From time to time we are asked “What is the torque of the Gocycle motor?”
Generally we don’t quote this figure or list torque on the Gocycle tech specs. The reason for this is that the torque of an ebike motor does not practically predict how much acceleration you might feel on the product or how steep a hill you could go up.
The better question and answer to compare performance between different ebikes is to ask what the rate of acceleration of the ebike; however, this can also be tricky to understand as there are many factors that affect even acceleration such as tire size, gear selection, gear reduction within the motor drive, voltage of the battery, tire pressure, weight of the rider, and most importantly, where the motor is located on an ebike – for example if it is a bottom bracket drive or a direct hub drive.
Let’s consider those last two points and let’s say we wanted to compare the acceleration or hill climbing ability of two ebikes – one with the motor fitted as a direct rear wheel hub drive and the other with a motor fitted to the bottom bracket drive in the pedal cranks. Let's also say that the wheel size of these ebikes is the same. Now if the gear selected in the bottom bracket drive ebike was a high gear at say a ratio of 2:1 (for example a 44 tooth front sprocket and a 22 tooth rear) where one turn of the pedals creates two turns on the rear wheel, the bottom bracket drive configuration ebike would have ½ the so called “torque” as the rear wheel direct hub drive ebike.
So a 40 Nm torque quoted for a direct rear hub drive motor could have higher acceleration and so called “torque” than a 60 Nm torque bottom bracket drive motor.
Now you need to consider the wheel size. All things being equal, if you have smaller wheels, the acceleration of the ebike will be greater and the so called “torque” will be greater. So for example, the Gocycle’s compact wheels generally will boost acceleration by approximately 1.6 x that of a traditional big wheeled bike.
There are many other factors to take into account in order to compare apples to apples on ebike torque. However, for the purpose of helping to offer a rough guideline, and given the Gocycle is a front direct drive hub motor configuration driving compact wheels, we could talk about an “equivalent torque rating” subject to all of the variables previously mentioned, one could probably say that the Gocycle G4 drive has an equivalent torque rating of 60 Nm (Newton meters).
Here's another interesting fact - torque density. Of course you can always make a motor with more torque by just adding more magnets and electrical windings - and that = more weight. Gocycle's torque density compared to other urban mid-drives for example is class leading. A key German branded performance urban mid-drive system quotes an equivalent torque of 50 Nm and a weight of 3.2kgs - so a torque density of 15 Nm / kg. Gocycle's G4 drive torque density is approximately 25 Nm / kg!
But really this all comes down to what's the no-compromise solution for an urban electric bike. Have a test drive a Gocycle G4, we think you'll be impressed!
......oh, and the G4 comes with active traction control too!
Answered by Richard Thorpe - Gocycle Designer and Founder