Q128H Light & Torquey 800W Hub Motor

[killerisation]

The new motor that should be mentioned in this conversation is the Shengyi SX. It looks like it is similar to the Q128 but with higher efficiency. Anyone have any further data to compare?

 

[neptronix]

All data i've seen on the Shengyi motors shows that they've got good efficiency in small to mid sized geared motors.

The model that ebikes.ca calls the SX2 has something like a 87% peak efficiency and only uses one set of gears to achieve that.
That's more impressive than most dual reduction systems.. both in terms of power density and efficiency.

 

[jbell]

On the 8% hill and a weight of 110kg 36N-m should do it at 14.5mph, and that is not including any pedal power. The Q128H motor chart
View attachment 244182
says 680W shaft power out and 880W electrical power in, 200W heating the hub. It will be interesting to see how closely reality comes to the predictions.

resurrecting this thread - as I want to do similar. I bought a 36v201rpm, running at 48v, KT25 C5=4,C14=3 to keep all pas under 800watts. How did this turn out on your commute?