Re-gearing the eZips - Simple Mods!

DrkAngel

1 GW
Joined
Dec 15, 2010
Messages
5,300
Location
Upstate-Western-Southern Tier NY. USA
Prologue:
For the most part, I intend these upgrades as being designed to meet the USA "legal" 20mph speed.


Most members wonder at my eZip fixation.
I admit ... the oem eZip is a cheap, heavy, lackluster eBike , but ...
It is so simple to upgrade-enhance. Different inexpensive mods greatly enhance its capabilities.
But , for now, I just wanted to consolidate the re-gearing mods (did not list the lower gearing)

More speeed!

OEM
The eZips, Trailz etc., have an oem 15-16mph capability, with some slight assist to ~18mph.

eZip 22T Freewheel Mod
Replacing the oem 20T freewheel with a 22T freewheel.
To lower speed for more torque, hills, heavy load etc.
Limits speed to < 20mph when combined with 33.3V battery.
Designed for heavier loads and hilly territory.

16T ACS Southpaw Mod - $20
Simply replacing the oem 20T motor side freewheel with an ACS SouthPaw 16T.
This increases speed to ~20mph, a 25% increase.
Torque is reduced 20% at 0mph, but loss decreases till torque actually increases at above 10mph!
Also, much more efficient! reduces motor drag during pedal only!

11T Motor Sprocket Mod - $18
The ideal eZip upgrade!
Simply loosen, replace 9t with 11T, re-adjust - tighten chain = nearly 20mph ("legal) limit.

12T Motor Sprocket Mod - $24
A "simple" re-gearing.
Merely replace the oem 9T motor sprocket with the 12T.
This will give you a 33.3% speed increase.
A reasonable expectation of 20mph - motor only.
With some assist to 24mph.

13T Motor Sprocket Mod - $18
Plug-n-Play! Good fit, good alignment ... just build longer chain.
My 22.2V 41.6Ah prototype might push to 20mph with the 13T alone!

15T Motor Sprocket Mod - $12

A "simple" re-gearing.
Merely replace the oem 9T motor sprocket with the 15T.
This will give you a 66.7% speed increase.
A substantial assist of 25mph - motor only? ... possibly.
With some assist to ~30mph.


Re-gearing mods might require differing length chain!

9T - 22T requires 15 - 2T links (22T mod) near max adjustment - encourages replacement when chain stretches-wears
9T - 20T requires 14 - 2T links (OEM)
9T - 16T requires 13 - 2T links (16T mod)
11T - 20T requires 14- 2T links (OEM)
13T - 20T requires 15 - 2T links (13T mod)

(16T combined with 13T might use OEM chain?)


See also - Re-volting the eZips - Simple Mods!
 
Of course ... you could add a 12T or 15T mod to the 16T ACS mod.

But you must expect to provide substantial pedal assist, or you are liable to be sadly disappointed.

16T + 12T = 25mph (Some assist till 30mph)

16T + 15T = 30mph? (Some assist till 37.5mph)
Might be victim to a negative return on speed! (motor only)
Ideal for the cyclist capable of constant and substantial pedal assist.
Even with the 11T 7speed freewheel, assist past 30mph would require upgrading the front chainring from 44T to 48T ... 52T? Simple upgrade.
 
13T motor Sprocket Upgrade - $18 just surpassed the 16T Mod as the best, cheapest, easiest mod!

R0054065.JPG


Also requires longer chain.
 
Pulled the trigger and ordered this sprocket (from China?). Hope it gets here soon, my new Trailz is due to arrive at weeks end. Will I need any special tools for installation? Thanks...
 
I would be remiss in my endeavors if I failed to investigate the potential of re-voltaging the eZips.
So, if you would like to see some of my alternate projects, see - Re-volting the eZips - Simple Mods!
 
A representation of the torque and projected speeds attainable with the various mentioned re-gearing mods.

Note - Speed-Torque lines are for gearing ratio comparisons and do not represent "torque curves".
24V Re-Gearing Modss.JPG
While I have previously mention an 11T mod the available component requires too much work to be "reasonable", in my opinion.
The 16T freewheel mod supplies a pedal alone 20mph with a minimal loss in low speed torque.
Ideal for the average to handicapped-feeble cyclist. (eBike - electric bike)
At the opposite end, the 15T mod, while it suffers a severe loss of low end torque, it supplies a motor only ~23mph with some degree of assist right to 30mph.
OK for the average cyclist, but best for the cyclist willing to pedal getting up to speed and appreciative of the assist past the point of motor only capability. (eaBike - electric assist Bike)
 
And ... for the hardcore cyclist ... a 16T & 15T combo mod.
With upgraded front chainring, might be 30mph + sustainable!

Note - Speed-Torque lines are for gearing ratio comparisons and do not represent "torque curves".
24v geared ups.JPG
 
DrkAngel said:
And ... for the hardcore cyclist ... a 16T & 15T combo mod.
With upgraded front chainring, might be 30mph + sustainable!
I am not running your bike but the chain ring 60t with 16t for high gear is spot on. It will do 30+ mph easy on a 24" tire. Now you do need to watch your bike weight. I pedal all the time but 50% of the time I do 100% assist. I don't think your feeling the amount of wheel weight my geared 500w hub motor gives me due to the design of your bike. The flywheel effect is good and bad. When you take off its bad but good when staying at one speed. I think we sometimes talk about only the electric part and don't talk about the total system.
 
emiyata said:
DrkAngel said:
And ... for the hardcore cyclist ... a 16T & 15T combo mod.
With upgraded front chainring, might be 30mph + sustainable!
I am not running your bike but the chain ring 60t with 16t for high gear is spot on. It will do 30+ mph easy on a 24" tire. Now you do need to watch your bike weight. I pedal all the time but 50% of the time I do 100% assist. I don't think your feeling the amount of wheel weight my geared 500w hub motor gives me due to the design of your bike. The flywheel effect is good and bad. When you take off its bad but good when staying at one speed. I think we sometimes talk about only the electric part and don't talk about the total system.
26" with heavy 2.125" "Electric Bicycle" tire, add a 5x thickness slime tube and my first time trying to turn at 30mph was a bit "surprising".
All the extra weight is around the outside, which amplified the "gyroscopic" affect.
 
DrkAngel, a friend has a Currie bike and got a 24v duct tape battery for it. Upon hooking up the wiring, with an inline fuse, it will go about a 100 ft. and then shut down. If he takes out the fuse and puts it back again it will do the same thing. I am thinking it is a controller issue but am not familiar enough with the Currie system in regards to the controller? Any help appreciated and thanks in advance! (also posted on bikeforum)
 
mabman said:
DrkAngel, a friend has a Currie bike and got a 24v duct tape battery for it. Upon hooking up the wiring, with an inline fuse, it will go about a 100 ft. and then shut down. If he takes out the fuse and puts it back again it will do the same thing. I am thinking it is a controller issue but am not familiar enough with the Currie system in regards to the controller? Any help appreciated and thanks in advance! (also posted on bikeforum)
Battery pack with built-in BMS?
Small pack? 10Ah? Might be over taxed by 35Amp Currie controller.
BMS "faults" and is reset by resetting fuse?
Try limited throttle, or PAS mode, as diagnostic.
 
DrkAngel said:
mabman said:
DrkAngel, a friend has a Currie bike and got a 24v duct tape battery for it. Upon hooking up the wiring, with an inline fuse, it will go about a 100 ft. and then shut down. If he takes out the fuse and puts it back again it will do the same thing. I am thinking it is a controller issue but am not familiar enough with the Currie system in regards to the controller? Any help appreciated and thanks in advance! (also posted on bikeforum)

Battery pack with built-in BMS? It doesn't sound like there is a BMS.

Small pack? 10Ah? Might be over taxed by 35Amp Currie controller. Not sure of the ah, and the owner could not remember....., but it is not very big physically, 9x5x3 so I would guess that it isn't over 10ah.

BMS "faults" and is reset by resetting fuse? N/A

Try limited throttle, or PAS mode, as diagnostic. This is an older bike and the "throttle" apparently is just a switch that turns the motor on and off when it is released so there is no way to limit it. No PAS mode.

I have seen this bike before but unfortunately it is not close enough to me that I can go take a look for myself and I can't remember it well enough. So I am stuck trying to help via phone conversation with my friend. It is actually a Currie brand bike though and as I said an older model. I can't seem to get him to locate a controller?

Thanks for your help!
 
Made of a graph with the mods for my favorite voltages demonstrated.
Terminal Velocity is a realistic top speed for a typical mountain bike. (Wind, and road, resistance factored in.)
Just added terminal velocity for Race Bike Tuck.

Note - Speed-Torque lines are for gearing ratio comparisons and do not represent "torque curves".
high speed.jpg

25.9V is the closest to oem and works on every eZip I've run into.
33.3V is a simple upgrade that works with some older eZips or with a 36V controller, and limits additional heat production.
44.4V is a substantial upgrade and can produce damaging heat, runs from a 48V controller. Either throttle restraint at lower speeds or a reduced amperage controller should reduce potential damage.
 
For future reference ...
Terminal speed was referenced to 50mph.

Note - Speed-Torque lines are for gearing ratio comparisons and do not represent "torque curves".
Terminal Speed.jpg
http://ebikes.ca/simulator/ was used as the terminal speed reference.
 
gngebike.com now stocks 8T, 9T, 11T, and 13T sprockets for the eZip motors!
These sprockets are a plug-n-play fit, no mods necessary ... except for chain length ...
For the 1st time there is a smaller = more torque, 8T sprocket available. (88.88% speed & 12.5% torque increase)
8T combined with 33.3V might match 20mph "legal" USA specs?
(36V controller upgrade required for newer eZips)



In the past I have received shipping discounts by requesting combined shipping of multiple items. (multiple sprockets)
 
I've been running a 13T mod for several 100 miles.
It provides a great speed increase with the eZip oem 24V SLA batteries. - right ~20mph

However, with my 25.9V Lithium upgrades ...
The 13T pushes pushes my eZip towards 22-23mph.

Ok in some ways ...
22mph+ motor only and some assist past 25mph is fun!

But ...
It exceeds the "legal" 20mph.
and
With my homemade (laptop cell) lithium batteries, it exceeds my recommended .5C cruising drain.

So ... I have decided to try a 11T mod,
Object is to produce a 20mph motor only "legal" speed from my 25.9V lithium batteries.
Range and battery life are expected to increase noticeably.

The newer eZip have a better quality and removable 20T freewheel, making the 16T mod ... not as attractive.
And likely-hopefully the 11T mod can use the oem chain! ... ?
Making it the simplest-easiest 20 mph mod (25.9V battery required)

Note - Speed-Torque lines are for gearing ratio comparisons and do not represent "torque curves".
9-11-13T.jpg
 
Do you know of any good chain rings that are bolt on for the Currie Ezip Trailz?
 
Graphs showing Torque-Speed profiles for the eZips @ 25.9V.

Note - Speed-Torque lines are for gearing ratio comparisons and do not represent "torque curves".
25.9V Gear Mods.jpg

Had to add 33.3V plots

Note - Speed-Torque lines are for gearing ratio comparisons and do not represent "torque curves".
25.9V vs 33.3V Gear Mods.jpg
 
Just rebuilt the rearend of my 2009 eZip Trailz LS.
I've been waiting for an opportunity to use the wheel I upgraded to 12ga spokes.
Replaced the 20T oem freewheel with the 22T freewheel I found.
Adds torque and hauling-climbing ability.
But so slow ... 13-14mph from 24V.
So, since this 2009 had a 24-36V capable controller, I pop in my 33.3V pack.
Provides a reasonable 18-19V+ cruising speed, with decent acceleration to cruising speed.

Mistakes?
Left the 32-11T DNP 7spd freewheel on ... will replace with original 34-14T Shimano.
Time to build the 33.3V 31.2Ah battery, with the NOS cells I've been saving.
I got more of the 24-36V capable brush controllers.

Similar model 36V controllers likely has no HVC so should be 44.4-48V capable, but, has 50V caps. Just got the 63V caps for upgrade! :D
Plan on re-gearing an eZip from my spare parts pile (bought off neighbor after lady ran over front wheel and fork) for 30mph from 44.4V (33.3V for everyday).
(Got disc front fork and wheel from trash day, need to lace on new rim)
Estimate 13T-20T sprocket freewheel @ 44.4V for 30mph capability.
32-11T DNP 7speed and will likely upgrade from 44 to 48T chainring. Or ... low seat and bars with small windscreen, for motor only 30mph.
 
eZip Gearing.JPG
 
DrkAngel,

I'm happy to see you on the boards here. I used to check out your posts on a now-closed ebike forum back in '09 when I first got my E-Zip Trailz. I have since moved all of the components (except battery rack) to a lighter frame and I'm running 36V via 3 SLA's. I recently did the 13T motor sprocket upgrade. I got a big boost in speed :D . However, a sometimes wobbly rear wheel finally bit the dust last week. :( One of the inner races for the bearing just sheared itself completely, and the bearings rolled out.

I took it to a bikeshop-owner friend, and he said he could not repair it - mostly due to not being able to source the lefty freewheel. I have since found the freewheel unit as well as a whole new rear wheel.

In your opinion, do you think that the stock hub can be rebuilt with a new replacement freewheel (approx $25 for the part) or, do you think I will need to buy a whole new rear wheel (about $100)?

Thanks for your reply, and I'm welcome to other opinions for ES posters.
 
Bike2Bus said:
DrkAngel,

I'm happy to see you on the boards here. I used to check out your posts on a now-closed ebike forum back in '09 when I first got my E-Zip Trailz. I have since moved all of the components (except battery rack) to a lighter frame and I'm running 36V via 3 SLA's. I recently did the 13T motor sprocket upgrade. I got a big boost in speed :D . However, a sometimes wobbly rear wheel finally bit the dust last week. :( One of the inner races for the bearing just sheared itself completely, and the bearings rolled out.

I took it to a bikeshop-owner friend, and he said he could not repair it - mostly due to not being able to source the lefty freewheel. I have since found the freewheel unit as well as a whole new rear wheel.

In your opinion, do you think that the stock hub can be rebuilt with a new replacement freewheel (approx $25 for the part) or, do you think I will need to buy a whole new rear wheel (about $100)?

Thanks for your reply, and I'm welcome to other opinions for ES posters.
If you find a die to thread it ... ?

I lost 2 hubs to same race failure ...

Cheap replacement hubs are available - eZip rear hub replacement $19.99 shipped
attachment.php


But requires 262 & 264mm spokes (eZip oem are 258 & 260 = will not fit!)
Seems threads are very tight.
I haven't tried to torque freewheel totally on yet ... might notch old freewheel (makeshift die) and cut threads better?

Replacement wheel should be an iZip, with better alloy hub!

See also - Broken Spokes - Solutions!
Multiple solutions for the EZip - IZip broken spokes problems!
 
DrkAngel said:
I lost 2 hubs to same race failure ...

Cheap replacement hubs are available - eZip rear hub replacement $19.99 shipped
attachment.php


But requires 262 & 264mm spokes (eZip oem are 258 & 260 = will not fit!)
Seems threads are very tight.
I haven't tried to torque freewheel totally on yet ... might notch old freewheel (makeshift die) and cut threads better?

Replacement wheel should be an iZip, with better alloy hub!

See also - Broken Spokes - Solutions!
Multiple solutions for the EZip - IZip broken spokes problems!

Thanks for the link to the hub listing (8 units offered are currently sold out). Is it possible that If I get this new hub and new spokes, but keep my old stock rim that it will work? Or are you saying that I will have to also get a whole new rim to be compatible with the required new spokes for this combination? If so, do you have a rim suggestion?
 
OEM 36H rim is OK.
 
Similar item available - L\R Hub - $25


$_57.JPG


No ... use the oem or ACS left hand freewheel ...
Ummm ... large motor sprocket might be bolted to 16T or 20T usable left hand freewheel?
 
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