Electric Bike

[Sal Paradise]

I just finished the first phase of this project. I wanted to build an electric bike for a while but I wanted to do it from scratch or as a hack . I could have just bought a $400 hub motor . The other day at the dump I spotted a Razor E350 Electric dirtbike

And so my 15 year old son and I have been taking it apart and attaching the drivetrain to a Panasonic Sport 500 bicycle. I have $30 bucks in the project to date but a lot of hours. The hard part has been keeping the existing bike pedals and chain free, reversing the Razor Drivetrain and freewheel and attaching to the left side of the bicycle. I wanted to have full normal bicycle function and no drag from the motor when its not in use.

Here is a video of it in action, V1.O. http://www.youtube.com/watch?v=X0CNC_sBTCY&list=HL1321134122&feature=mh_lolz

The tiny RC lip batteries I have taped onto it did a good job but they are waay too small. Next up is a real battery and for that I have basically my whole budget. I will buy a $75 chinese lipo battery that should make the bike fly and give it a 10 mile range. I also will need to upsize all my wires for this as they were getting warm. This is a learning process.
Eventually I want to take a full suspension disk brake dirt bike and install a big electric motor , like 1500 watts 48v - sort of a stealth dirtbike thats invisible to the authorities.

 

[sweatmachine]

Cool project, Sal. Thanks for keeping us posted.

 

[Sal Paradise]

Pugsly

Thanks Jeff. There are guys building decent 50 mph bikes, problem is it costs money. This thread - ebikes shows a lot of whats going on with home built bikes.

There is a lot of experimentation going on, its a new thing - must be similar to what the early motorcycle builders went through. After all, they started with bicycles too.
This one claims 113 km.hr

 

[thearcticsea]

I'd love to build an electric bicycle to commute to and from work for $0. Too bad I know nothing about the process.

 

[Sal Paradise]

me too . The problem is money. Controller, lipo batteries, hub motors. Its $2000 easy for the good stuff.

 

[Sal Paradise]

New developments

I am slowly moving into this hobby. My cheap junkyard refugee ebike is slowly making progress. We now have the 13 Amp 36 volt chinese lipo and the controller and twist throttle out of the scooter. Unfortunately , the range is more like 3 miles on the level or 1.5 on a grade. I will add in one more 12v lipo, you just solder them in series and at 48V 17 amps that should be enough. Probably too much for the motor. Money is the hold back to improving this bike.

Sal-ebike

and state of the art . By way of comarison. I am 36v and probably pulling 25 amps. They are at 112v and can pull 400 amps. Then they go on fire, but its impressive.

http://www.youtube.com/watch?v=Sk_bmSRog-c&feature=player_embedded

very similar dyno process to custom motorcycles. Well, sort of.. I saw 126 foot lbs of torque for a second before it caught fire.

http://www.youtube.com/watch?v=e03rMDmJzLE&feature=related

 

[koifarm]

Looks like a fun project Sal, I had no idea there were these kind of bikes in production.....I'd compare them to the same thing in aviation, going from standard light aircraft to Ultralights to hang gliders to square parachutes with a fan on their back.
It looks like fun and shucks, as long as you don't have buckets of money tied up in it, it's a good way for you and the kids to play with it....
Of course, now that you're hooked....there goes the budget....lmao.....

 

[Kirkus51]

I have a friend who has an electronically assisted bike. Evidently it really pisses off the hard core bike riders when he's heading uphill. Like me he has bad knees, hips, back and shoulders.

Nice video!

 

[Sal Paradise]

I suspect there is almost no crossover between the two types of bicycle groups. The competitive cyclists are jocks, the ebike guys are hackers, geeks and hot rodders. The spandex guys hate ebikes. Even when I bring my little ebike out on the railtrail , the spandex cyclists completely ignore it. I predict someone will get passed one day and a fight will break out. Its gonna happen.

 

[Sal Paradise]

Another observation. The ebike is apparently invisible and by that I mean I go everywhere and anywhere a regular bike goes, but without pedaling . My ebike is obviously built on a ten speed. Its silent , it has no lights or reg. plate. Police and civilians alike just don't notice it. Which is pretty cool. Nobody asks about it. It goes a little bit faster than your average person can pedal, except for spandex clad wannabe olymmpians. Maybe 20 mph.

 

[sweatmachine]

That's pretty cool, Sal. I see a lot of bikes with small 2-stroke motors around Austin, and they are anything but silent. They are neat, but really noisy. That stealth bike of yours sounds great.

 

[koifarm]

Idly wondering if anything like a two wheel drive would be a good thing?....only problem I see is battery power but there might be a way around that.

 

[Sal Paradise]

One of these days, when the weather is nice I will put up an onboard video. Technically anything is possible. I am sure I could build a 45 mph stealth dual sport. Probably with something like a 30 mile range. The only real problem is money. It would be 2 grand to do that right.

 

[Sal Paradise]

The first bike was so successful that I threw together this little commuter bike out of an old Trek and some scooter parts. The Trek has 80 psi kevlar tires, alloy rims and cantilever brakes. With its upright handlebars its a better townie than the 10 speed and better for the twist grip throttle I put on. The throttle also has a volmeter indicator light which works.

I wanted it to look good and also didn't want my expensive batteries and electrics stolen. The satchel is leather($5 at a yard sale) and besides the batteries and electronics also has my lunch and water bottle in it. Unplug and take it inside with me. The bike has 24 AH lithium batteries which I mail ordered from China for half the price and soldered up myself.

 

[B06Tang]

I know it is off the subject but is your son into downhilling? That is one sweet Giant you have there. I am going to be bringing a Rocky Mountain RM9 with me. Where are the downhill courses at?

 

[Sal Paradise]

Hmm.... are you looking at the right bike? I see a Trek with a rigid fork. And with the skins on it, I wouldn't want to take it off road.

 

[B06Tang]

ooops...sorry about that. You were using that Giant as an example. It is amazing what happens when I read a little bit along with looking at the photo:nut::shrug:

 

[innominate]

A little off topic. Saw this electric bike during our mod vs rocker rally this past weekend. It would make a nice commuter.

 

[Sal Paradise]

Very cool inominate.Notice the huge rear sprocket for the toothed belt. Yeah Zero Cycles is making a run at it. They had a huge booth at the motorcycle show. I hope they are successful.

 

[hankmarx]

That bike was weird when it whipped past you with no noise. It did look like fun!