My bike seems to deliver power inconsistently. I've tried to experiment by cycling, on my commute, steadily and consistently. Sometimes the power is delivered in a steady useful stream. Sometimes the power delivery comes and goes in sort of waves.
My (black) Brompton Electric also behaves this way. I haven’t taken it or my wife’s white one for their first service so far. Our factory visit last year led me to believe the then imminent firmware update that will be installed during a service will address inconsistent power delivery.
At other times the motor seems to offer resistance to pedalling.
I haven’t felt resistance on either bike. I often sense a lack of assistance but no actual drag. The motor stops assisting at 25KPH but I’m guessing that this is not what you are describing.
If you take the battery off, turn the bike upside down and spin the front wheel what do you see and hear? Our white bike made an unexplained ticking sound during this test and that factory swapped the motor when I demonstrated it. After this, the white bikes now goes faster than the black one and consumes more battery power (still original firmware on both) when we are riding together.
Is this normal for e-bikes? What should I expect from this type of e-bike motor set up?
Our 2014 BH Neo Electric bikes deliver consistent assitance to the rear hub motor proportional to our effort as soon as the pedal is depressed. Power is smooth. They feel quite different to the Bromptons where the pedal needs to rotate through a certain number of degrees before any assistance to the front hub motor is provided.
The Neo senses rider effort with a torque sensor attached to the rear mech but the Brompton has a cadence sensor in the bottom bracket that, I am told, is sensitive to the movement of the left pedal. This makes a difference to how the controller senses what the rider is doing and how much assistance to add. Brompton advise that higher cadence (faster pedal rotation) will deliver more assitance. I have tried this but can’t say it made a noticeable difference.
The Neo continues to provide assitance for a short (<1 second) but significant period after pedalling stops. Assistance stops the moment the brakes are applied as both levers have detection switches. The Brompton has no brake sensors (too many cables for “the fold”?) so I believe it cuts the power as soon as pedalling stops, presumably for safety reasons.
All told, we much prefer the assistance provided by our old electric bikes. And they are more comfortable over rough surfaces. But they are heavy, don’t fold up and disappear into the car boot, into the motorhome or next to the train seat.
I am hoping the firmware and/or motor replacement will provide a more consistent and useful power delivery once I get round to taking them into the city for a service.
Brompton Electric is a city bike, designed to be manoeuvred around the built environment with all of its hazards. I suspect that the cadence sensor and lack of brake detection coupled with Brompton’s safety consciousness about only applying power when the bike is certain the rider intends to go forward will always make this a machine that delivers assitance sensitively.
To be balanced, one of the BH “powerful and comfortable” Neo bikes suffered from a dirty torque sensor in France last June and twice launched itself without a rider. Luckily this was on a campsite and not in front of a lorry or double decker bus but it did shock the rider and left her very nervous about using it until we worked out the cause. A tiny touch of the peddle was all it took. The other Neo has since done something similar as I was pushing it while turning, which the torque sensor interpreted as “rider on board and launch”! My point being that the Brompton doesn’t start to assist until it is sure the rider intends to proceed and seems to cut its assistance the instant it believes the rider could be about to stop and these safety measures might sometimes feels like reluctance. Here’s hoping the newer firmware is just as safe but removes the reluctance.
Has anyone got the latest firmware and/or motor and did it deliver a more satisfying ride experience?