"Re-converting" a Babboe Curve-E

[cargodado]

I have recently bought a 2nd hand Babboe Curve-E 3-wheeler cargo bike (https://www.babboe.co.uk/babboe-curve-e).
The bike itself weights about 60kg, comes with a 36V system and a 250W geared hub motor driving the 26" back wheel.
Together with the passengers (including myself) the whole package would weight ~150kg. The ultimate speed I would ride this thing is around 25km/h.

The motor is fine on the flats and is even ok going up slopes. The problem I have is the PAS that came with this GWA system (http://www.gwaenergy.com/Systems?packageid=13) works on principle of acceleration. So if you accelerate faster (bike speed, not cadence) then the motor will help you more, and vice versa. I live on a road that is ~8% gradient. If I manage to get some acceleration on the flats before it, then the motor will help out most of the way uphill. However if I have to stop midway (traffic lights), then I won't have enough acceleration off the mark to trigger the motor and the ride becomes unbearable.

I tried to look for ways to change the behaviour or to add a throttle, however products from GWA aren't really popular and the system is purposefully locked down.

My questions are: 1) Does anybody have experience with GWA systems? 2) Failing 1), what kind kit would be the best if I want to convert it to a cadence or movement triggered system, perhaps with a stronger motor and battery while I am at it? Please note that no mid-motor could fit onto this bike without cutting some metal up, which I prefer not to do. Thanks in advance!

 

[qwerkus]

I have recently bought a 2nd hand Babboe Curve-E 3-wheeler cargo bike (https://www.babboe.co.uk/babboe-curve-e).
The bike itself weights about 60kg, comes with a 36V system and a 250W geared hub motor driving the 26" back wheel.
Together with the passengers (including myself) the whole package would weight ~150kg. The ultimate speed I would ride this thing is around 25km/h.

The motor is fine on the flats and is even ok going up slopes. The problem I have is the PAS that came with this GWA system (http://www.gwaenergy.com/Systems?packageid=13) works on principle of acceleration. So if you accelerate faster (bike speed, not cadence) then the motor will help you more, and vice versa. I live on a road that is ~8% gradient. If I manage to get some acceleration on the flats before it, then the motor will help out most of the way uphill. However if I have to stop midway (traffic lights), then I won't have enough acceleration off the mark to trigger the motor and the ride becomes unbearable.

I tried to look for ways to change the behaviour or to add a throttle, however products from GWA aren't really popular and the system is purposefully locked down.

My questions are: 1) Does anybody have experience with GWA systems? 2) Failing 1), what kind kit would be the best if I want to convert it to a cadence or movement triggered system, perhaps with a stronger motor and battery while I am at it? Please note that no mid-motor could fit onto this bike without cutting some metal up, which I prefer not to do. Thanks in advance!

Not sure what you are describing. I've seen curve-e's and they work on classic pas basis: you set an assist level, and have to somewhat turn the pedals to start the motor. Some pas have "torque imitation capabilities" where cadence affects assist, but I've never been impressed by it. If you are unhappy with the current setup, you can either go for another controller or a complete different system, which - depending on you abilities - I would do on this cargo: first option means buying a cheap kt controller and set it up according to your wishes, or a more refined lishui one - same principle. Second option: swap the rear hub for an internal geared hub: this will greatly improve startups, since you can shift during stops. Put the battery below the cargo box and then either go for one single side hub motor (simple option) or a differential coupled to an in-runner on the front, where the actual weight will be. That way you can have a powerful motor, regen and two completely separated traction systems (human, electric). Funny: there is a post from a guy that made a diy diff out of angle grinders: https://endless-sphere.com/forums/viewtopic.php?f=3&t=116273