if you think helical makes no noticeable difference to power, their is a good example on the currie motors
http://endless-sphere.com/forums/viewtopic.php?f=28&t=33816&start=25
For the older MY1018z with strait cut gears and the the newer XYD-16 with helical gears.
Both motors are the exact same size and the only difference is the gearbox teeth.
So yes helical is quiet but that comes to a bit hit in power and efficiency that is definitely noticeable.
http://endless-sphere.com/forums/viewtopic.php?f=28&t=33816&start=25
For the older MY1018z with strait cut gears and the the newer XYD-16 with helical gears.
Both motors are the exact same size and the only difference is the gearbox teeth.
Postby veloman » Tue Sep 04, 2012 2:50 pm
What makes the newer currie motor less powerful? It's the same size I believe. I just picked up a cheap ezip ecoride on craigslist, for the quiet currie motor on it. I plan to either add it on my main 9c ebike, or do a lightweight build with it as a mid drive to the front chainrings like my old ebike builds.
Re: Currie-EZip ebike Kit $289.88 - Amazon.com
Postby DrkAngel » Fri Jul 22, 2011 1:32 pm
I finally had a chance, to take a good look at the motor on my latest EZip.
I felt it to be different for 2 reasons.
1. It seemed to have slightly less power, than earlier motors.
2. It was, comparatively, extremely quiet.
Closer inspection revealed it to be a totally different motor.
Previous models used the MY1080Z motor.
This model used the XYD-16 motor. Top speed, with the XYD-16, is approximately 10% slower, than the previous MY1080Z model.
21mph, motor only, cruising speed vs 23mph. (25.9v Li-ion w/16T modded)
by neptronix » Sat Aug 13, 2011 7:59 pm
The helical gears are what's reducing the noise, half of the noise that the older eZips produces is gear noise alone.
Helical gears are less efficient. That could be where you are losing your power
So yes helical is quiet but that comes to a bit hit in power and efficiency that is definitely noticeable.