Motocross Style Electric Moped Project

[EVTodd]

I posted info about this in the picture section. I thought I would start a thread here for the official project.

Here is a picture of my semi-completed Garelli:

The thing is a blast with the Polini motor but I'm already tired of messing around with jets and oil/gas mixing, etc... I've kinda lost interest in the gas stuff which is why it's not 100% complete yet.

I think this is going to be my next electric project.

I have another Garelli frame that has rear suspension. I'm thinking about making something similar to a Motoped or a mini-Zero, lol. A lot of people convert mopeds to motocross style bikes with a motocross front fork, swing arm, etc. If you look for mob cross you'll see a lot of mopeds converted to something like this:

That one uses as Motobecane frame but you get the idea.

I need to get suggestions on motor/controller choices. I want to make this my daily work vehicle during the summer. I have a 5 mile ride (one way) and can charge at work so I don't need a lot of battery. Top speed only needs to be around 35 mph but I need it to be able to climb hills very well at around that speed.

 

[Dauntless]

That does look kewl. That crossbar across the top is a great idea if you do mean to do any dirtbiking with that. I remember us poor kids using the mopeds in college, mine wound up with a few welds it probably wouldn't have needed if I had that bar.

So you're looking for a nice peaceful NONDEATHBIKE, I take it. A moped can go 35mph with under 3hp, so you can with under 2,250 watts. But if you want to climb hills well 3hp comes up a little short on any moped I've rode.

I think of your wheels as turning 1,008 times in one mile. 35mph would mean 35,280 times in an hour. If your motor would cruise at 6,000rpm and you had a 72 tooth sprocket in back you'd need a 12 tooth pinion on the motor. A 3,000rpm motor would need a 6 tooth pinion just like on a pocketbike.

Now the great question that I get the idea no one can answer for sure: What is the REAL rpm of the motor under a load? I've seen a good number of questioners just wanting to be sure, but no real answer. I assume it can vary according to the motor itself and what the load really is too much for there to be a 'Formula' for someone to give out. My solution appeals to my more R&D type thinking: If you have the 3,000rpm motor, get a bigger pinion than 6 tooth, somewhere in the 7-9 range. Maybe if you pick a motor and controller people here are familiar with they can give you a more specific approach.

Right here they'll start you out around $1,000 with shipping at 12h for most of what you'll need.

http://www.electricmotorsport.com/store/ems_ev_parts_kits.php

If you want to experiment the RC motors are in, but you'll piece that together yourself. Alien has been known to answer questions right here on the board.

http://alienpowersystem.com/shop/80mm/c80100-outrunner-brushless-motor-130kv-7000w/

I've been raising my older brothers and sisters kids since I was in gradeschool. (Literally) It's always been a matter of ". . . .If that don't work I'll try something else." Works every time. (Eventually.)

 

[EVTodd]

The frame bars help a lot on a moped. The one on my Garelli is just a bolt on bar but if I go ahead with this project the frame I use will have one welded on.

I really don't plan on using it off road. I just like the look of motocross bikes. I really like the electric version of the Motoped and that's kind of what I'm going for here but with a titled bike that can legally be used on the road. I plan on keeping it within the moped laws (well, close anyway ) which is why I don't need a very high top speed. I would like it to be quick getting to those speeds though. I have a steep hill on the way home too so I need to keep that in mind.

As I mentioned, it's primary use will be riding it to work which is only 5 miles from my house. All of the back streets I can use getting there have a 25 or 30 mph speed limit so something like this might be perfect for me.

I think downhill bike parts on it would be cool (again, like the Motoped), especially the forks but since mopeds use 1" forks I'll probably have to find a dirtbike version instead. They are a LOT cheaper anyway. I am toying with the idea of a downhill bike swingarm on the back but I'm not sure how that would limit my wheel/tire choices. I'm thinking about sticking with moped wheels since you can get dot approved tires easily.

As usual I'm trying to figure out the least expensive way of doing this. I don't know if I want to spend over $1000 on a motor/controller kit. Maybe I'm crazy thinking I can do it for less money. If that ends up being the case I'll consider just getting a Zero or a Brammo Enertia for next riding season but building it is half the fun.

A monster outrunner would be cool but controllers are the big sticking point with them. Didn't someone mention that Alien isn't shipping to the USA now?

 

[Dauntless]

I feel certain that not shipping to the U.S. will be a misunderstanding. They have product on eBay and there's a U.S. price. I asked in a thread the guy is active in.

http://www.ebay.com/itm/Alien-150A-2-12S-Boat-Twin-ESC-HV-brushless-speed-controller-new-twin-model-/271143725462?pt=UK_ToysGames_RadioControlled_JN&hash=item3f216ce996

Now that is the one that people are hoping will be the lightweight programmable RC controller of their dreams, since the Castle almost works but doesn't quite survive all the time.

Meanwhile, here is the controller that many in the RC motor crowd recommends. They claim no troubles with the 80100 and 8085 motors for years on end. It works with a plain old throttle grip. . .

http://kellycontroller.com/ksl4820024v-48v200asensorless-bldc-controller-p-662.html

. . . .while the RC controllers require a BEC, a servo tester, etc., or some other variation. Great thread on how all that is done:

http://endless-sphere.com/forums/viewtopic.php?f=28&t=12196

Either Skyhobby is gone or they don't carry the 80100 anymore. There's a link here to get a 'Colossus,' similar at least.

http://endless-sphere.com/forums/viewtopic.php?f=31&t=52083

Meanwhile, how does $200 or less with shipping sound? You overclock this thing at 48v it'll be 1,300 watts, gear it for 35mph and you'll get up there sooner or later, (Coff coff) but you'll be slowing a bit uphill, I guess doing some pedaling if it's geared so you can pedal at 35mph.

http://www.monsterscooterparts.com/36-volt-1000-watt-motor-controller-throttle-kit-standard.html

I first got my idea for that sort of build from the idea of scrapping a broken Currie. All parts onhand. There's 750w, 900w and 1000w. I never seem to be able to lay my hands on one when they pop up on Craigslist at $75-125. The batteries would probably be shot but you'd get a charger. Just another avenue.

Either Skyhobby is gone or they don't carry the 80100 anymore. Somewhere there's a link here to get a 'Colossus,' similar at least.

 

[EVTodd]

I feel certain that not shipping to the U.S. will be a misunderstanding. They have product on eBay and there's a U.S. price. I asked in a thread the guy is active in.

http://www.ebay.com/itm/Alien-150A-2-12S-Boat-Twin-ESC-HV-brushless-speed-controller-new-twin-model-/271143725462?pt=UK_ToysGames_RadioControlled_JN&hash=item3f216ce996

Now that is the one that people are hoping will be the lightweight programmable RC controller of their dreams, since the Castle almost works but doesn't quite survive all the time.

Meanwhile, here is the controller that many in the RC motor crowd recommends. They claim no troubles with the 80100 and 8085 motors for years on end. It works with a plain old throttle grip. . .

http://kellycontroller.com/ksl4820024v-48v200asensorless-bldc-controller-p-662.html

. . . .while the RC controllers require a BEC, a servo tester, etc., or some other variation. Great thread on how all that is done:

http://endless-sphere.com/forums/viewtopic.php?f=28&t=12196

Either Skyhobby is gone or they don't carry the 80100 anymore. There's a link here to get a 'Colossus,' similar at least.

http://endless-sphere.com/forums/viewtopic.php?f=31&t=52083

Meanwhile, how does $200 or less with shipping sound? You overclock this thing at 48v it'll be 1,300 watts, gear it for 35mph and you'll get up there sooner or later, (Coff coff) but you'll be slowing a bit uphill, I guess doing some pedaling if it's geared so you can pedal at 35mph.

http://www.monsterscooterparts.com/36-volt-1000-watt-motor-controller-throttle-kit-standard.html

I first got my idea for that sort of build from the idea of scrapping a broken Currie. All parts onhand. There's 750w, 900w and 1000w. I never seem to be able to lay my hands on one when they pop up on Craigslist at $75-125. The batteries would probably be shot but you'd get a charger. Just another avenue.

Either Skyhobby is gone or they don't carry the 80100 anymore. Somewhere there's a link here to get a 'Colossus,' similar at least.

Thanks for all the suggestions. I really need to sit down and research what's out there. I'm used to smaller bike size motors so all of this is a bit new to me.

As much as I want to be cheap it's really more important to have plenty of power. If I can't figure out a way to have excellent hill climbing ability at around that speed it won't be worth messing with.

The pedals are probably going out the window too. You don't need them where I live to still be considered a moped. I have no desire to pedal a heavy moped up a hill .

 

[EVTodd]

Just found this photo of an electric moped. What motor is that?

 

[Dauntless]

If this is A TRIVIA GAME< I'm on the board first.

Briggs & Stratton ETEK. No longer on the market, though Mars will have equivalency. The original Etek was like 10kw continuous and 20kw peak. Or maybe there was more than one.

You've come to the right place, there'll be people to help you out on this one here.

 

[EVTodd]

Briggs & Stratton ETEK

Thanks for the info! I've seen them before on the forum but like I said, this is my first real look into the world of electric motorcycle size motors.

My big concern with something like that is the weight. That has to weigh more than the original motor. Then with the batteries... If I end up doing this I will have to strengthen the frame for sure.

 

[gogo]

My big concern with something like that is the weight. That has to weigh more than the original motor. Then with the batteries... If I end up doing this I will have to strengthen the frame for sure.

Moped engine/trans weigh 20-30 lbs. depending on the transmission. The engines that use a belt and pulley for reduction are lighter than those with enclosed gear cases. The 'single beam' frame is fairly strong by itself. When you make it into a (semi) triangulated frame by adding a battery box as an upper element, it should be plenty strong.

An advantage of the pulley-reduction format is the possibility of using a cheap larger diameter hub motor at a faster than in-wheel speed. If you need more power for your hills you can easily change the voltage and gearing. Cheap commodity ebike parts FTW!

 

[EVTodd]

Moped engine/trans weigh 20-30 lbs. depending on the transmission. The engines that use a belt and pulley for reduction are lighter than those with enclosed gear cases. The 'single beam' frame is fairly strong by itself. When you make it into a (semi) triangulated frame by adding a battery box as an upper element, it should be plenty strong.

An advantage of the pulley-reduction format is the possibility of using a cheap larger diameter hub motor at a faster than in-wheel speed. If you need more power for your hills you can easily change the voltage and gearing. Cheap commodity ebike parts FTW!

The Garelli unfortunately doesn't use a variated system with a belt drive. I rebuilt the ice motor on this bike. I don't recall it being quite that heavy but I could be wrong. I'll have to pull it off and weigh it. I'm curious on how it compares to some of the bigger electric motors.

I will say the frame is built like a tank. I suppose with a stress bar welded on it will be fairly sturdy.

The hub motor idea is interesting but I'm not sure how it would be mounted on a frame like this. The one in the picture above would be fairly easy to mount on my bike since I have mounts for a motor front and back. I could cnc up a couple of beefy mounts to match them up.

Time to start looking at motors. What is the smallest motorcycle style motor like this on the market right now?

 

[gogo]

Your Garelli is listed as 18 lbs. dry. You may want to figure out how large a rear sprocket you can fit without interference from the swingarm. It may be possible to substitute a swingarm from a moped that uses larger sprockets, if needed.

 

[EVTodd]

Your Garelli is listed as 18 lbs. dry. You may want to figure out how large a rear sprocket you can fit without interference from the swingarm. It may be possible to substitute a swingarm from a moped that uses larger sprockets, if needed.

I actually have another Garelli frame I'll be using. The one in the picture is a hardtail and would be very limited on gearing. The plan is to use a motocross style swing arm on it so sprocket size shouldn't be a big issue.

 

[1KW]

im trying to build the same thing...what about a turnigy 80100? with halls? Or a 20" hubby in rear?

 

[EVTodd]

im trying to build the same thing...what about a turnigy 80100? with halls? Or a 20" hubby in rear?

Very cool. What bike are you using for a starting point?

I thought about a Turnigy 80-100 with added halls but isn't that motor almost impossible to find now? What would be a good esc to use in this application with that motor?

 

[1KW]

Its on electricbike.com store I believe.

I am using a tube frame from ebay(25 bucks!) Its a toptank model so I can mod a large gas tank as a battery pack holder..

Example..

Sort of a homemade ped like this...except pull the ICE engine, throw a HS cryst with 100v of battery under the gas tank, and the rest of battery in a box where the original ICE engine used to be.

 

[EVTodd]

Its on electricbike.com store I believe.

I am using a tube frame from ebay(25 bucks!) Its a toptank model so I can mod a large gas tank as a battery pack holder..

Example..

Sort of a homemade ped like this...except pull the ICE engine, throw a HS cryst with 100v of battery under the gas tank, and the rest of battery in a box where the original ICE engine used to be.

I'm not sure a hub motor would be the best choice since I really want hill climbing ability more than anything. I'm really hoping not to have anywhere near that kind of voltage either.

I'm really starting to think about going the outrunner route if I can find a suitable motor... Or two ... It would make mounting so much easier and the weight savings would be huge. Making it reliable is my concern. I suppose I need to read up on how to rewind an outrunner.

These moped frames are heavy but without the original motor there's not THAT much mass to move. I figure if I can go 30 mph with 36 volts on my friction drive outrunner setup (normal bike) then it wouldn't take much more for a moped to go 35 mph.

 

[Dauntless]

http://endless-sphere.com/forums/viewtopic.php?f=28&t=52951

 

[EVTodd]

http://endless-sphere.com/forums/viewtopic.php?f=28&t=52951

???????

 

[1KW]

http://endless-sphere.com/forums/viewtopic.php?f=28&t=52951

???????

lmao..

I would love to do a 80100 also, how hard to add halls to one? Is 35mph feasible top speed with good torque out of a 80100?

 

[EVTodd]

http://endless-sphere.com/forums/viewtopic.php?f=28&t=52951

???????

lmao..

I would love to do a 80100 also, how hard to add halls to one? Is 35mph feasible top speed with good torque out of a 80100?

It doesn't look like adding halls would be hard at all. Biggest problem is getting your hands on the motor. Electricbike.com is out of stock and from what I've read on other threads there doesn't seem to be any to be had anywhere.

Oh well, I'm going to start working on the frame and suspension first. I think I'm going with a kx80 fork. No idea about the swing arm yet. I'll post up some photos soon to see of any of the engineer types here have any suggestions.

 

[1KW]

Yep, kx80 forks are super beefy and like 50 bucks.. why are we not putting these on high powered ebikes instead of 700 dollar bombers...

 

[EVTodd]

Yep, kx80 forks are super beefy and like 50 bucks.. why are we not putting these on high powered ebikes instead of 700 dollar bombers...

I thought that myself. Probably because they fit a 1" head tube. I actually wanted to put downhill forks on it but that's too rich for my blood and I don't think it's possible anyway.

I keep eyeing the kx80 swing arms too but I have no idea if I can make it work on my frame.

 

[EVTodd]

Ok, I change my mind every other day but I think I'm going to keep the basic look of this moped the same as original instead of going with a motocross look. I have some changes in mind but I've already spent the money on new forks and some other mods. May as well use what I have.

I'm also thinking about building a hybrid type system so I can use the original motor or electric.

Anyone wanna guess how I'm planning on doing it? Here's a hint... Everyone will say it won't work. lol

 

[Dauntless]

Anyone wanna guess how I'm planning on doing it? Here's a hint... Everyone will say it won't work. lol

OH OH OH! I KNOW I KNOW!

Everyone says it won't work, so that means that you're going to do it---

WRONG!

 

[EVTodd]

Anyone wanna guess how I'm planning on doing it? Here's a hint... Everyone will say it won't work. lol

OH OH OH! I KNOW I KNOW!

Everyone says it won't work, so that means that you're going to do it---

WRONG!

Lol. If I'm wrong I don't want to be right!

We'll see. It wouldn't be the first time I was told my ideas were wrong on this forum. Funny thing is my last "wrong" idea is pretty much my daily ride to work and has been for the last 4 years.

Let the madness begin!!! BAHAHAHAHAHAHAHAHAHAHA!

Ok, so it's not THAT exciting. lol