Questions on Brompton ebike sensor

sjpt

Esteemed Pedelecer
Jun 8, 2018
3,680
2,675
Winchester
I have a few questions on the Brompton ebike and its sensor/control mechanism.

A friend bought one a week or so ago; his wife's happy but he isn't so happy. (They had thought of buying a pair).
His main issue is he says it takes two pedal turns before the assist really kicks in; that seems high even for cadence sensor.
Description talks about 'combined torque and cadence sensor'
Looking at reviews (below) some talk about delay in initial power, and others how great it is the power kicks in at once.

Another thing that put him off was the test ride area was just a small yard,
and the shop put it onto full power for his first test which was a bit alarming.
Again doesn't sound like a quality torque sensor.

So the questions:
Have there been different versions of the Brompton with different sensors?
What sensor does it really have?
What is people's experience with the control system?

~~~
What this makes for is a spritely kick off the line. Putting down the pressure at a set of traffic lights, you are comfortably the quickest thing off the mark, propelling clear of other traffic in an instant.

There’s also a slight delay before it kicks in after you’re already pedaling,

The following also seems a bit extreme; being impatient or forgetful at startup meaning a trip to the dealer?
When switching on your bike, your bike will perform an autocalibration which will reset the components to provide a more consistent ride experience. It is very important that you allow, around 30 seconds for the bike to start up before riding. Do not move the bike or peddles during this first 30 seconds. If you do move the bike during this period, the 'brain' of the bike will become confused and the ride feel will deteriorate. This will also mean that you will need to make a trip to your Brompton Dealer to rectify the problem.
 
D

Deleted member 33385

Guest
Do Bromptons get sent out of different factories or dealers, with what look like arbitrary (and different) firmware settings, like the Bafangs?


Another thing that put him off was the test ride area was just a small yard,
and the shop put it onto full power for his first test which was a bit alarming.

On a Bafang BSS01b for instance, that's easily recitified by setting the PAS start current to "10" (was originally "20"). Until I did that, I almost zoomed off the road, while attempting slow U-turns.

It'd be great if more manufacturers allowed extensive tweakage of firmware - without the ability to change top speed - to keep such tweakaging legal.


It is very important that you allow, around 30 seconds for the bike to start up before riding.

Hangovers can be terrible... Or could it be subsystems reporting their status; data signals similar to CANBUS? We need a Brompton expert...
 
Last edited:

Woosh

Trade Member
May 19, 2012
19,529
16,466
Southend on Sea
wooshbikes.co.uk
His main issue is he says it takes two pedal turns before the assist really kicks in; that seems high even for cadence sensor.
that can't be right.
 

BigG

Pedelecer
Oct 5, 2016
122
53
72
Co Durham
Hi.... If you start with the LEFT pedal, the power should come in after 1/4 to 1/2 a rotation of the pedals.
I have had two electric Bromptons and that's how they worked, as did the demo bike I tried.
Good luck