Has anyone ever seen or built a truly pedal-able motorized bike?

[frascati]

I'm asking about a petrol motorized bike. When the engine is shut off or disengaged you can pedal freely as if it were a bike. In other words there is no engagement of the motor's gear/belt reduction while pedaling.

Does it exist? A petrol powered bicycle that you can pedal without any engagement of the motor or motor's gear/belt reduction. When not using the motor you are able to pedal freely. Friction driving the tire is an answer, but does not count.

Friction driving the tire does not count.

 

[robe]

No, haven't seen one yet.
I can visualize the drive sprocket attached to a bearing on the axle. The tricky part would be some kind of cogs that could engage and disengage the sprocket from the hub.

Maybe a magnet.

 

[GW's Motorized]

It would have to have a 1 way bearing at the axle on the drive side. Maybe a shift kit setup would allow for a 1 way bearing at the jackshaft and that would be easier than one on the axle. The only problem is you couldn't pedal start it, and the pull start setups break way to easy.

 

[robe]

I believe he was asking about a truly free wheeling set up. With the jack shaft free wheel set up the chain to the hub would still have to spin.

Now that you mention it a sprocket attached to free wheel would work but that is what I was thinking about in a round about way.

 

[Risk Man]

I'm asking about a petrol motorized bike. When the engine is shut off or disengaged you can pedal freely as if it were a bike. In other words there is no engagement of the motor's gear/belt reduction while pedaling.

Does it exist? A petrol powered bicycle that you can pedal without any engagement of the motor or motor's gear/belt reduction. When not using the motor you are able to pedal freely. Friction driving the tire is an answer, but does not count.

Friction driving the tire does not count.

Just pull in the clutch and pedal the bike.. not sure what the mystery is here? Yes, the sprocket turns, but there is minimal resistance pedaling with the clutch disengaged.

That said, my MOTOPED with the patented Jackshaft, is totally disengaged from the engine while pedaling. The only issue is the gear ratio is such that it is like pedaling a 21 speed bike in first gear.

 

[robe]

Just pull in the clutch and pedal the bike.. not sure what the mystery is here?

Works for me but I have lots of low gears. I am not interested in adding yet another point of failure to loose a bit of resistance spinning the chain and clutch gear.

 

[Sidewinder Jerry]

Yes it has been done and I did it.

The triple chainring Staton Inc shift kit uses a double freewheel system. So unlike single freewheel shift kit systems the engine drive chain doesn't move when only using the pedals. If using human power only my bike could also be rode like a 3×7 drive system

 

[Sidewinder Jerry]

It would have to have a 1 way bearing at the axle on the drive side. Maybe a shift kit setup would allow for a 1 way bearing at the jackshaft and that would be easier than one on the axle. The only problem is you couldn't pedal start it, and the pull start setups break way to easy.

I don't think the thread was limited to just 2 stroke bump start engines.

 

[Will'smotobikes19]

I think the original poster should know with automatic centrifugal clutches you can pedal up to a certain speed then you use the motor. Doesn't matter if it's friction drive, belt or chain. For the bump start cg engines you have to pedal or spin the wheel on a stand. So yes all you do is pull the clutchand pedal.

 

[Sidewinder Jerry]

I think the original poster should know with automatic centrifugal clutches you can pedal up to a certain speed then you use the motor. Doesn't matter if it's friction drive, belt or chain. For the bump start cg engines you have to pedal or spin the wheel on a stand. So yes all you do is pull the clutchand pedal.

The OP asked if there was a system where nothing connected to the engine moved. Even with most centrifugal clutch/CVT/reduction box drive systems there's still moving parts connected to the engine. Things like the drive chain, internal belts and bell housing on the clutch.

On my bike if the engine isn't being used no part of the engine drive system beyond the shift kit is moving.