Re-gearing the eZips - Simple Mods!

[DrkAngel]

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.

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".

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.

 

[DrkAngel]

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))

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.