Electric Razor Motors

grouchyolfart

New Member
May 31, 2008
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Wahiawa, Hawai'i
Just saw a Razor Mini Chopper on our local Craigslist selling for $125.
Looks like a chain drive and is mounted to the bottom
of the seat stem along with what looks like 2 battery packs
and appears to be chain drive.
Razor Mini Chopper

Wondering if anyone has tried mounting one of their motors and
battery packs to a regular bicycle and what kind of speeds didja
get? I know it won't be fast, but would be nice if it's enough to
help get me up a couple of hills. Can't go wrong with the price as the
thing can be cannabilized for everything including the controller.

Whoa, a revelation. Mount it on the seat stem and run the drive
chain to the crank set. Maybe? Yes. I realize I'll need a free wheeling gear. ;)
 
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deacon

minor bike philosopher
Jan 15, 2008
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north carolina
I use that kind of engine to build friction drive bikes. These days I chain drive the roller so that the motor can be mounted directly over the wheel as opposed to off to the side as I used to do with dirce drive on the motor.

With the friction drive the motors will help you up a hill at about the pedal speed on the flats. To save on battery I usually just let it coast or pedal it a little on the flats or downhill. I call my current configuration pp/e bike (people power electric assist bike)

With a bike you really do not need the controller at all. A simple on off switch will work just fine.
 

grouchyolfart

New Member
May 31, 2008
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Wahiawa, Hawai'i
Mahalo Deacon! Hey, just like you, these things seem to come up for sale when I'm short on cash/not ready or disappear when I do have the cash and time. :D

I only need the help up a couple short but fairly steep hills on a 4 mile round trip ride. I'm not racing so I cruise the flats at a gear that barely gets tension on the pedals..rd. If I gotta detour, it takes the ride up 8 to 10 miles on the homebound stretch with one really good hill to climb. Don't need a mega battery for my commute, but I'll probably upgrade to a couple of scooter batteries. Should have enough power to last up to 15/20 miles if I'm really lazy. :p I'll make sure to put a few bucks aside after our tax return and hope another comes up for sale when I'm ready. ;)
 

deacon

minor bike philosopher
Jan 15, 2008
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You can almost always find a 250 - 350 watt motor on ebay for about thirty bucks.... Add a household extension cord and wall switch to your bike and then with a home made drive wheel you are ready to go. For what you want the friction drive will be plenty. It's how I plan to use my bike when I get to ride again. Pedal it most of the time for the exercise, then kick in the motor on the nasty hills so that I can pedal up them as if I was on flat ground.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
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Just to put an exclamation point on the ebay thing, I am bidding on a motor for my suspension bike. The used motor should go for about twenty bucks delivered. At least the last one did. I already have the mount built and am waiting for a sprocket from tnc for it.

I used two 4" L brackets for the motor frame. Those and the misc nuts and bolts would come to price under $3.. I have a couple of drop down holders for the axle made from scraps.

I have half of a one foot 5/16 rod as the axle. It and the nuts and bolts for it would come to under $1.60 including tax. I bought eight skateboard bearing for 4.50 on ebay including shipping. I used two of them on this build approx $1.25. I have a few pieces of #25 chain from scrapped scooters and I think I bought a piece or two. The bit i used probably has a value of $5 or less. It will need a hinge and a spring and bit of chain for tension. The hinge might be three or four bucks I have lots of them laying around from other failed builds so I won't be buying one for this build. Same with the spring, the six inches of chain is about $.50... You will need an extension cord under $2 and a household wall switch about another buck.



Your drive wheel can be anything from caster wheels, to toy car wheels. they say skateboard wheels are good. I have one of those on my other bike. this one I'm going to try caster wheels but that might change after the test ride. They are smaller in diameter than the skateboard wheel.

Say I have $20 in the motor and another $20 roughly in the drive wheel and mount then I have about forty bucks in the drive not counting the cost of batteries and a home made battery holder.

the battery holder was made from long "L" braces they sell at home depot. I see them mostly as corners in shelving units for warehouse applications. Anything like that would do to make a luggage type rack to go over the rear wheel. My other bike has a coaster brake rear wheel so I mounted it to the brake mount hole.

The suspension does not so I mounted the batter holder to the seat post. Ran two of the angles about 18" long over the tire, then braced them with a piece of chain link fence tension bar. You can build a couple of things from a single piece of items so I count them at half value or about $10 for the battery rack.

that makes the bike about $50s without the batteries. There is very little likelihood that a battery from a used scooter will be any good since they were probably stored without being charged and have pretty much been screwed up. At least that has been my experience.

I did buy two new 12ah batteries for $60 bucks delivered. So you can build your own friction drive bike for just a little over a hundred bucks.

This drive is not going to do much more than cut the pedal up hill from a grind to pedaling like you are on flat ground. Unlike the chain and hub drives there is a loss of power in the friction design. I like it because it is interchangeable and cheap to make. I'm not all that mechanical you know.

They are also very low maintenance except for the battery thing. I use a 12 volt battery float charger. I rotate it between the batteries. It seems to work okay.

This is the guts for the pp&e bike design.....



If you look real close you will see the top of the strap hinge with a bolt it is to lock the engine off the tire for the bike trails and to move around in the shop. there is also a brake handle and cable to lift the engine while riding to cut down on the drag while coasting, or pedaling.
 
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deacon

minor bike philosopher
Jan 15, 2008
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north carolina
I should have added that the cool battery case was made for me by comfortable shoes.... Shoes also made the tool pouch that you can't see.

The batteries are held down with a cheap bungee cord.
 
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grouchyolfart

New Member
May 31, 2008
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Wahiawa, Hawai'i
Hoi Deacon, thanks for the detailed pics. :) They help more than you will know and clears up a whole bunch of mounting questions. (^) I can find most of the mounting hardware at our local Ace or just up the street behind a supermarket. I already have an old commercial rear rack and recently bought a heavy duty nylon bag that mounts to it. It'll be perfect for the batteries and I can still use a couple of cheapy Walmart mini backpacks as panniers that'll mount under this bag for lugging my stuff or go the other way around to lower the center of gravity.

Gonna get busy with Craigslist as I have a couple of 50cc scooters the wife wants me to get rid of. :oops: Should bring in plenty enough for all the parts I'll need. I'll still have one to use for those rainy days, which isn't too often out here. Mostly "tourist" weather and perfect for cruising on a bike to get to work. .elec.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
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north carolina
I wish I could say the same. I tested the bike in the picture again today. It is 40 degrees and cloudy. The best thing about this bike is that it goes slow enough that there is not a 20 mile an hour wind in your face. more like 10 to 12... I need to adjust the tension on mine to make it run stronger.

Also I have 3 smaller caster wheels on the new build. I am going to wrap them with some heavy duty sandpaper for grip. I need to finish that build and test it. The rpms are much less on the ebike than on the WW so the sandpaper might do pretty well on it.

This kind of design has the features I personally wanted,. Engine lock up and lift but also it is just enough help to pull the hill or if I am just lazy. I think it would do better on a mountain or road bike so that it has the gears to maximize the PP part of the equation.

I dieted and lost about 50+ pounds last year. Since I haven't ridden in a while I have gained about five of it back. I am looking forward to riding this motor up on the bike trail and drop the engine to get home only about half a mile but mostly up hill.
 
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Bobocop

New Member
Jan 6, 2009
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Toronto
With a bike you really do not need the controller at all. A simple on off switch will work just fine.
You keep saying this to everyone, I don't know why.

An alectric motor draws the most amps from the batteries when it's first turn on, if you use a switch (which is fine if you want to go the cheap way) It draws a lot of amps from the battery every time you push the switch which in turn drains the batteries quick,
because there is load (your weight and the bike) and the motor needs time to carry that load and pick up speed to its normal operating rpm's.
while it's doing that it is draining your batteries Drawing a lot of amps.

If you use a controller you can control the amps that the motor draws and the speed.

so why you keep misleading people about this and telling them that a controler does nothing is beyond me.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
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north carolina
Because I have done it both ways and the controller did minimal to zero good. When you start a scooter you are pulling max amps because the scooter is at a dead stop. You are overcoming the inertia of the scooter and your body weight. So to move it you have to pull max amps even with a controller I would think.

When you turn the motor on a bike, you should already be moving. The inertia is being overcome by the pedals thrust of the bike. I never turn my motor on until the bike is moving at a pretty good clip. It is a friction bike so the motor would be almost useless at low rpms. That has also been my experience. With the simple on and off switch you would also do your low speed movement through the parking lot ect with the bikes pedals not the motor.

I'm sorry that is what my experience has been. I actually did test the battery range using both and found no significant difference. I have two controllers, if there was a significant difference I would definitely use them and the throttle. There just isn't in my opinion.

If you think the controller on a BICYCLE does you some good saving your batteries fine... I don't happen to believe that it does any good at all on the friction drive helper engine I build. I just can't see the advantage to buying something that does little to no good. Maybe on a hub motor where you plan to start the engine to pull you from zero it might help. Since I never owned one of those I have no idea.

If it will make you happier, I will be more than happy to state, IN MY OPINION AFTER MONTHS OF TESTING the controller does no good on my kind of build. Is that better? Trust me if I had not tested it in real world conditions on the bikes I have built I WOULD not say what I say.



I am always glad to hear someone else's opinion though.
 
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comfortableshoes

New Member
Jul 22, 2008
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Beverly, MA USA
You keep saying this to everyone, I don't know why.

An alectric motor draws the most amps from the batteries when it's first turn on, if you use a switch (which is fine if you want to go the cheap way) It draws a lot of amps from the battery every time you push the switch which in turn drains the batteries quick,
because there is load (your weight and the bike) and the motor needs time to carry that load and pick up speed to its normal operating rpm's.
while it's doing that it is draining your batteries Drawing a lot of amps.

If you use a controller you can control the amps that the motor draws and the speed.

so why you keep misleading people about this and telling them that a controler does nothing is beyond me.
Whoa! Everyone is entitled to their opinion here, Deacon doesn't like controllers, they do nothing him. You have to keep in mind you can't really start a friction drive like Deacon is building from stop- you have to be moving before it is engaged- that goes for gas or electric... Hence his opinion that the controller does nothing for him. It's also based on his experience in ilding these bikes and how he uses them.

To each their own. Opinions are like @$$holes; we all have one and some of use have have a larger than one than others....
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
237
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up north now
If you kick on the motor after you are rolling, a switch is all you need.

I suggested to deacon waaay back that maybe a controller was needed, and he spent his money and found after a lot of EMPIRICAL TESTING, that I had wasted his money.

Sorry about that one deacon....