Electrified Downhill bike - Page 3 - RC-Monster Forums

01.02.2010, 12:23 PM

nah,forget electric,you need THESE--http://www.jetcatusa.com/p200.html

52lbs of thrust at 112,000 RPM and only 5lbs a piece for the low low price of 5,595.00$ ! LOL

cool build,wish i had the know how to do as much with electric as you guys do.--josh

johnrobholmes · 01.02.2010, 01:11 PM

ES is back up fellas. Server issues.

The bike should wheelie under power just fine. The wheelbase is short enough and I will have about 5 horse on tap. Probably won't see me popping wheelies though, I need back brakes first.

The stealth bike is pretty cool, but they are very pricey. You need an 18 fet Infineon controller and a Xlyte 5305 on 72v to have a setup similar, about $800 before batteries. Divorced drivelines like mine are MUCH lighter for the power (25lb vs 8lb), about the same price and power, and are much easier to service.

rootar · 01.02.2010, 11:48 PM

how much are we talking for batteries? 24s 5p life or 20s 20,000 lipo? and where can i find the said motor and controller?

what would you recommend with a divorced setup electronics wise?

and how pricey are the stealth bikes? i cant find a price on them anywhere?

johnrobholmes · 01.02.2010, 11:58 PM

I think the stealth bikes are 5 to 6 grand, but it depends on the currency rates.

For the rest I suggest you go to endless-sphere.com/forums and check it all out. There are hub motors that can work too, and developments in all areas at the moment.

The biggest thing is to pick out what type of riding you are going to do. Street riding, just cruising, off road, etc.

Metallover · 01.03.2010, 12:09 AM

For just the avarage electric bike I would expect to pay as little as $400-$500 plus a battery, but it can go up fast with better/faster electronics. A 44.4v 10ah 12s2p turnigy lipo pack would be an example and a 20c 6s 5000mah turnigy is just over $50..

http://www.ebikes.ca/store/store_nc.php

http://ampedbikes.com/kits.html

zeropointbug · 04.27.2010, 02:58 PM

I have been checking out electric bike conversions for a few weeks now and I think I would like to convert a downhill/freeride bike to electric power.

I don't know what you are using in your bike Metallover, but do you know if anyone has had good success with the MARS 12hp BL ETEK motor? I know it's not very efficient at low power as it has high idle current. With this motor you could easily hit 100+kph without the motor breaking a sweat. But, also because it's not very efficient on the low end, you have to keep your speed up there to return decent efficiency, otherwise it's quite bad, below 70%, even 250watts @48volts, you are only getting 50% efficiency. So you know what I mean. This route would be FUN for sure, but maybe not so simple, or as efficient, and even durable in a bike.

The other option is a Crystalite X-5 series wheel hub motor, capable of 2000watts at 72volts. This would be a more efficient and probably safer/smarter, cheaper, simpler way to go obviously. However I would like to have up around 3000watts or more, like what the "Stealth Bomber" bike has. I have looked and looked, but I can't find a wheel motor with more than 2000watts, or at least a controller that will drive it more than that.

I know a downhill/freeride bikes are very stable at very high speeds, so I would like to be able to have a top speed of upwards of 100km/h or 60 mph... some of you might think that is way too fast, but i have held onto a car going 80km/h and it was absolutely fine, so I say 100k is doable.

The Stealth Bomber bike is exactly what I would like to do, as far as setup and looks. Would I be able to get a hold of the 3000watt wheel motor that they use? Do you think it is custom made motor? Or just over volted to obtain that power output?

-Batteries are most likely going to be A123 cells, either M1's or the new "Industrial cell" that Enerland/A123 has under 'coming soon' .... if not, then Headway cells are an option as well.
-Range I would like at 60km/h is around 40 miles

At this moment I don't know what route to do as I haven't seen anyone use the MARS BL ETEK motor in a bike except for this guy, but he is using a poor setup and appears to be using some weak lead acid batteries with it, which doesn't make too much sense. lol

Would like to hear some input from anyone who has built an Ebike.

zeropointbug · 06:58 PM

Here is a pic of the frame I would like to use, if my oldest brother will let it go... although not the actual bike, that is the Ellsworth Joker frame. Can't remember the brand of forks, but everything on the bike is top of the line parts. Looks to be plenty of room under the frame for batts and electrics.

Also a pic of the MARS Brushless ETEK.

Metallover · 04.27.2010, 05:14 PM

Here's a pic of my bike as it stands now (click for a direct link to the pic w/o photobucket crap)

I am running
9c (9x7) 26" rear hub motor
66.6v 10ah turnigy lipos
Ecrazyman 72v 45a controller
Hobbyking voltage/temperature monitor
Hyperion eos0610i charger

And on my list (recommended items)
Maxxis hookworm tires
More powerful power supply (8 hour charges suck

)
Cycle Analyst
Controller usb hookup (mainly to change the amp limit)
-Also am considering making the motor delta/wye switchable

The Hobbyking VT monitor is great. It provides readings and an alarm for low voltage and high temperature, in this case my motor. I wrote a review (at a great ebike forum) - http://endless-sphere.com/forums/vie...17958&p=262221

I got my controller from this guy on ebay. His name is Keywin and he is very helpful/knowledgeable and is a pleasure to deal with. His prices are great too. You can send him a message and tell him what you need. Tell him your motor and your voltage for an ebike and he should be able to pick you out a great controller. Let him know what you want for a lvc; I excluded the lvc. I have the 72v/1500w controller. 12fet iirc. He has larger and smaller controllers.

You can email him at ecrazyman@gmail.com

Keep in mind there are many other places that sell controllers/kits.

minimum you will need motor, controller, throttle, and torque arm(s). About everyone would recommend running 2, especially if you're running 750+w.

PBO · 04.27.2010, 06:20 PM

Quote:

Originally Posted by rootar

THIS is what i want!
http://www.stealthelectricbikes.com....th_bomber.html

only 125 pounds, it could replace my pitbike, can anyone find out how much they cost or give me a breakdown on what it would run me to put one together on the same level of power and range? Ive watched vid of a bunch of bikes but those stealth bikes REALLY changed my mind on these Ebikes.

I've sent an email asking the obvious questions, including price. I'll post the response when it arrives

PBO · 04.27.2010, 10:17 PM

John at Stealth was very helpful & supplied the following information. Remember prices are is Australian dollars...AUD $1 = USD $0.91 (today)

Purchase price?

Standard Bomber - $6990 AUD
Standard Fighter - $5490 AUD
White Brothers fork upgrade - $1000 AUD
8 Pot brake upgrade - $400 AUD

Battery type, capacity etc?

Lithium (LiFePO4) 1.5kWh

Can I parallel in additional cells for longer rides?

In theory yes... in reality... you would have nowhere to put them... The
batteries consume the entire inside of the frame and weigh about 15kg.

Motor manufacturer?

It's based on a Crystalyte X5 but has a few of our own mods made.

Does the bike come with charger?

Yes

Servicing cycles/requirements?

Less than a normal mountain bike. Brake pads and chain are really the
only things that wear. I had a bike come in for a 6000km service a few
weeks ago and that was all it needed.

Lead time from order?

About 4 weeks

I'm seriously thinking about getting one of these now. What a machine!!

zeropointbug · 04.28.2010, 08:08 PM

okay, thanks for the info. I mentioned these electric kits to my young brother out of university and he would like to add a ~350 - 500watt wheel motor kit on his bike, along with an A123 pack, for about 15-20 mile range unassisted at maybe 40km/h?

It needs to be a rear hub motor, and have 8 speed cassette with disc brake mounting. I would like for it to be a 36V unit, as that would allow me to run a nice 12S A123 pack.

I have looked around for kits, some are what I'm looking for, but are front only hubs, then some are rear, but no disc brake....etc. Just trying to find the right one!

He will spend $400 for a kit NOT including batteries.

zeropointbug · 04.28.2010, 08:49 PM

I agree they are seriously beautiful bikes. Really, they would pay for themselves in a matter of a year you drive to work everyday.

I was suspecting they were using the Crystalyte motor, I wonder what they did to it without changing in any significant way. Even the best hub motors are not built anywhere near the quality/performance that we R/Cers enjoy.

Metallover, I have looked at many kits, I keep going back to the Ampedbikes kit for $350, gives you 23mph, maybe 25 with a little extra influence (voltage

), but the one thing I am wondering is if they can take a 8 speed freewheel?

I am also eyeing up the Nine Continent kits, as I can buy these within Canada.

Also, if anyone has any experience with the A123 cells from the Chinese suppliers, let me know how they are, performance, used?, capacity, number of dead cells when purchased, etc.

http://cgi.ebay.ca/20x-A123-3-3V-230...item19bbd8d6c6

zeropointbug · 02:15 AM

Found an article on A123's next gen cell, a 20Ah prismatic. They also said some 4, 6, and 8Ah cells are due to be produced as well? That would be nice for us RCers. It says cost will be drasticall reduced, power density has doubled

and energy density has gone up as well, 50%, on par or higher than LiPo apparently. The 26650 is 100Wh/kg, so 150Wh/kg vs. 140 Wh/kg for Lipo?

The prismatic cell features an increased energy density through new anode and cell designs. New materials provide increased cycle life and energy density. On the cathode side, A123Systems has scaled up its efforts to reduce costs through improved and more efficient processes, and continues to expand cathode development to improve both capacity and energy.

At the cell level, the energy density (Wh/kg) of the new 20Ah cell is 50% greater than that of the old 26650 cylindrical cell (from 2007), while the module level energy density increased by 30%.

Finnster · 04.29.2010, 03:24 PM

Quote:

Originally Posted by zeropointbug

Found an article on A123's next gen cell, a 20Ah prismatic. They also said some 4, 6, and 8Ah cells are due to be produced as well? That would be nice for us RCers. It says cost will be drasticall reduced, power density has doubled

and energy density has gone up as well, 50%, on par or higher than LiPo apparently. The 26650 is 100Wh/kg, so 150Wh/kg vs. 140 Wh/kg for Lipo?

The prismatic cell features an increased energy density through new anode and cell designs. New materials provide increased cycle life and energy density. On the cathode side, A123Systems has scaled up its efforts to reduce costs through improved and more efficient processes, and continues to expand cathode development to improve both capacity and energy.

At the cell level, the energy density (Wh/kg) of the new 20Ah cell is 50% greater than that of the old 26650 cylindrical cell (from 2007), while the module level energy density increased by 30%.

Looks cool, I'd really like to see some new A123s come out.

Nice ebikes guys. Question tho, is there any other ways other than the twist-grip unit to interface w/ a esc using PWM?

Basically I'm starting another project, but its going to be a ride-on power wheels for my son. They just use relays to control on/off power supply from the motor to cheap johnson electric motors. I can use a number of old brushed controllers just fine (even inexpensive BL controllers) but I'm trying to figure out a way to interface the foot pedal to the esc using PWM.

Metallover · 04.29.2010, 06:00 PM

Quote:

Originally Posted by zeropointbug

okay, thanks for the info. I mentioned these electric kits to my young brother out of university and he would like to add a ~350 - 500watt wheel motor kit on his bike, along with an A123 pack, for about 15-20 mile range unassisted at maybe 40km/h?

It needs to be a rear hub motor, and have 8 speed cassette with disc brake mounting. I would like for it to be a 36V unit, as that would allow me to run a nice 12S A123 pack.

I have looked around for kits, some are what I'm looking for, but are front only hubs, then some are rear, but no disc brake....etc. Just trying to find the right one!

He will spend $400 for a kit NOT including batteries.

http://ampedbikes.com/kits.html

Excellent deal. Great service. Highly recommended.

I'm (afaik) running the same motor and my controller is limited to 20a, altough I am running much more voltage.