Seemingly this might sound like I am taking a big step backwards ...
I intend on negating all my regearing upgrades by putting the oem 20T motor side freewheel back on my 2009 eZip Trailz LS.
Although I am joyfully satisfied with the 3 years and 6000+ miles from my little Comfort Cruiser@25.9V w/16T mod, I gotta try some new ideas.
Reasons:
1. I have never run this bike by pedal only, so the stiff oem freewheel will not "drag me down".
2. 33.3V 31.2Ah of 18650 cells will squeeze into the oem eZip battery case.
3. The disadvantage of the 16T mod is the 20% torque loss at low speed. 100% x 16T/20T = 80% torque.
The advantage of 33.3V is 100% x 33.3V/24V = 138.75% torque.
138.75% / 80% = 1.734375% torque or a near 75% torque increase, over the 16Tmod, while maintaining the same 20mph speed!!!
4. With the oem 9T-20T gearing this will give me the USA "legal" 20mph.
OEM speed @24V is ~15mph. 15mph x 33.3V / 24V = 20.8125mph.
5. 450w x 33.3V / 24V =
624.375w motor output.
18 - 20mph level cruising speed, my typical mode, will not add any additional stress or heat to the motor!
Acceleration to cruising speed will, tho I intend on employing my present method of pedal assisting with moderated throttle.
Hopefully, hills might not be as damaging as imagined.
Maintaining a higher, more efficient motor speed, combined with a shorter duration "climb" might offset the greater watt throughput?
My purpose is to modify-improve ... while still maintaining "legal" status.
This looks to push the eZip as far as possible? ... affordably!
Well ...
37V with a 22T motor freewheel (Staton-inc.com)?
450w x 37V / 24V = 693.75w ... Maybe?
OEM speed @24V is ~15mph. 15mph x 37V / 24V = 23.125mph.
23.125mph x 20T / 22T = 21.022mph ... hmmm ...
Oh!
Rather than trying to straighten my 16T mod "bent" motor bracket, I intend on using my 12G spoke modded wheel and bracket, tho I might keep the "quiet" XYD-16 motor (6000 mile veteran).
I do have 1 super HD "Electric Bicycle" tire.
Might sell entire project to a 300lb+ acquaintance ... after testing of course.
33.3V Sanyo 18650 cell pack will be charged to 4.05V per cell.
Capacity mapping indicates this as being optimal voltage for good capacity ...
with ~300% usable life!