building an electric pit bike, where to start...... I have the rolling chassis.

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cajunjay
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building an electric pit bike, where to start...... I have the rolling chassis.

Hi

Im glad I found this forum and im so impressed with the projects and vehicles the members here have managed to build. Im no mechanic but im pretty sure with some help i can get my lttle dirt bike running one day.

I just need some pointers as to what i need, motor type, batteries and speed control etc. I really wanna get a pretty decent range for racing about the fields and i feel speeds of 35mph+ will be sufficient for a first project.

Please point me in the right directions I will probably be buying most of the componants from somewhere cheap like ebay.

Thanks in advance

cajunjay
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Re: building an electric pit bike, where to start...... I have t

I need some help with what motors will be sufficent for speeds upto around 35mph and good batteries plz help im desperate waited weeks but not a single reply.

But I have got the rolling chassis and around $500 at the moment

jdh2550_1
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Re: building an electric pit bike, where to start...... I have t

Hi cajunjay,

A hub motor such as the one sold by Electric Motorsports would probably be good enough. You'll need to look at the RPM per volts and calculate what voltage to run it at to get the wheel speed you need for 35mph. You could also look at other motors in the 1.0 to 1.5 hp continuous rating range that have high rpms (I'm about to convert my lawnmower using a Techumseh A90000 which has 1.5hp & 3200 rpm - not sure of the torque characteristics though (probably not enough for your needs plus it's got a weird housing - good for lawnmowers bad for you)).

If it's a pit bike then I'm guessing a range of 10 to 15 miles per charge would be sufficient? If so, then batteries shouldn't be too difficult to choose. It will depend a lot on voltage and on space on your chassis.

Does that get you started? If not then ask some more specific questions and I'm sure you'll get a few more replies.

John H.
Blue XM-2000
Ann Arbor, MI
http://www.revevllc.com

John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas.

marcus
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Re: building an electric pit bike, where to start...... I have t

hi cajunjoe,
1st. John, I did'nt see hub motors on that site. can you repost that link for me too.
2nd. Joe here is a couple more links.
for smaller stuff like bicycles and scooters:

http://www.electricscooterparts.com

bigger stuff:

http://www.evparts.com

(there are many more)

john is right go with about 2hp motor, a small golf cart controller maybe, 5k throttle

there is some how to manuals around by ben bidwell i think, great starter manual.
maybe someone has a link to that.

jdh2550_1
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Re: building an electric pit bike, where to start...... I have t

Sorry wrong URL - no "s" - it's http://www.electricmotorsport.com/PARTS/parts.htm - they list the EVT hub motor.

BTW, I'm not sure I'd build a bike with this hub motor. Also, rereading the original post in a little more detail it seems that he's converting an existing dirt bike - so the hub motor is probably a non-starter. Instead look at the good 'ol ETek and Alltrax combination.

If you want to do it for less money then start looking for low cost brushed DC motors in surplus supply stores. Something with 1HP continuous or more and with enough RPMs/Torque.

Search down a copy of John Bidwell's "Secrets of El Ninja" for a great book on the subject.

John H.
Blue XM-2000
Ann Arbor, MI
http://www.revevllc.com

John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas.

andrew
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Joined: Tuesday, November 28, 2006 - 17:21
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Re: building an electric pit bike, where to start...... I have t

The etek is a bit overkill for the speed you need. That's no reason it wouldn't work though. There are some more permanent magnet motors here:

http://www.robotmarketplace.com/marketplace_motors.html Check under the "NPC" and "Magmotors".

The motors at http://electricscooterparts.com are probably too weak, but might work if you lowered your target speed to 15-20, and maybe 25 but that would be a stretch even for the listed "1000" watt motors. There is a lot more to how a motor will perform than just its rating. TNC Scooters also carries these chinese pm motors for a bit less. The 1200 watt model might get you 25 mph.

http://www.thesuperkids.com/ carries some small permanent magnet motors for ebikes and scooters. Some of them include controllers like this one.

Search ebay for "permanent magnet motor".

I you rode a bit slower most of the time like 25 mph I'd bet 20 miles off road wouldn't be a problem with lead-acid batteries. The kind to get are AGM (absorbed glass mat). I'd recommend using B&B brand and the EVP series (these are their batteries with EVP in the model number) which which can be found at the following places:
http://www.electricrider.com
http://www.digikey.com
http://www.powerstream.com

For charging the batteries I recommend buying individual 12v chargers, one for each battery. This will keep the batteries balanced well.

I think most of the component selection depends on exactly what you want and why. What will you use your bike for? Could less range work? Could it work ok if it went slower? Is this just a fun project you want to do to get into the world of EVs before you build something better? Do you just want something that is electric and works?

If you answered yes to the last question you could put something like this motor in which has the controller integrated. Might only get your bike to 15 mph optimistically but I remember this motor on my ebike had amazing starting torque. All you'd need to do is mount a couple of batteries and a throttle and viola!

[url=/forum-topic/motorcycles-and-large-scooters/587-my-kz750-electric-motorcycle-project]KZ750 Motorcycle Conversion[/url]
[url=/forum-topic/motorcycles-and-large-scooters/588-fixing-my-chinese-scooter]900 watt scooter[/url]
Pic from http://www.electri

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