Ebike project

[Sahbin]

First of all hi to everyone. I am new to electronics and I want to do a rather complicated project for fun and I am trusting on your help

Everything is for now only plans for future. What I want to do is of course convert a bike to an electric one but I want to do it a little bit different. I uploaded an image read the instructions and tell me if its possible to do thank you.

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[Sahbin]

No one can help ?

 

[Reloadron]

Can it be done? Yes. Unfortunately the image does not show very much. There is the consideration of the motor to be used, the power supply (battery), the control system for the motor and a host of other variables to be considered. Oh yeah, the bike has no handle bar for steering.

Ron

 

[SABorn]

I take it that what the OP is wanting to do here is a automatic/electrical controlled derailer system for a standard push bike chain gearing system. (that sounds confusing dont it)

Guess it could be done with some sort of little worm drive motor to move the derailer arm as a cable control would normally.

Although its all adding weight to a system that power to weight ratio is very important to consider.

Pete.

 

[Reloadron]

I take it that what the OP is wanting to do here is a automatic/electrical controlled derailer system for a standard push bike chain gearing system. (that sounds confusing dont it)

Guess it could be done with some sort of little worm drive motor to move the derailer arm as a cable control would normally.

Although its all adding weight to a system that power to weight ratio is very important to consider.

Pete.

Hi Ya Pete

Based on the original post and linked to cartoon I must admit I don't really understand where the OP is wanting to go with this. Automatic transmission?

Flashback memories of the "English Racer" long before 10 Speed bikes came on the scene.

Ron

 

[Sahbin]

Well the point is beeing able to "program" motors or servos to operate automatically at a precise time.

 

[Reloadron]

Well the point is beeing able to "program" motors or servos to operate automatically at a precise time.

That can be done. Much the way an ECU (Engine Control Unit) monitors sensor inputs and makes decisions as to when an engine should respond certain ways or how an automatic transmission (of today) works. If this is something you want to get into you should maybe start simple. Possibly start with a little robotics and how the decision making process works in a simple robot. Then worry about more advanced features. It would serve you well to get familiar with micro controllers and their programming. The forums have a section devoted to them. You decide exactly what you want something to do and work out the mechanics of the hardware, motors, solenoids etc.

Ron

 

[Sahbin]

Thanks Ron very helpfull

 

[gary350]

This is the best way to do this. Replace the front wheel with a back wheel so you can put the electric motor on the front and still use the pedals and bike brakes. The human boby is 1/4 hp for a good strong healty bike rider so you need a 1/4HP DC motor. Use the largest bike you can 27" or 700C wheels. Gear the bike to go about 15 mph or 18 mph top speed. Do the math to calculate the gear ratio from the motor to the front wheel. You will probably have to make your own front sprocket for the wheel but that is easy. Use single speed chain so you can use 1/8" aluminum plate for the large sprocket. Calculate the number of teeth needed for the motor to turn the front wheel at 15 mph. Center punch the center of the aluminum plate then scribe the Circumference for the center line of the teeth. Center punch each hole location for each tooth and drill it with a small 3/32" drill to start. Next drill the holes 3/16" then 1/4" then 5/16" etc. Use a hand jig saw to cut off the extra metal above the teeth. Hand file to fit the chain. Drill the center hole to fit the wheel. Connect a variable speed drive from the battery to the motor. This has been done and it works great. I could send you some photos but it will take me a while to find them. I have some photos of my 72 teeth sprockets that I made. I made 3 of these.

If you use multi speed chain on the front you will have to use thinner aluminum for the sprocket if the sprocket is large the thin aluminum may not be strong enough that is why I suggested standard single speed bike chain it is wide enough for 1/8" aluminum plate. You can buy aluminum plate at your local machine shop. Lowe's, Home Depot, Hardware stores have OVER PRICED aluminum plate too.

Here is the photo of my 72t sprocket. The smaller sprocket is a standard 52t factory make sprocket.

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If you put that motor on this bike it will do 30 mph. Wind resistance is 2/3 less than an upright bike.

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Crusing along at 32 mph.

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[Sahbin]

That was a great help thank you very much