Homemade shifter kit

[Sabotronics Inc.]

Hello!

My name is Hanzel, I'm from Costa Rica, and I would like to show you my project about a homemade shifter kit with double chainring crankset (one additional chainring on the left side for the engine chain). This is to find the way to ride my bike using the engine instead pedaling, keeping the gears for speed or strength with a low RPM


It isn't finished yet, but I'm just looking for details before I can complete it, I'll cut away the cranks and pedals, in other words, my bike will become something like a lightweight motorcycle.

Please, leave your coments about it, I'm waiting for your ideas, and just in case, sorry about my English!

Thanks a lot and God bless you!!!

 

[ocscully]

The drive as you show it in the photos above will not drive the crankset. The freehub body will just freewheel.

ocscully

 

[Elmo]

Instead of the hub you need a jackshaft.

 

[ocscully]

My Previons Statment Incorrect

All of the cogs shown in the third photo above (hub close-up) are mounted on the freehub body. there for they will just freewheel when power is applied. But I was wrong about them not driving the crankset! They will drive the crankset as shown in the photos above

ocscully

 

[NEAT TIMES]

Hanzel

Welcome To The Forum. You Have Us Thinking Now!! Lol. How Will You Start The Motor Without The Pedals? Push And Jump On, Like I Did 60 Yrs Ago?? Ron

 

[corgi1]

With a fixie(non-turning?) gear on both sides of the j-shaft hub, and the crank arms removed, as he says, the free-wheel would be on the rear wheel as in SBP shifter

 

[Russell]

NEAT tIMES,
I'm not sure but I think this pic represents what you are saying. If it is correct, it would be extremly hard to pedal start due to the hi pedal to motor ratio .

Hanzel

What If You Put The Pedal/crank Sprocket On The Right (standard Position). Then Flip You Freewheel Hub Over And Hook It Up The Same Way. The Freewheel Hooked To Your Pedal Sprocket. And One Of The Other Two To The Back Wheel And Derailier For Multi Speeds.

On The Engine Side Of Your Hub You Will Need A Large Sprocket To Get Your Needed Gear Ratio. Your Hub May Need To Be Locked.

Then You Could Pedal Start It And Pedal Assit When Needed. And The Freewheel Will Keep The Pedal`s From Turning When The Engine Is Working.

Don`t Have Any Experience With A Hub Like That. Keep Us Posted, Thanks. Ron .

 

[NEAT TIMES]

Russell

I Think That Is An Accurate Statement! By You, You Have It Right. My Bad, I Did Not Think It All The Way Thru. Ron

 

[Sabotronics Inc.]

Russell

It's a nice way, but in my desing I wont use rods and pedals, let me show you in this draw, I hope you'll understand my idea!

Don't worry about the start, I was thinking to make several modifications to a 3/8" ratch for this...

 

[Russell]

Yes I understand your setup. If you are going to use a 3/8 ratchet, I hope that it is removable. As it would not holdup as a prermanent kick start. Seems that a pull start would be the best way to go. However a home brew setup is always more fun.

Enjoy and have fun

Russell

Russell

It's a nice way, but in my desing I wont use rods and pedals, let me show you in this draw, I hope you'll understand my idea!

Don't worry about the start, I was thinking to make several modifications to a 3/8" ratch for this...

 

[moronic_kaos]

Ya know all that looks good and all (clutches and everything can always be flipped, changed, etc). But how are you going to get the derailleur to function properly when on the other side of the bike?

 

[TerrontheSnake]

Looks good hanzel, I think I like it better than the commercial version.

 

[KCvale]

I am in the process of installing a jackshaft kit from Sick Bike Parts LLC - Performance parts for your motorized bicycle is only $150.

The "kit" is simply a little box of metal parts like this.

Though the odd shaped flat plastic and metal parts are all custom parts, everything else is standard off the shelf components, with the "magic parts" being the right side pedal crank and ratcheting freewheel bearing.

On a normal bike the front sprocket is directly attached to the crank shaft along with the pedals, and the back hub has freewheel coaster so the wheel can spin without turning the pedals.

When you add a second front sprocket to drive the motor you don't want the pedals to spin too so the freewheel ratchet isolates the pedal cranks from the sprockets.

You just screw the Freewheel onto the special right side crank arm, and mount the sprockets on both sides of it like this.

Picture the two sprockets as a single socket and the crank arm as a ratchet wrench.
I can spin the sprockets in one direction by hand freely just like when you put a socket wrench on a nut and twist it as much as you can with your fingers, then turn the wrench handle the same way to tighten it down.

On this build I had to remove and replace the cartridge type crank shaft assembly with a standard 3-piece crank shaft system and used the kit included crank shaft and pedal cranks.

As you can see everything looks normal other than the crank shaft is a bit longer.

And this the freewheeling right crank installed.

This was the surprisingly easy part.
I put the whole thing together and in the bikes empty crank hole in an hour.

 

[Russell]

The derailleur is going to stay as original.

Ya know all that looks good and all (clutches and everything can always be flipped, changed, etc). But how are you going to get the derailleur to function properly when on the other side of the bike?

 

[Russell]

Hanzel,
I am also a home brew jack shaft guy. Here are a few photos.

 

[Sabotronics Inc.]

Hey guys, I'll be here as soon as I finish my project, don't worry!

 

[Sabotronics Inc.]

Finally, I got it!

 

[NEAT TIMES]

Sabo

That Is A Nice Bike. Looks Great. What Did You Wind Up Doing. Thanks For Sharing. Ron

 

[Sabotronics Inc.]

Well, here is my bike with a shifther kit (homemade in Costa Rica).

The gears work very well, the top speed is around 55 km/h full throttle (its a 48cc).

I'll be working in more details, an expansion chamber could be the next step, but I should wash the bike first!

I hope you'll like it!

 

[Pablo]

How do you start the engine?