A couple of questions about Q100 vs Q128H/CST Hub motor

[leelorr]

Hello,

I am thinking of building my second E-bike (the first was a BBS02 750w mid drive) and I am thinking of experimenting with a stealthy sine wave hub motor build for a change. I have read many posts here about the Q100 and Q128 hub motors for low powered use and have a couple of questions:

1. I have read in a few posts that the Q128 motors are much noisier than the Q100 motors. Is this true? If so, is it because of the greater internal gear reduction in the Q128 motors? The Q100 motors are only rated for 350 watts, hence the interest in the Q128 instead.

2. I am thinking of converting a mountain bike that currently has a seven speed rear derailleur, which should be compatible with a Q128H freewheel motor in 135mm. I am interested in using this motor if possible because it is rated for 800 watts instead of the Q128CST's 500 watt rating. I have read that the "freewheel" motor versions have much worse gear shifting behavior. Is this true?

Thanks for your help,
Leelorr

 

[Ykick]

Check my sig link for couple 700c city builds using the Q128H 800W 201 RPM. The Schwinn used 7 spd freewheel and trigger shifters and shifted fine.

A little dishing was required (I laced the motors) but it wasn’t severe enough to need all inside/out spoke direction around the flange.

We threw between 800-950W, 60-66V at these motors using Lyen sensor 6 FET controller. Top speed level flat was about 22-24 MPH.

They were running great for a few months but eventually clutches started chewing spring material and needed frequent repairs. Eventually, some of that material found its way into the gears and put that motor out of service for a long time.

I also believe the speed we ran at was a problem for the white gears. If you ever do med-fast runs longer than a few miles without stopping the heat will catch up to the white nylon gears.

Alluring little motors but gotta be much more gentle with ‘em than I’m used to running 13-16lbs DD hub motors.

My next foray into geared hub motors will be something at least using composite gears. And, in a perfect world, a reasonable and reliable source to buy more?

Oh, one last thing - there's supposed to be "new" designs so what I've experienced may no longer apply. Good luck...