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EZip - IZip 20mph Upgrade $20!

DrkAngel

1 GW
Joined
Dec 15, 2010
Messages
5,300
Location
Upstate-Western-Southern Tier NY. USA
I've achieved a sustainable 20mph from a 24v battery pack.

The "stock" EZIP Trailz, Mountain Trailz also, has a typical top speed of about 16mph, with some "assist" up to about 18mph. I felt that they must have made some mistake in their concept since the USA legal limit is 20mph. I felt it my duty to try to fix their mistake!

The most reasonable, (simplest), method would be to change the motor's gear ratio.

Two methods are possible: note:T = teeth.
1. Increase the size of the motor drive sprocket, OEM is 9T, 11T would be about right. 22% increase.

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2. Decrease the size of freewheel on the rear wheel, OEM is 20T, 16T would be perfect.



After an exhaustive search, I was unable to find, any compatible motor sprocket, anything close required, modification, custom adapters, machining, or all 3.
Edit - Compatible motor sprockets11T and 13T have been found! See - eZip motor sprockets
Took me quite a while but I finally found an acceptable 16T freewheel. The difficulty is that it must have a Left-Hand thread, comparatively rare. After a few "wrong" purchases I finally came across the: ACS (manufacturer), Southpaw (model), 1/2" x 1/8" x 16T freewheel. Perfect, (well almost).

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Going from a 20T to a 16T would increase top speed , from 16 MPH up to 20MPH, a 25% increase, "torque" however, would be lessened by 20%, requiring more pedal assist on, the same, hill climbing.

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Instructions:

Parts:
1. ACS Southpaw 1/2" x 1/8" x 16T freewheel.
Note: 14T is also made, but, will not fit!

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2. A "single speed" chain repair link.

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Special tool:
Small grinder - Dremel tool with small grinding wheel, or similar.

Step 1
Remove motor. I securely taped it to the battery rack.
Loosen motor mount bracket, 2 adjustment & locking bolts.

Step 2
Remove rear wheel.
Place bike, upside down, or on side, and loosen 2 rear nuts. Remove wheel, an extra pair of hands is helpful, managing chain, etc. Careful you don't pinch or mash your friends fingers! - Now comes the hard part.

Step 3
Remove the freewheel.
Edit - Some 2010, and newer eZips use an easily removable freewheel = standard freewheel removal tool
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Method 1

The OEM freewheel is designed as cheaply as possible, which means, no notches for removal, hence the grinder.
The freewheel is loosened by turning in a clockwise direction.
There are 2 indentations, designed for a spanner wrench, but only suitable for the original install. You can try, but wear gloves to protect you fingers, and place something on top of spokes to protect them.
I ground 2 opposite side notches and used a freewheel wrench to remove. Any method that lets you get a grip on the, non-spinning, center, is acceptable. 2 synchronous tapping with hammers & screwdrivers might work. My method let the freewheel survive, just in case.


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Method 2


Works on "new" unused, possibly slightly used, freewheels!
Personally have removed 2 new & 1 slightly used.

Was able to replace freewheel with 16T, method explained.

Requires Park tool SPA-1 spanner wrench. $10 - $15 shipped.


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Most important is that wrench is securely seated and supported.


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Turn clockwise, to loosen!

Note: Stock freewheel comes, smothered in a "gruesome" green grease. Yuck!

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Step 4
Install new freewheel.
I mentioned the Southpaw was "almost" perfect...
Being a "quality" freewheel it has removal notches, unfortunately they make it slightly wider.

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Two possible solutions:
1. Seal all joints, I used duct tape, to keep grinding residue out of freewheel. Grind notches down, about half way. Remove tape and install.
2.(Recommended method!) Insert a 3/8" standard washer as a spacer, clearance is very close, 1/16" might be enough, 1/8" thicker than necessary.
Install freewheel, check for clearance, before tightening. Center nut, or washer, must rise slightly above freewheel.
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Step 5
Shorten chain, by 1 link, this would be 2 segments. Remove 3 segments and install repair link. I've done similar with hammer & screwdriver, or 2 pair pliers. Chain breaker, works perfect, any bicycle shop should do the job for you very cheaply. Get them interested in the project and they might jump at the chance to help, with the whole project.

Step 6
Reassemble.

Don't worry if you forgot to put the motor chain back on, open the link, install, close link.

Done!

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Fresh battery - 65lb tire pressure - full throttle - level road = 20 mph. Tested on slight downgrade and confirmed, some assist through 22mph, slowed down when throttle released.

Added Bonus!
OEM freewheel is very stiff, even after being "broken in".
Southpaw spins easily.
Like stirring a pot of grease, compared to stirring, a pot of water.
Which means ... pedaling, without motor assist, is less work, more work goes to the wheel, less to the crummy freewheel!

Will add pictures and updates.

EZip Engineering 101
 

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Excellent re-engineering job with a fine description and photos.

I don't know for sure yet if I'll follow your lead, but you've done a nice job of blazing the trail and it'll be helpful to anyone of us who do go for it.

Thanks.
 
Hi DrkAngel-

I have seen your post in other website called ecowheelz forum. Good work!

How about hub geared iZip, I am trying find right controller that will allow me upgrade to 36v since the current
24v controller wont let me plug in with 36v.

Since the eZip trailz older version controller able run either 24v or 36v without any necessary upgrade.
 
Hi Darkangel..
Top upgrade nice work..
Are you still running 36v?? and if so how are your brushes holding out..
I have an Ezip Trailz with the standed 200 watt motor..
And I also own A Curry Dyno CB 24v200..
I have switched the 200 motor for a 450 watt motor from
http://secure.oatleyelectronics.com//product_info.php?products_id=811&osCsid=def42d5781cd40ba6ac33791b5ad034a

and gained 8 kph on the Curry Dyno increased from 20 kph to 28 kph..
I have just ordered the Southpaw 16 tooth Freewheel from

http://www.pricepoint.com/detail/16670-065_ACSCL7-3-Parts-51-Cassettes/ACS-Claws-Freewheel-3/ACS-Claws-Freewheel-3_32.htm

Thank you from posting your upgrade.. I am still running the original 2x12vx 12ah sla's over 4 yr old now due for an upgrade to 3 of these

http://www.hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=14716

Will give 29.6V at 17.4 ah hopefully it wont be to over volted and a possible 45kph..

Regards John
 
2 Ezip MT@37v (homemade Li-ion) and 1 EZip Trailz@25.9v (homemade Li-ion). Did the 16T upgrade on 2, left one MT at 20T for more torque, through the winter - ice, snow & slush (homemade studded tires).
Also upgraded the 7spd freewheel to various 11-28,32,34T. The 11T allows pedal assist right up to 30mph!

I've put more than 6000 miles, at 36v, on 2 EZips. No overheat or brush problems. I lube the motor, gear section twice annually. Only motor problem seems to be on my "Winter" bike, brush end, "sleeve"? bearing seems to make a bit of a squeal during first engagement, on cold mornings
 
Has anyone done any brake pad upgrades to the ezip? The rear frame has extra wide pads because the frame width is wider then normal mountain bikes. The extra wide pads are u-brake type. Normal width pads installed won't be able to be adjusted right. I've found the front brakes work great, but the rears suck. And it might be that the leverage of the brake arms just suck and the pad is ok.
 
I've put more than 6000 miles, at 36v, on 2 EZips. No overheat or brush problems. I lube the motor, gear section twice annually. Only motor problem seems to be on my "Winter" bike, brush end, "sleeve"? bearing seems to make a bit of a squeal during first engagement, on cold mornings

Thank you DrkAngel ..
That's great I won't hesitate I will go straight to 36V then :)
John
 
jmack said:
Thank you DrkAngel ..
That's great I won't hesitate I will go straight to 36V then :)
John

I've heard plenty of stories about these motors overheating and burning up, some have gone to great trouble to add extra cooling.

I've ridden thousands of miles with no overheat problems, probably because:
I always pedal, w/motor, from a stop, till at cruising speed.
I always attack a hill, accelerating before hill and pedal hard to maintain speed, reducing throttle as speed decreases.

Heat is the enemy!
Electric motors have a range of efficiency.
For example, full throttle from a dead stop might produce 10% power and 90% wasted, (damaging), heat.
A 24v EZip motor, (top speed 16mph), seems to be most efficient in the 8-12mph range at full throttle, at 36v, in the 12-18mph range. Logically then, 1/2 throttle would be best, for the 4-6mph range. With a 36v set up, most Torque Per Watt, (TPW), would be throttle 1/3@ 5mph, 2/3@10 mph and full@15mph. Above this optimal TPW range, power usage is reduced, but a growing percentage is used to maintain drive train speed, not put on the road.

36v full throttle Amps used at:
1mph>30 (tested with 30amp replacement fuse, blows quickly)
15mph=15
20mph<10

How to burn up your motor?
Full throttle up a hill at less than 5mph.

Personally I would not classify the EZip-Izips as electric bikes, but rather as Electric Assist Bikes. Motor output is rated at 450w. This is, about the equivalent to the capability of a "fit" biker. In other words it is approximately equal to a bikers pedal ability. But as an EABike, pedal & motor, it becomes a power house, I typically blow cars away, from a red light, takes them 1/2 a block to catch up with me.

I first bought an EZip 3 years ago because my heart and body were in such bad shape I couldn't ride a normal bike. With practice, and the determination to pedal constantly, as my health and fitness increased, I upgraded the top speed and pedal capability to continue challenging myself.

With 37v & re-gearing enhancements 1 of my present bikes is capable of cruising at 27mph, and 30mph+ with my help, on the pedals!

Dr Kangel - 50+ and getting younger every day!
 
I've heard plenty of stories about these motors overheating and burning up, some have gone to great trouble to add extra cooling.

I've ridden thousands of miles with no overheat problems, probably because:
I always pedal, w/motor, from a stop, till at cruising speed.
I always attack a hill, accelerating before hill and pedal hard to maintain speed, reducing throttle as speed decreases.

Heat is the enemy!
Electric motors have a range of efficiency.
For example, full throttle from a dead stop might produce 10% power and 90% wasted, (damaging), heat.
A 24v EZip motor, (top speed 16mph), seems to be most efficient in the 8-12mph range at full throttle, at 36v, in the 12-18mph range. Logically then, 1/2 throttle would be best, for the 4-6mph range. With a 36v set up, most Torque Per Watt, (TPW), would be throttle 1/3@ 5mph, 2/3@10 mph and full@15mph. Above this optimal TPW range power, usage is reduced, but a growing percentage is used to maintain drive train speed, not put on the road.

36v full throttle Amps used at:
1mph>30 (tested with 30amp replacement fuse, blows quickly)
15mph=15
20mph<10

How to burn up your motor?
Full throttle up a hill at less than 5mph.

Personally I would not classify the EZip-Izips as electric bikes, but rather as Electric Assist Bikes. Motor output is rated at 450w. This is, about the equivalent to the capability of a "fit" biker. In other words it is approximately equal to a bikers pedal ability. But as an EABike, pedal & motor, it becomes a power house, I typically blow cars away, from a red light, takes them 1/2 a block to catch up with me.

I first bought an EZip 3 years ago because my heart and body were in such bad shape I couldn't ride a normal bike. With practice, and the determination to pedal constantly, as my health and fitness increased, I upgraded the top speed and pedal capability to continue challenging myself.

With 37v & re-gearing enhancements 1 of my present bikes is capable of cruising at 27mph, and 30mph+ with my help, on the pedals!

Dr Kangel - 50+ and getting younger every day!

Thank you DrkAngel..
I am 60+ and I know exactly what its like regarding health and fitness in senior yrs...
I always pedal up before applying power from a standing start and very often use pedal assist..
All the roads in my area are pretty much level no hills...
Thank you for the advise..
I have decided to go for a Ping Life4 36V 20AH battery and the 16 tooth freewheel upgrade..
I think I will be more than happy with the results :)
John
 
DrkAngel said:
Dr Kangel - 50+ and getting younger every day! ...

jmack said:
Thank you DrkAngel..
I am 60+ and I know exactly what its like regarding health and fitness in senior yrs...
I always pedal up before applying power from a standing start and very often use pedal assist..
All the roads in my area are pretty much level no hills...
Thank you for the advise..
I have decided to go for a Ping Life4 36V 20AH battery and the 16 tooth freewheel upgrade..
I think I will be more than happy with the results :)
John
Unless your EZip-IZip is a 2008, or older, you will also require a 36v controller upgrade.
 
Good work Drkangel.

BTW, your technical writeup is top notch as well (this can be much more difficult than many of us realize).
 
Unless your EZip-IZip is a 2008, or older, you will also require a 36v controller upgrade.

I purchased both bike's 2007 I have run them both on 36V SLA's.. No problems with the controller at the time ..
A friend of mine said to be careful with over volting as I might burn out the brushes
The Currie Dyno bike I also fitted a 450 watt motor with 36V I achieved 44 KPH..
Here in Australia they come standed with a 200 watt motor...
John
 
Thanks for the writeup. Its good to see a little more modest modifications after 50+ mph bikes. This is a great cheap way to hot-rod a cheap bike for some modest performance, and alot of people could benefit from that. It's always driven me nuts because I can pedal my road bike faster than 20mph, so it kills me not to have the top-end. I'll definately have to give this a go on my girlfriends izip.

Do you have a link to the motor side sprocket?

Thanks!

Edit: I just realized that you didn't do the motor side sprocket. Thats awesome! 20mph from a new freewheel alone is really awesome. I can see alot of izip owners doing this mod. Thanks!
 
Do you have a link to the motor side sprocket?[/quo

http://www.bikeparts.com/productinfo/ACS-SouthPaw-16t-Left-Hand-Drive-freewheel-18-60381-52095.html
Or
http://www.pricepoint.com/detail/16670- ... l-3_32.htm
John

Correction...
Sorry those links are no good won't work wrong part..

This link is correct part..

http://www.ebikestop.com/acs_southpaw_16t_left_hand_drive_freewheel_18-FW1233.php
 
grindz145 said:
Thanks for the writeup. Its good to see a little more modest modifications after 50+ mph bikes. This is a great cheap way to hot-rod a cheap bike for some modest performance, and alot of people could benefit from that. It's always driven me nuts because I can pedal my road bike faster than 20mph, so it kills me not to have the top-end. I'll definately have to give this a go on my girlfriends izip.

Do you have a link to the motor side sprocket?

Thanks!

Edit: I just realized that you didn't do the motor side sprocket. Thats awesome! 20mph from a new freewheel alone is really awesome. I can see alot of izip owners doing this mod. Thanks!


http://www.staton-inc.com/store/pro...ND_threads_410H_Freewheel_Sprocket-626-0.html - Price: $15.95
 

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Park tool SPA-1 spanner wrench removal method will work with a new, or unused, EZip-IZip, however...
If the motor drive has been used for any length of time, drastic methods may be necessary.

Various methods have used vises, grinders, hacksaws, pipe wrenches, drills ... in various combinations. If daunted, please remember that spoke replacement will probably require the freewheel be removed, anyhow. Better to replace with a "real" freewheel, that is easy to remove!
Simpliest method used a strong vise, to bend freewheel outer ring, tight against inner ring, then turn wheel clockwise.

The good news is that upgraders have reported that some of the newer models have a proper, easy to change, freewheel.
 
EZip Failures!
The most common problem I've run into is broken spokes.
The good news is that Currie will send you a complete new wheel if breakage occurs while under warranty, $25 shipping not covered.
In the past 8000+ miles, I've replaced spokes approx 4-5 times.
I run at the maximum 65lb pressure, weigh 200lb and ride through the constant minefield of potholes, available in a small Upstate NY city. The severe cold of this Winter is causing the, asphalt on top of old brick streets to heave and buckle in a roller coaster fashion, this Spring will be a horror for bikers.

Anyhoo ... I found a reasonable price supplier of 12ga spokes that will fit the EZip-IZips:
http://www.staton-inc.com/store/products/Spoke_12_gage_260_mm_for_26_wheel-780-21.html - Price: $0.39 each
Hub might require holes, be resized with 1/8" bit, best nipple seating in wheel requires 3/16" hole.

EZip-IZip rear wheels use 260mm & 258mm spokes. I've created 258mm spokes by threading a nipple onto 260mm spokes till 2mm spoke is exposed, then grinding it off. Removing nipple will clean threads nicely.
 
I just did a 16T upgrade on a 2009 EZip,using the washer to provide freewheel clearance. To my surprise it developed a gear to gear misalignment, much greater than the width of the washer. (I never checked the pre-upgrade alignment ... oops!)
My trial solution was to bend the heavy bracket that the motor is mounted on. This resulted in fairly smooth chain movement. I will plan a more elegant "fix".
 
Yikes.

Bet you just put a washer/nut in the wrong place when reassembling.
I've had my eZip bike apart about 10 times and it happened to me 2 times..
 
All washers nuts etc. placed properly.

Bending motor mount bracket slightly seems to have the additional benefit of causing the motor to run more quietly! ... ???
Will monitor, and modify, as necessary.

This is the 5th EZip-IZip that I have modified and I am still learning ... thankfully!
(Not too old, or hard headed, to learn!)

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