Re-gearing the eZips - Simple Mods!

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DrkAngel
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Re: Re-gearing the eZips - Simple Mods!

Post by DrkAngel » Nov 10, 2014 6:17 am

Motor alone, there is always a maximum speed limitation
For example:
A 450w eZip motor, pushed to 25.9V can output 485w.
485w can provide about 22mph on a mountain bike, 26mph on a race bike.

Image
But only with optimal gearing ...

Gearing too high will actually start lowering motor only speed!

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

Gearing higher will lessen motor assist for climbing hills and getting up to cruising speed but provide better assist above 23mph for your substantial pedal power.
Sacrificing motor only torque and speed to gain motor assist at just above motor only limit.
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User avatar
DrkAngel
10 GW
10 GW
Posts: 4470
Joined: Dec 15, 2010 11:14 am
Location: Upstate-Western-Southern Tier NY. USA

Re: Re-gearing the eZips - Simple Mods!

Post by DrkAngel » Nov 23, 2017 1:48 pm

Well 24V 450w 16mph eZips have been out of production for a few years now.
Time to drag them out of the garage and breathe new life into them!

Re-gearing and Lithium power can make them actually respectable!
Replace the 20T wheel freewheel with the 16T, and 24V will deliver 20mph.
Upgrade to 25.9V Lithium and cruise at 21mph. (485w motor output)
Upgrade to 37V Lithium and cruise at 27mph, with sustainable pedal assist pushing to 30mph! (~725w motor output)
.
(H3540 motor was chosen for nearly identical power profiles. Tire size emulates gearing))
eZip gearing perfected.jpg
eZip gearing perfected.jpg (221.83 KiB) Viewed 55 times
At top speed, with geared and volted for 20 or 30mph, efficiency is optimal. (80% efficiency)
20mph (21mph+ actual) geared has a nice reserve of power starting into hills, additional 150w of power as speed drops to 20mph.
30mph (27mph actual) geared has full assist till 30mph. 250w pedal assist or racing posture allows sustained 30mph.
A little learning is a dangerous thing;
Drink deep, or taste not the Pierian spring:
There, shallow draughts intoxicate the brain,
And drinking largely, sobers us again.

I enjoy enlightening ... and enlivening the spirit of the innovators.

New & Improved - Acronym Definitions

Index - Homemade Battery Packs - Updated - November 2015

EBike Toolbox - Bargains! $

Endless Sphere Wiki

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