Integrated motor mount and jack shaft

GoldenMotor.com

lukinhasb

New Member
Apr 23, 2011
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BR-13
That looks great!

I'll try to do one myself, I have some questions...

Here's a schematic drawing of what I understood about your project:



I want to know the following...

1 - How many teeths have the sprocket on engine axis?
2 - How many teeths have the sprocket #1/#2 and #3? (It's 18 and 10 teeths, right?)
3 - I would like to understand better this axis that holds the sprockets 1,2,3... What it was originally? A bike wheels's axis?

I want to understand so I can do it here...

- You've took the sprocket and fit it into a bearing
- Then you fit them into the axis, right? How did you lock them there?
- The bearings are suppose to "traction" to one side and let it loose if it tries to spin to the other side?

Erh, don't know what else to ask, but it's still not clear to me how I'm gonna make this you know, if you could try to explain it in a way I can do it myself here, I would really appreciate!

Thanks a lot!
 
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Tomasito

New Member
Apr 8, 2011
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Argentina
Let me answer some things i think i understood:

- The shaft (what you call axis -eixo-) is a common steel bar.
- The bearings are regular ones, they spin freely both ways.
- The sprokets 1 and 2 are from bicycle wheels (they're called freewheels), and they spin only one way (the #1 has to be fixed in order pedal-start the bike as usual, if you have a pullstart it doesn't matters)
- The sprockets locks in the shaft with a hex-bolt (allen).
- With some patience and a cup of coffe you can count the teeths from the pictures (well, not the one on the engine).

I answerd all that just by guessing by the way..

You are from brazil? I could maybe translate something, i know a little portuguese (just a little but it could help!).

PS: Russel, very nice work!!! I really liked, i think i'll make something like this too.
How did you managed the chain length in the engine-side? Half-links and luck? I'm only worried about that, everything else it's perfect!
 
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lukinhasb

New Member
Apr 23, 2011
8
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BR-13
@Tomasito

Thanks a lot for your good will, I think I'm starting to get it...

I have an question... The way it was assembled, when you accelerate, the pedals spin?

You can use the pedals with the motor without problems?

Also, Tomatito... If the bearings are regular and the sprockets that locks in a way and spins to the another, where these bearings go at? 'Cause the sprockets have it's bearings, right?

By what I could see, gears #1 and 2 have 18 teeths, and #3 something like 10?

And about the english, I can handle it with a little bit of patience rs... But thanks again!!

-- edit --

Also, how did you weld this shaft on the frame, if it was suppose to spin? o.o
I'm thinking on using an bike wheel's shaft
 
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Russell

Well-Known Member
Apr 19, 2009
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Sprocket #1 is 18T (14T would be better). #1 should not be a freewheel, I welded it so it would be a standard sprocket.

Sprocket #2 must be a standard bicycle freewheel. This will prevent the pedals from turning while under motor power.

Sprocket #3 is a 10T (#41 sprocket with teeth cut thin to accept standard bicycle chain).

The motor mount is slotted for adjustment of the chain tension of sprocket #2(going to the chainring).

Sprocket #3 needs only the derailure for tension.

Sprocket #1: The bearing housing was welded in place with the chain installed. Due to it's short length, chain stretch is minimal. However I did later install a u-bolt to slightly flex bearing mount to take up the (minimal stretch).

I have many, many miles on this system and it functions well.
 

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Russell

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Apr 19, 2009
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This system cannot be bump started, in an emergency it can be pedal started(but not easily). A pull starter is required.
I have other post here on how to modify the pull starter to make it more dependable.
 

lukinhasb

New Member
Apr 23, 2011
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BR-13
Ok so, I'll mount it in a 24" bike, so I don't have space for it in the frame..

So I'm doing it in the baggage stuff (don't know the name for it in english), it would be something like this:



As you can see in image #4, the engine would weight to one side, disbalancing the bike, but I can't do different 'cause the chain has to be straight... And if I stretch jackshaft to fit the engine in the center of the bike, I wouldn't be able to pedal 'cause it would hit the shaft, you got it?

I will be using a 2.8 HP 4 strokes engine with 87cc, does it can handle well the bike? It this engine + jackshaft I would probably be able to climb some hills without problem?

So, any ideas to the project would be awesome, I'll take some pictures of my bike later... I'll format my computer now *-*

Thanks .weld. :]
 

Russell

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Apr 19, 2009
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This is starting to look like a project that should use a Sick Bike Parts shift kit(HD).
I have no experience with rack mounts.

I doubt that the motor being offset would be felt much while riding. Of course the center of gravity will be much higher as with all rack mounts.


My design was for a s-ray bike only.
 
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lukinhasb

New Member
Apr 23, 2011
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BR-13
I'm Brazilian, I would pay like 100% taxes plus 1~2 months 'til shipping, so I have to do one for my own...

I'll open a new topic so I don't offtopic yours, if you could support it I would be glad.

Thanks for your time so far!
 

35 PROG

New Member
Feb 3, 2012
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1
iowa
This system cannot be bump started, in an emergency it can be pedal started(but not easily). A pull starter is required.
I have other post here on how to modify the pull starter to make it more dependable.


Russell I am not seeing why this system cannot be bump started? If the free wheel 1 is welded. Is it due to the derailer? What am I missing? this is the cleanest set up I've seen, and I have decided to use a jackshaft setup like yours, however, I need to be able to bump start it. Could you please me understand what I need to do to get the 5 speed with jackshaft and still have the ability to bump it.

Thanks Shawn.
 

35 PROG

New Member
Feb 3, 2012
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iowa
Russell, Boy oh boy,, That is so obvious now! I am really showing my newb status. Could a guy weld the freewheel assy so that it could still bump start? Or would the compression or "engine brake effect" cause it to try and unscrew from the rim? Do you know of a method to make rear sprocket a solid mount? Possibly a hub mounted bracket? Would you recommend attempting this? I would assume that you prefer a pull start method. Is this the reason?

thanks so much for helping me understand before spending $$$$.
 

Russell

Well-Known Member
Apr 19, 2009
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Actually it took a while before the cobwebs cleared, then it dawned on me(freewheel cluster)!
I (think) that if the hub & cluster threads were properly cleaned and you used permenant lock-tight it woul take the load of starting.

However The derailure will not allow bump starting. That is why I said it can be started with the pedal (in an emergency) but it is not easy.

I did modify the pull start to make it more reliable(posted elsewhere). I also carried a spare pull start in my road kit(just in case).

I rode that bike for a few years and it was great! (climb ANY hill in low and go way to fast in high). You have to get used to down shifting when comming to a light.

Well have fun!

Jim English(Russell)
 
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Crazy Horse

Dealer
Feb 20, 2009
1,153
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USA
I was looking for an easy way to mount a DIY jack shaft.
This is what I ended up with.
Jim, this is awesome, amazing talent you've demonstrated with this design, and thanks for sharing the plans with us Pedal Chopper Builders.

can someone make me one and ship it??

flybytaco, did you get yours?


Sprocket #1 is 18T (14T would be better). #1 should not be a freewheel, I welded it so it would be a standard sprocket.

Sprocket #2 must be a standard bicycle freewheel. This will prevent the pedals from turning while under motor power.

Sprocket #3 is a 10T (#41 sprocket with teeth cut thin to accept standard bicycle chain).

The motor mount is slotted for adjustment of the chain tension of sprocket #2(going to the chainring).

Sprocket #3 needs only the derailleur for tension.

Sprocket #1: The bearing housing was welded in place with the chain installed. Due to it's short length, chain stretch is minimal. However I did later install a u-bolt to slightly flex bearing mount to take up the (minimal stretch).

I have many, many miles on this system and it functions well.
Jim, I love this jackshaft setup, and am hoping you'll see my PM, and give me the answer I'm hoping for dance1.

C.H.
P.S. Pedalchopper builders using the above jackshaft system designed by Jim aka forum member " Russell " with the 5-speed rear hub is IMO the best way to enjoy a Pedalchopper style motorized bicycle build!