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I like that idea better than the side mount I was assuming and, yeah, there's a lot of cable pull. RR's rear derailleur shifter goes from close to the handlebars to an angle that's frightening when considering the consequences of stopping short and not staying on the saddle.

Dual links with the shift hand lever pivoting from the top of the tank?
 
Wild brainstorming here, but, what about the 'oven knob' / gas cap style mounted side or top of the tank. The side mount could have a stub inside that could be welded to the head tube, then 'L' to the side of the tank, protruding out like the end of a handlebar with the shifter mounted on it?

Again, I'm no engineer, just a caboose with a lot of ideas! :21:
 
Servo motor would be cool or maybe some twisted rack and pinion type of setup.
 
Lightning Rods?
191a95c2c09b4d26298d75d58506b832.jpg


Sent from my SM-G920V using Tapatalk
 
Wild brainstorming here, but, what about the 'oven knob' / gas cap style mounted side or top of the tank. The side mount could have a stub inside that could be welded to the head tube, then 'L' to the side of the tank, protruding out like the end of a handlebar with the shifter mounted on it?

Again, I'm no engineer, just a caboose with a lot of ideas! :21:
Click to expand...

It's a good idea, but if the grip shifter for this is as stiff as the SA 3-speed, it would be a pain to use such a knob. The large radio knob I have on Interrobang works, but it's very stiff and easy to overshoot when you're trying to pull cable (I think a lot of the difficulty is the little chain on the SA catching on the edge of the axle nut). Fine when releasing cable.
 
Lots of good ideas. It's fun seeing how everyone thinks through solving problems!

@Verrt read my mail right out of the gate. This was my solution from the start but I had to work through the geometry and restricted space first to make sure that it was possible. I mentioned to @Falstaff earlier this week that the reason for the skunkworks project was so that I could scrap it before posting if it didn't work.
To test it I made this crude working model and marked it with a sharpie to check the ratio. The pictures tell the story. The bottom frame shows the marks centered and how much the amount of travel is reduced for the shifter.
Shifter test.jpg
 
Verrt said:
:cool2:

Seemed like the simplest/most robust idea I could think of. But I actually really want to see @macncheese 's ratchet shifter put into action!
Click to expand...
Me too! I am imagining some sort of LENCO racing set up!

So the reduction mechanism has to be set up in a way that will both fit inside the tank and be one piece for all of the moving parts to connect to. For this I started with a typical RRB cereal box 'CAD' drawing.:p
100_5434.jpg


Next it was cut out and taped together for a test fit. It will utilize the tank mounting bolt to anchor it in place.
100_5435.JPG
 
Satisfied that the chassis will work, I transferred the pattern to metal, cut it out and took it to a friend's sheet metal shop and used their box brake to make all of the bends.

100_5445.JPG
100_5446.JPG


The end was left extra long and a couple of holes were left off until I can determine what I will need after everything else is set up.
 
There is some serious Egghead Junior cipherin goin on there.

egghead.jpg
 
As far as I can tell, all of the parts for the shifter are made. I still need to work on attaching the cable and thread the shift arm for the knob before I reassemble everything tomorrow to see how it works.

Doesn't look like much, but it took a lot of work to get to this point!
100_5461.jpg
 
Love the 'shifter reduction' concept! It does look like a lot of work... I know just the patterning takes a lot of time... it's crazy how much time there is in something that will be hidden. But totally worth it :) ... I see a new product line in your future
 
If you look at the shifter handle in the shot above you'll notice that there are no threads for the knob.

Because the shaft is flat plate, it is impossible to keep a die centered over the rectangular piece while cutting threads without it jumping into the slots as you turn it. I wasn't sure if this would work, but rolled up a piece of cardboard, taped it over the shaft, filled it with JB Weld and let it harden for a couple of days.

Here's a picture as I removed the cardboard form.
100_5458.jpg


It was still difficult to keep things plumb and straight as I cut it, but it was just enough to keep the die from completely binding even though the JB crumbled away with every thread cut.

It worked!
100_5463.JPG

100_5464.JPG


Time to put this contraption together later this evening!
 

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