the seat stays, and a miniature pneumatic valve on the handlebar. Basically here's how the system is supposed to work: To lower the seat, I flip the valve toggle handle open, which lets my weight lower the seat. When it reaches its lower limit, I flip the handle back to lock the seat. To raise it, I flip the handle open, lean forward to unweight the seat and allow the springs to raise it, flip the handle to lock the seat, then lean back. All of it works well now, except for the valve. It will only lock the seat in one direction, so I lock the seat up, but when I want the seat down, I just leave the valve open and let my dead weight keep it down. I have a new valve ordered, which I hope will fix this last major problem.  
 
If you want to read all about the technical aspects of the system, you can go to my web page on it. For most, that is probably more than you ever wanted to know about it.
 
Here's a photo of the seat stays, showing the cylinders and springs.



In the next photo, the yellow arrow is pointing at the valve toggle handle.

Bud, I'm officially impressed.  Very cool!

That's pretty cool, Bud.  I remember you saying that you were going to try to put this together, but I never guessed it could actually be done.  The engineering looks very professional, and thinking back on some of your other projects... what is it that you do for a living?  I originally thought that you worked at some sort of a welding shop.  Then I thought, based on this forum, that you were a software developer for Spinnerbaker.
 
But I digress.
 
I get that the rear seat supports collapse and telescope by means of the system you've developed, but don't you have forward/aft positioning problems when you change the angle of recline?  From my own experience, I've discovered that for each hole that I lower the rear of my seat, I must move the seat bracket forward about 1/2" to maintain the correct leg extension.  I don't recall your mentioning any sort of fore/aft adjustment in your design, so do you set up your seat for your max recline and then just cope with shortened pedal strokes while the seat is less reclined?

You are my hero - and ten times smarter than Wile E. Coyote.
 
....Bud Bent - supergenius!

I am way impressed with your result. From a thought to reality, that's what its all about.
 
So bud, can we tap you now for small machining projects?

Say, Bud, what's your current thinking on the "instant adjust" system, and its functionality?  Have you been utilizing it, and what do you think about it a couple months later??

Here's a photo of the latest version. It has a longer spring, so I get pretty much the full 1 1/2 inch travel of the cyclinder, as well as a much stronger lower stay. I fabricated it out of aluminum tubing, smashing the lower end in a vice, grinding a radius on it, then drilling. It seems very sturdy.
 

Quote from aikigreg on Sep 15^th, 2007, 5:21pm:

 
 
Umm... why do u think i married the guy!

Quote from MrOverdressed on Nov 13^th, 2007, 11:18am:

 
I'm not sure it will ever be worth marketing. There are bound to be other riders who would like an instant adjust. But, every bike and every rider are different. Just finding my own preferred range of adjustment took a lot of tinkering. My present version doesn't allow for the wide range of setups necessary, and I'm not sure I could make an affordable version that does.