Using 3-speed hub, how to make auto-shift?

[Urban Fatbiker]

I'm just thinking most of the 4T's would output too much torque on shifting for it to last unless babied. that's why shift kits for the CG's are way more popular they spin fast but don't really pound the cassettes

The engine will be 49cc or less. The power-shifting is the problem I see with the kilduff, a rider gets used to the response, a dummy throttle will smash thru it.

Hence the Arduino. For this to work, I need inputs for throttle position, brake, and drive RPM with outputs for shift and throttle.

Logic will have to handle constant accel, cruising, hill climbing, and hard braking.

Also transitions between all of the above.

Finally, a manual single-gear bypass to get home if something fails. Skip that part, may be some more pedalling involved

 

[Sidewinder Jerry]

The engine will be 49cc or less. The power-shifting is the problem I see with the kilduff, a rider gets used to the response, a dummy throttle will smash thru it.

Hence the Arduino. For this to work, I need inputs for throttle position, brake, and drive RPM with outputs for shift and throttle.

Logic will have to handle constant accel, cruising, hill climbing, and hard braking.

Also transitions between all of the above.

Finally, a manual single-gear bypass to get home if something fails. Skip that part, may be some more pedalling involved

Like the LandRider rear derailleur when I spoke with Brain he said his shifter could be adjusted to change at certain wheel rpm's/speeds.

 

[Urban Fatbiker]

I found two here that did it, but, no followup on one, the other blew thru a couple of Shimano hubs. Looking more iffy unless I can stop the sprocket, or extremely low idle with a dependable autoclutch on motor.

Not looking good so far for any proof in the wild for a hub driven by engine rolling for more than a few dozen miles.

Electric, different. Motor stops, no clutch needed, can even lock the rotor. And this next one will not be electric.

 

[JerboaJohn]

it's the money/resource/time thing. you'll have a transmission worth 1200 value (solely my estimation) of parts, fabricating, time developing so it's only be practical on like a $4k custom build.so a $100 engine, 4-500 bike, and put a $1200 tranny on it. get my drift?
I'd puzzle on the most practical way to make a shifter bike. unless you really really are building a high end rig,, props to you!!

someone said a 2 speed auto shifter is the holy grail...

 

[Urban Fatbiker]

Would this be more doable with a 2-speed hub? I mean, for 24mph top end, and street-grade hills using 49cc? Just from my sprocket awapping, it seems it would be enough.

Not greedy for speed, just need to pay attention, and try to keep up.