Thoughts on Lifan 4HP 118cc engine?

[mattrgray]

Mine works.

Well thats good to know, thank you. 8 speed?

 

[Frankenstein]

Well thats good to know, thank you. 8 speed?

About an infinite number of 'speeds,' actually...

No I'm not being smart, I have a nuvinci hub which is a cvt, so by definition I have an 'infinite' number since it's every possible combination between a lower and upper limit ratio.

The better way to look at these is as a spectrum of gears you can move between, a nuvinci 360 for example covers a 180% change in both directions from the input gear tooth count. So my 22 on the rear can cover an infinite set of gears between about a 39 (lowest) and a 12 (highest.)

I hear they make some tough actual geared internals but I look at what these motors do to plain cassettes, they eat through them, there are some gems that outlast the bunch, nuvinci and whatever KCvale uses are notable. They make a 380 now so a 22 could cover about 2 more teeth in both directions.

 

[mattrgray]

About an infinite number of 'speeds,' actually...

No I'm not being smart, I have a nuvinci hub which is a cvt, so by definition I have an 'infinite' number since it's every possible combination between a lower and upper limit ratio.

The better way to look at these is as a spectrum of gears you can move between, a nuvinci 360 for example covers a 180% change in both directions from the input gear tooth count. So my 22 on the rear can cover an infinite set of gears between about a 39 (lowest) and a 12 (highest.)

I hear they make some tough actual geared internals but I look at what these motors do to plain cassettes, they eat through them, there are some gems that outlast the bunch, nuvinci and whatever KCvale uses are notable. They make a 380 now so a 22 could cover about 2 more teeth in both directions.

Very neat, never heard of those before im thinking about the old 3 speeds and newer 8 speed ones. If you could find a guy who makes or would make the cassette free hub but solid, so you could wouldn't have the free wheeling and you could bump start the engine I think that would be a nice touch.

 

[Frankenstein]

Very neat, never heard of those before im thinking about the old 3 speeds and newer 8 speed ones. If you could find a guy who makes or would make the cassette free hub but solid, so you could wouldn't have the free wheeling and you could bump start the engine I think that would be a nice touch.

You couldn't bump with a cassette regardless if you use a derailleur, the design isn't workable at pulling in reverse from the bottom length of the chain, when you do that it yanks the derailleur all up and then the slack on the top rolls under the sprocket and even the chain itself and then no more bikey...

Foggiest clue if the radial gearing in an internal would push forward for bump starts but it might, and that might work better since there's no slack involved regarding chains. A nuvinci certainly can do it since the principal behind it has nothing to do with actual gears, and when spinning parts by hand I recognize it can operate in both directions. I know that a bike with internal gearing and a locked freewheel is a solid tranny right up to the manual clutch, so using a lower gear than the speed calls for with make the engine behave as a Jake brake.

I could lock my hub up and make it direct connect to the bullet train engine I'm going to get running and not have a problem because they included a one way clutch between the gear and clutch so I wouldn't have an engine braking issue.

 

[Randall]

I have put my eyeballs on that Lifan engine. Very affordable and looks user friendly. And I think it has a 4 speed tranny.

You are really jumping into another world with that, effectively building a 125cc motorcycle. I think an engine like that would really require a 3D frame. Besides, I really wouldn't trust a bicycle frame and wheels to handle that kind of power and speed.

And you would have to plate it, have a motorcycle endorsement and insurance.

I don't know timbone, this guy did it pretty successfully:



I am planning on doing the same with this frame: http://www.bicycledesigner.com/bike-parts/bicycle-frames/stretch-cruiser-z2-tank-red.html and this engine: http://www.ebay.com/itm/4-UP-LIFAN-...m5882c9c6b4:m:maFrQENxRv07o79PMaq8cJg&vxp=mtr

 

[mattrgray]

I don't know timbone, this guy did it pretty successfully:



I am planning on doing the same with this frame: http://www.bicycledesigner.com/bike-parts/bicycle-frames/stretch-cruiser-z2-tank-red.html and this engine: http://www.ebay.com/itm/4-UP-LIFAN-...m5882c9c6b4:m:maFrQENxRv07o79PMaq8cJg&vxp=mtr

looks nice, would love to see it. The few motorized bike videos with this 125cc engine seem to be the semi automatic trans engine, havn't seen one with the manual. good luck!

 

[Randall]

looks nice, would love to see it. The few motorized bike videos with this 125cc engine seem to be the semi automatic trans engine, havn't seen one with the manual. good luck!

It will be interesting.

 

[Timbone]

I don't know timbone, this guy did it pretty successfully:



I am planning on doing the same with this frame: http://www.bicycledesigner.com/bike-parts/bicycle-frames/stretch-cruiser-z2-tank-red.html and this engine: http://www.ebay.com/itm/4-UP-LIFAN-...m5882c9c6b4:m:maFrQENxRv07o79PMaq8cJg&vxp=mtr

Very cool! So that motor can be secured in a 2d frame. Wondered about that.

But it is a motorcycle. Kickstart and gears. The guy did say he had it plated. It should be played as a motorcycle.

Also: I would not trust an average bicycle wheel with a 3/8" axle to push me around at 60mph!

 

[Randall]

Very cool! So that motor can be secured in a 2d frame. Wondered about that.

But it is a motorcycle. Kickstart and gears. The guy did say he had it plated. It should be played as a motorcycle.

Also: I would not trust an average bicycle wheel with a 3/8" axle to push me around at 60mph!

I agree. I'm going to have to find a beefier rear wheel. I have those solid mag wheels from the other build but not sure how much they can take.

 

[bakaneko]

I agree. I'm going to have to find a beefier rear wheel. I have those solid mag wheels from the other build but not sure how much they can take.

you know the funny thing is that if you take this engine 125cc lifan semi-auto ($400) and compare it against 212cc predator engine, gear reduction box, jack shaft, free wheel. i think the lifan is only a bit more expensive to have a multi-gear drive. the only issue is mounting and getting to the shifter. your frame is perfect but for a normal bike you will need to make a lever shifter . will u register as a moped?