Unique gearbox for weedeaters.

I give credit to anyone who can supply power directly to the sprocket, and not use a Rag Joint. Safe Bikes are important. Your pictures don't show enough. I'd like to
see an uninstalled one, and installed one, and a price / shipping cost ?

Good luck, you seem on right track . I also must ask, can the deraileur take the
torque of an Engine ? Extra, clutch side kill button, might make sense, kill mag,
shift, release button.

An new SRAM S7 derailleur can withstand full powershifts from a 2.8hp Tanaka 47R engine.

Ask me how I know.:giggle:
 
I recently posted details of my custom gearbox for weedeater type engines, I am quite proud of it. I got some great feedback and it started me thinking about building them from home to sell.
would anyone be interested?

I'm interested. Then I can move my engine off my lap, then lower into the frame.:giggle:
 
I give credit to anyone who can supply power directly to the sprocket, and not use a Rag Joint. Safe Bikes are important. Your pictures don't show enough. I'd like to
see an uninstalled one, and installed one, and a price / shipping cost ?

Good luck, you seem on right track . I also must ask, can the deraileur take the
torque of an Engine ? Extra, clutch side kill button, might make sense, kill mag,
shift, release button.
I've read that question, in diverse forms, so many times I am really tired of it.

There is not a small engine made anywhere that can generate the torque levels produced by a 200 pound human standing on a pedal at the end of a 6 inch lever arm. Dérailleurs are designed to handle enormous per square inch loads on all components. Torque is NOT an issue - vibration can be.
 
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Derailleurs never see any torque transfer anyways, unless you are pedaling backwards or trying to bump start an engine through one (don't bump start an engine through one, you will most likely ruin it). While propelling the bicycle forward the torque load is applied to the top run of the chain only. The bottom run is just the chain following through in a full circle.
 
I have some other posts on this site you can check.
As far as cost, I don't know. This is a one off built at exorbitant expense and uncounted hours.
I used mostly off the shelf parts and designed it to be easy to manufacture, but the next one will be a prototype too.
How much do you want one?? Seriously, if enough people were interested I'd love to take this project further.
I did use it initially with a derailleur, it worked fine but I'm not a fan of external mechanisms.
I didn't bother putting a killswitch on it but I do have one.

"kill mag,
shift, release button"
I'm not sure what you mean here.
I am using a gx31 which probably gives me about 700 watts at the rear wheel so it's not legal on the road in Oz. I use it in the mountains anyway.
Thank you for your encouragement.
 
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I was assuming, we were talking Gas Engines, my thoughts were to kill Magneto
by pressing kill button, shift, release kill button, to allow Mag to fire, and resume
power I think an Electric Bike is a different deal, electric motors make max
torque at 0 RPM, minimizing need for gearing. The Electric Motor built in wheel
solves all but battery mount issues, sure looks cool.
 
I think I understand, you mean like an air shifter on a drag bike to cut power briefly as it shifts gear. No need, these boxes shift under power.
Hub motors are unsprung weight, that's the main issue. I also feel an electric motor would be better with gears. I could be wrong, We'll see...
 
I have no idea what you did there but it looks awesome. That is serious style.

I am a fan of the practical and reproduceable. I think you are really onto something.
 
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