I had to work 3:30a to 3:30p today (not normal, I had a software implementation go live today). But none of my users are working on sundays so any issues will start up for me tomorrow.
So, I designed (well, stole the design from some super smart person who invented the 'monostable multivibrator') a circuit to make a quickshifter for the bike transmission in the fiat challenge car. Here it is:
The idea is with bike transmissions that they can be shifted up (2 to 3, for example) without the clutch, you just need to release the torque on the trans for a moment. This is usually done by rocking your throttle hand while applying modest pressure to the shift lever. With full throttle torque on the trans, it will not shift, but as soon as you release the throttle just a bit and free up the teeth, the trans will snap into the next gear. Yes, many people are quite good at this.
But, you can make the process repeatable for even a gorilla driver like me by making a quickshifter that kills the engine for a very short amount of time (like 50 milliseconds). If you trigger the kill of the engine with the moving of the shift lever, you now have a system that will auto-upshift for you and you can keep the throttle matted. Basically you floor the throttle, and when you want to shift you start pushing on the lever. As the lever moves (right before it gets to the point where it starts moving the shift forks), it hits the microswitch that initiates the monostable multivibrator circuit that cuts the engine for 50 or so milliseconds, just enough time for the shifter to find the next gear with the unloaded transmission.
How am I going to kill the motor you ask? Well, first I'm going to try using the kickstand switch - the switch on bikes that kills the motor if you put it in gear with the kickstand down. If that doesn't work I'll think of something else.
This is a simple circuit and I could likely buy all the parts for less than $5, but for the challenge it would be cooler if I can scavenge this stuff from an old broken VCR or something. So now I'm off to find some broken junk in the trash!
p.s. if you are building or want to learn about circuits, falstad.com/circuit is about the coolest site known to man. Build, test, and watch your circuits function. It's an entire undergrad degree packaged in one simple java page.