# Electric Moped Conversion



## papaslides (May 18, 2008)

Hello all, I am new here so I'm interested to hear from this community.

I am looking for help in designing an electric moped. Here is my thought, I need a commuter vehicle that can get me to and from work (about 7 miles), can make it up somewhat steep hills. And here's the real clincher, my budget is about 400-600$, with this in mind I'm thinking a DIY project. I was inspired by Ben Nelson's DIY electric motorcycle but the 2000$ price tag it was a bit beyond my needs, besides I've never been to sure about motorcycles but I feel safe in my ability to use a moped.

I am thinking buy an old moped with a dead or dying motor for cheap (around or under 100$) and put in the electronic components... possibly with (or with the ability to later upgrade) pedals for greater range/exercise, and of course the ability to move if the batteries die. Because of how many hills there are in Ann Arbor (where I live) I think designing it to use regenerative breaking would be advantageous (I'd say 40% of my commute is uphill, 40% downhill, and 20% more or less level). The 500$ or so price tag I'm aiming for is startup cost to get this thing on the road and usable, I realize some features may have to wait until later, but that 500$ needs to get me to and from work reliably and on a daily basis.

So what I'm looking for is any thoughts or ideas on how to make this possible.

Thank you

Sean


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## JohninCR (May 6, 2008)

With some good scrounging you can very likely come in under budget. I've recently gotten an electric bicycle going, and I have plans for a powerful moped from scratch. It will be more like a motorcycle with pedals to fall outside the law here in Costa Rica.

Since you mention exercise, you may want to consider converting a bike instead. With hills you'll need a powerful motor, gearing, and or significant pedal assist, and I think you have a greater chance of disappointment in performance with a moped. On the other hand, better brakes, signal lights, and more comfortable seat and ride definitely favor the moped route, but you should raise the bar cost-wise by $200-300. It's the hills that are the kicker.

I have hills to contend with too, and here's the major cost breakdown for my moped project:

Controller $150
Motor $250
Comet torque converter (continuously variable transmission) $200

This isn't including batteries, charger, cables, sprockets, chain, etc. Plus I feel that I did well on the motor and controller through Ebay. That's not to say you can't reduce costs significantly with good scrounging, but the flip side is that easy to install complete kits for a bicycle can be had for less and you help pedal up the hills.

John


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## swampjeep (May 16, 2008)

I've been researching the electric bike way too, does anyone have knowledge about these kits http://cgi.ebay.com/Electric-Bicycl...oryZ7295QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

it looks cheaper and much easier to go with something like this then to do it all from scratch, even though I woulf very much like the knowledge I would gain from piecing it all together. I just can't seem to find anythign that compares, and I can't find hub motors for close to the price of this complete kit.

EDIT: I think I like these better http://www.electricrider.com/crystalyte/index.htm


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## electro37 (May 18, 2008)

please contact me @ [email protected] aboiut the torque converter you mentioned in the blog. I too want to build a moped for work and I have no financial "restrictions". I have never hear of torqu converters except in big old US cars!!
Thanx, electro37(Ron)


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## electro37 (May 18, 2008)

thanks a million John, I'll be interested to see how you manage with the moped... our law got changed here;(after many months of petitioning and haggling with the Motor Vehiclr Branch) so that any bike with electric assist does not need a licence, Insurance, anything except a rider as long as the assisting motor does not exceed 500Watts, the bike has 14" or over diameter wheels, and cannot travel under power alone at more than 30kms/hour, so with a bit of pedalling you can go 40kms/hr. if you can pedal hard enough!!!!!


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## MitchJi (Dec 14, 2007)

JohninCR said:


> \
> 
> I have hills to contend with too, and here's the major cost breakdown for my moped project:
> 
> ...


Hi John,

Would you mind posting a link for the Controller, Motor and especially the torque convertor?

Thanks!

Mitch


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## JohninCR (May 6, 2008)

Here's a link to the Comet Torq-A-Verter and the best price I could find. I've seen a dual Etek motor cycle that used this or a similar unit, but note that the stock design is for a gas motor, so it doesn't engage until 2200rpms. I plan to modify it to lower the engagement rpms for my electric motor. The planned result is an efficient and cheap CVT (Continuously Variable Transmission) with a 2.7:1 to .9:1 gearing range, which I believe is necessary for me due the hills here. http://www.mfgsupply.com/GoMiniClutchTorqTAV30Kits.html/mv_session_id=YxLEAPcH

I bought the motor on Ebay, which was supposedly designed for a scooter that never materialized that would carry 2 people to 50mph.

My controller is a Curtis 1205-205 good for 36-48V and 350A peak, that I also picked up new on Ebay for a song. I have another slightly lower power programmable Kelly controller that I lucked out and picked up for $99 before prices went up that I could also use.

John


Ron,
You are very welcome. I'm lucky the laws here apply only to fuel powered vehicles >49cc, so as long as I have pedals there are no limits. Plus I don't have to do the annual lines or incur the costs of annual registration and inspection. Top it off with traffic laws being guidelines to establish accident fault instead of enforced rules, and efficiency in traffic becomes drastically higher with 2 wheels vs a car. ie weaving through stopped cars, sidewalks...whatever, are all fine.


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## MitchJi (Dec 14, 2007)

Hi,

Anyone familiar with the Nu Vinci which looks like an excellent CVT:
http://www.fallbrooktech.com/NuVinci.asp


> The patented _NuVinci _technology developed by Fallbrook Technologies Inc. (Fallbrook) is the most practical, economical and universally adaptable continuously variable planetary (CVP) transmission for human-powered and motor-powered vehicles and machines. The _NuVinci_ CVP is ideally suited for applications in many major industries including bicycles, light electric vehicles, tractors, automobiles, trucks, and utility class wind turbines among others.


http://www.fallbrooktech.com/06_FAQ.asp


> NuVinci bicycle aftermarket kits are available to bicycle retailers from the following distributors:
> 
> Seattle Bike Supply www.seattlebikesupply.com
> Quality Bike Products www.qbp.com
> ...


Available here for $380:
http://www.bikemannetwork.com/biking/p/COMPHUINT/SBS-138311


> NuVinci CVP Rear Hub, 36H Black
> Code: SBS-138311
> Price: $377.95
> 
> NuVinci CVP Rear Hub: 36h, Black. CVP (Continuously Variable Planetary) drivetrain technology with infinite number of ratios. Simple twist controller enables easy, continuous ratio adjustments while pedaling, coasting or at a stop. No missed gears, hesitation or noise. Includes CruiseController shifter and 17t freewheel. Includes Brake Kit to accommodate disc brakes, roller brakes and rim brakes.


Thanks!

Mitch


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## JohninCR (May 6, 2008)

Update on the Comet Torq-A-Verter designed for gokarts. Comet responded to my info request that they have springs that will reduce the engagement to 1400rpm, OR "you can remove the springs all together and have instant engagement". I'm going to try the no springs route and report back.

Note: This Comet unit weighs too much and is too bulky for a bicycle solution, but it seems to make sense for an E-moped or E-motorcycle.


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## COMP (Jun 4, 2008)

anything new ??


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## MikeN (Jun 8, 2008)

No updates on this? I'd like to know more about the modified CVT to work with the lower RPM electric motors.


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## JohninCR (May 6, 2008)

MikeN said:


> No updates on this? I'd like to know more about the modified CVT to work with the lower RPM electric motors.


I hope to get a frame cobbled together this week, in order to give this thing a go. I'll report back with results both with and without the engagement springs as soon as I have something to report. I understand that some of the more expensive units are far more adjustable, making the engagement rpm less of an issue.

John


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## JohninCR (May 6, 2008)

Update on the Comet Torq-A-Verter: Frame mods took longer than I thought once I realized I had to lengthen the wheelbase to allow sufficient travel with the motor mounted on the swing arms, so sorry for the delay...too many EV projects at once.

Not on the street yet, but the CVT works like a charm in spin tests. Definitely have to remove or change the springs, since 2200rpms is too high for engagement. I took the springs off and at very low speed there is some noise with the weights not held in place by the springs. I'm going to try some much lighter weight springs, though the 1400rpm springs from Comet may be ok. No springs is ok too, unless a little low rpm rattle bothers you. It only exceeds chain noise at very very low rpm.

Wiring switch and throttle, plus a seat is all that prevent a road test, so hopefully I get some testing in before heading to the beach for some R&R later this week. Getting my ebike running, not emoto, takes priority this week, but I do want to get some test rides on the emoto this week.

Basically, I know the concept works and the question to be answered is belt life, but that will hopefully take a long time to report on, so no news is good news on that part of the equation.

John


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## JohninCR (May 6, 2008)

Took it out for a spin today, and everything works fine though the 100/200A Kelly controller fell woefully short. That is unless I didn't save the controller setting changes I did the other night. Also, I'm not getting the rpms I'd hoped for, so time to throw some more voltage at the motor too.

I'll get back with more complete details later.

John


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## solarcruz (Jul 15, 2008)

since i am neither mechanically nor electronically inclined, only intellectually and environmentally motivated, i have opted to purchase an electric moped from thegostore.com and can't wait to try it out. i'll let you know how it goes. i have a few hills to contend with as well and that was one of my big concerns.


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## electro37 (May 18, 2008)

*Re: Electric Moped Conversion(hills)*

I can understand your "trepidation" about the hills, but; if you are able to use the pedals anything from 250 Watts upwards would be OK but if you'd find the bike hard to pedal; then you will need at least 500 Watts to navigate (climb) even mediocre hills or slopes. Pedalling; even lightly seems to give the bike approx. 1/3rd more torque. Try to remember that an electric motor runs most efficiently at full load; with the load it was designed for. At certain amounts of load and certain speeds; these losses are very noticeable as "motor slip".
For accessories on the moped 12 volts is quite sufficient and a small 12 volt battery would be good; using a 12 volt Zener diode circuit to keep the little battery "topped-up", from the main traction batteries. Keep me informed of what happens with your new aquisition!!!!!


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## solarcruz (Jul 15, 2008)

thanks so much for your input. in fact, it is 600 watts. so from what you're saying i should be ok. glad to know i can get 1/3 more power with pedaling. there is one somewhat daunting hill that i will need to take a couple of times a week and when i rode in a miles ev, i think it was a 72v, it really slowed by the time we reached the top of the hill and we had picked up speed coming down the hill before we started up, which isn't always possible because of 2 traffic lites at the bottom.
i'll definitely keep you posted. it will be about 8 days before it arrives via truck across country.
thanks again.


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## luke1470 (Feb 26, 2014)

isn't a CVT not needed with an electric motor, and because of that wouldn't it waste a lot of energy through it since it doesn't need that like a gas engine would?


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## Stampede (Jun 15, 2014)

I was wondering that same thing, but I think it maybe a case of the electric motor needing to use it's torque more effectively. Instead of just throwing it all in from go.


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## johnnywheels (Nov 19, 2015)

solarcruz said:


> since i am neither mechanically nor electronically inclined, only intellectually and environmentally motivated, i have opted to purchase an Airwheel Q6 from thegostore.com and can't wait to try it out. i'll let you know how it goes. i have a few hills to contend with as well and that was one of my big concerns.


I am certainly on the same page as you; motivated but not necessarily inclined. I recently purchased an Airwheels electric scooter and am excited to give it a shot around town! Not a moped but still just as fun to ride around in! Happy travels!


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