Currie-EZip ebike Kit $289.88 - Amazon.com

[DrkAngel]

Have I got this right? Take 2.

Simplest - most basic, explanation of how a brushless motor works.
Power is regulated by modulating the amperage applied to the motor, by the controller.
(Typically, in a regulated, 3 phase arrangement. )
This is done via a series of full voltage pulses, the width, and quantity of which, determines the power input, (amps x battery voltage).
Additional amps supplied, increases motor "torque", but does not affect the "unloaded" ** top speed.
Amperage application is limited by controller capacity - or as a function of thermal decay.
(Electrical resistance of wire increases, as its temperature rises.
The application of more amps, shifts efficiency lower, as heat to torque ratio, increases.)
200% amp input might increase output to 150%. (Which Increases watt output, also.)

Additional, speed, as well as rated motor output - "watts", is obtained via the increase of supplied voltage.
Ex. Upgrading from 24v to 36v will enhance output, from 500w to 750w, which raises the torque curve, as well as increases the top "unloaded" ** speed by a full 50%.

Note: The "output" or "motor rated", "watts" is a fraction of the input "watts".
1000w input might produce a, usable, 750w output, = 3/4 = 75% efficiency rate.

** "Unloaded speed", is specified, to avoid, having to, explain-factor in, wind resistance, road load, component resistance etc., which are significant, measurable, factors during actual usage.

Please Note: I'm trying to keep this as simple-basic-understandable as possible!

[TylerDurden]

To keep it simple, don't use "amps" and "power" synonymously (that is misleading).

IIRC:

Controllers switch the power to the motor at a high rate and shift the percentage of on-time to off-time (PWM duty-cycle).
Whereas the motor windings act as an inductor, the average voltage in the motor is proportional to the duty-cycle; changing motor speed.
Whereas Power=Current*Voltage, lowering the average motor voltage via PWM results in a lower current drawn from the batteries (but higher current in the motor).

Brushless controllers also handle the commutation, sequentially sending PWMed power to each phase.

[torqueon]

I am trying to get my head wraped around this as well. I think what AW is descirbing kind of goes like this

Brushed motor PWM controll would look like this -----------

Brushless 3 phase PWM controll would look like this
Phase 1 --- --- --- ---
Phase 2 ...--- --- --- ---
Phase 3 ......--- --- --- ---

Setting aside controller and motor variables ( controller limts, motor load etc. ) Effective voltage is varied by the with of each pulse witch effect the amperage draw by the motor

Hope this make sense if I am wrong hear please Hollar

[TylerDurden]

http://adamone.rchomepage.com/guide5.htm

[torqueon]

Thanks Tyler

[gogo]

Effective voltage is varied by the with of each pulse

The width of the pulse alone (time) has to do with the frequency, voltage has to do with the ratio of on/off of the pulses.

Others have written about the effect of the frequency, IIRC it needs to be within a range, not too high or low.

[torqueon]

Understood! sorry for being vague

[DrkAngel]

Previously, it has been possible to buy the entire EZip bike for around $300, sadly, haven't seen anything near that, in almost 1/2 a year.
Present prices are in the $500 - $600 range.
Possibly some clearance items, come Fall, when sales slow down?

[gogo]

Previously, it has been possible to buy the entire EZip bike for around $300, sadly, haven't seen anything near that, in almost 1/2 a year.
Present prices are in the $500 - $600 range.
Possibly some clearance items, come Fall, when sales slow down?

Yes, I think winter is slow for ebike sales and they try to move the ones with lead-acid batteries. I've snagged an eZip for $225 on 12/12/08 and an EZgo for $275 on 12/24/09 from Amazon. I haven't seen an eZip for less than $300 since, though. I do a search for all Currie products whenever I'm on the Amazon site.

[DrkAngel]

Previously, it has been possible to buy the entire EZip bike for around $300, sadly, haven't seen anything near that, in almost 1/2 a year.
Present prices are in the $500 - $600 range.
Possibly some clearance items, come Fall, when sales slow down?

Yes, I think winter is slow for ebike sales and they try to move the ones with lead-acid batteries. I've snagged an eZip for $225 on 12/12/08 and an EZgo for $275 on 12/24/09 from Amazon. I haven't seen an eZip for less than $300 since, though. I do a search for all Currie products whenever I'm on the Amazon site.

I've, also, seen great deals at Walmart, Super Kids, Toys-R-Us.

[DrkAngel]

Of course, for the "innovator", the motor, alone is available!
450w 24v, gear reduction motor, standard 1/2" x 1/8" chain (MY1080Z) - $65 + shipping

MY1080z.gif (37.01 KiB) Viewed 618 times

Rated for 24v, but runs nicely from 12v - 36v.

Generic controllers available, $20 - $40 +-.

HAL throttles - $10 - $15

"Kit" for $!00? Then add battery.

[wineboyrider]

Of course, for the "innovator", the motor, alone is available!
450w 24v, gear reduction motor, standard 1/2" x 1/8" chain (MY1080Z) - $65 + shipping

MY1080z.gif

Rated for 24v, but runs nicely from 12v - 36v.

Generic controllers available, $20 - $40 +-.

HAL throttles - $10 - $15

"Kit" for $!00? Then add battery.

That's where I bought my ezip replacement motor that I fried with 36v lifepo4 and 2000 miles

[DrkAngel]

That's where I bought my ezip replacement motor that I fried with 36v lifepo4 and 2000 miles

Correct! Full throttle from dead stop, dogging it up hills etc. can cause overheat damage.
Solutions:
Add active cooling
or ...
36v, upgraded Ezip, guidelines:
1. Pedal assist "up to speed"
2. maintain 12mph or higher during full throttle
3. if you drop below 12mph on a hill - reduce throttle!

At 1 mph full throttle puts 5% energy onto the road - 95% damaging heat!
80% road energy - 20% heat, is reached at, from about 50%, to 95% of top speed. (top speed 24mph@36v)

This "Sweet Spot", of motor efficiency, varies with throttle position!
1/2 throttle drops this sweet spot toward 6 - 12mph

So ... pedal with enough assistance to maintain efficient speed - reduce % damaging heat ...
Or ... reduce throttle, to attain efficient energy usage ...
Or ... apply the optimal combination.

I've run 2 EZips @37v for 3500miles and 3000miles, no heat problems! (includes running 1 through 2 Winters, yeah, I know ... not liable to overheat during Winter.)

[wineboyrider]

It's hotter than hell here in NM in the summer. I used for short and quick trips of 3 miles or so for a whole year and no problem. Then I took it on a 26 mile round trip ride and the first motor pooped out on me. I just use it as a back up bike now.
For the money it's a good bike. Would probably get many more miles at 24v stock no problem, but it's too slow for my tastes now. I saw your southpaw upgrade and like that idea a lot. Another idea to make the motor last would be to install a barbecue thermometer on the motor and lay off it when it heats up.....?

[amberwolf]

Run the BBQ therm sensor to a solenoid valve, attached to the end of the hose for a camelbak backpack. Mount the end of the hose near the motor (and pressurize the backpack or use a PC water pump instead of solenoid, and put a misting attachment on it). Or for emergency full-motor cooling, put the end of the hose *inside* the motor; it's bad for the commutator but it'll cool it off and keep it running long enough to get your ride done, as long as you don't run out of water.

[DrkAngel]

Of course, for the "innovator", the motor, alone is available!
450w 24v, gear reduction motor, standard 1/2" x 1/8" chain (MY1080Z) - $65 + shipping

Rated for 24v, but runs nicely from 12v - 36v.

"Kit" for $!00? Then add battery.

Extra notes:
Motor is capable of direct connection to DC - battery.
Gear works nicely with 3/16" chain, also.
3000 rpm w/7.2:1 reduction ratio = 417 rpm.
Sealed ball bearings, easy to lubricate reduction gears.

"Related items" same listing:
"Universal" mounting bracket available - $10
Throttle - $9
24v controller - $15.50

[neptronix]

Motor is capable of direct connection to DC - battery.

You can do that.... but you'll get unlimited amps, which will beat the hell out of the battery and beat the hell out of the motor during acceleration and hill climbing duty.

I wouldn't call that an option or even mention it really without mentioning the fact that an unlimited current will destroy things.

[DrkAngel]

100 amp T-Plug connector (Dean's Plug)
Reliable connection, but might possibly separate if snagged on brush ... Duct tape solution?

Makes rear wheel work, extremely simple.
For "Standardization", I cut the wire 2 1/4" from the motor.


Reliable source:
New Red Nylon T-plug Male/Female 5 Pairs(10 pcs)- $3.99 + $2 shipping
Fast shipping & confirmed stable under soldering temperature.

[Zen_Shenron]

Previously, it has been possible to buy the entire EZip bike for around $300, sadly, haven't seen anything near that, in almost 1/2 a year.
Present prices are in the $500 - $600 range.
Possibly some clearance items, come Fall, when sales slow down?

I just managed to pick up one at my local Pep Boys for $399. It was apparently marked wrong . As my first entyl level e-bike I am happy to have gotten it so cheap, as I was saving for one of the Amped-Bike kits. I have already ordered the southpaw freewheel for the mod you have suggested, and another battery pack which I am thinking about wiring in parallel to give it more ah.

My initial impression of the bike is its very heavy, having come from aluminum frame mountain bikes(non-electric). Also without using the motor its like pedaling thru molasses in winter, which I hoped will be fixed by the freewheel upgrade. Overall I think it is a good beginners bike but I am already planning my first real e-bike project, but that will be awhile before I get started with it.

[dumbass]

Yes an Ezip is heavy but only about 10# more then a steel bike. The freewheel with give a higher top speed but it doesn't change how it feels to peddle. In fact it will make it feel even heavier because the torque of the motor will be significantly lower.

Bob

[DrkAngel]

16T freewheel upgrade will allow 25% more motor speed, with the loss of 20% torque.
The oem freewheels turn "hard", like they are filled with tar.
Pedal alone, is much easier with the Southpaw.

Also, check tire pressure, 70lb recommended for best rolling.

Lift bike, spin tire, look for brake contact.

Before changing freewheel, spin rear by hand, and check time, till stop.
Compare to new freewheel!

[dumbass]

16T freewheel upgrade will allow 25% more motor speed, with the loss of 20% torque.
The oem freewheels turn "hard", like they are filled with tar.
Pedal alone, is much easier with the Southpaw.

Also, check tire pressure, 70lb recommended for best rolling.

Lift bike, spin tire, look for brake contact.

Before changing freewheel, spin rear by hand, and check time, till stop.
Compare to new freewheel!

Not to start another argument but I don't see how your #s can be correct. I know you have done this mod more then once. So I do not question that you increase your top speed from say 16mph to 20mph (your stated 25%). But to only lose 20% torque seems very low to me. While I have not tried to run the numbers but based on the the significantly increased load on the motor I would think it would be more in the 30% to even 40% range. And BTW, this added load also increases the amp draw on the undersized crap battery pack (yes, I know you don't normally run the stock packs but many do). I think the mod is great and simple for those wanting more speed and can afford a better pack. But personally if speed isn't an issue I think the lose of even 20% torque on this under powered bike is a big lose especially if a person has limited peddling ability. Just my opinion.....

Bob

[neptronix]

+1; efficiency takes a dive due to the motor staying at lower speeds for longer. If you overextend the gear ratio on an electric motor, you do risk overstressing it.. keep in mind that this is a very small motor and can't handle a lot more power continuously than stock.

If you had hills like i have where i live, you would toast that motor, and/or it would not even make it up the hill in the first place.

I had a 450w currie lead sled and it was horrible on hills, almost useless. The motor would get very hot on hills... don't leave you hand on it for more than 1 second hot . That's on stock voltage with sagging lead acid batteries.

Now you know why i come on here and talk smack about the currie setup.

If you baby it and don't have much in the way of hills, you may as well just pedal a regular bike anyway.
( I feel the same way about those 250-350w geared motors btw )

[gogo]

If you baby it and don't have much in the way of hills, you may as well just pedal a regular bike anyway.
( I feel the same way about those 250-350w geared motors btw )

I'll take any assistance I can get and "feel" good about it.

[neptronix]

Where i draw the line is when the assistance doesn't make up for the added weight.

I go 15-20mph constant on my roadbike, so honestly an eBike that goes up to about that speed is useless to me.

Ride an unpowered eBike up a hill and you will realize that a lot of the work that a low power motor does is move it's own motor and battery weight + mechanical drag.

Once you ride a higher power bike, there is no going back to < 500w.