Brompton on Swipe TV.

[Kudoscycles]

Just watched the prototypes of the Brompton e-bike on TV. It appeared similar to the current offering from many on this forum,but they said it had been specially developed by Williams GP engineering.
The girl interviewer made the comment it didn't seem to be working,the MD of Brompton told her she has to press harder on the pedals to get more power....this lead me to believe they have used a torque sensor....I am surprised they have selected a torque sensor......most of my customers want maximum power with minimum rider input and therefore a speed (rotation) sensor is the simpler and preferred choice.
I realise that Brompton has a brand loyalty and is an immaculate fold but £2500 for a small wheeled folding e-bike ???
The timing is unfortunate,if the EU put 50% anti-dumping duty on e-bikes imported into the EU and the U.K. crash out of the EU and Liam Fox does a free trade deal from China then building e-bikes in the UK is going to be very difficult and the market very limited.
KudosDave

 

[Woosh]

most of my customers want maximum power with minimum rider input and therefore a speed (rotation) sensor is the simpler and preferred choice.

I think 2018 will see more e-bikes equipped with torque sensor.

 

[Kudoscycles]

I think 2018 will see more e-bikes equipped with torque sensor.

Why?

 

[Deleted member 4366]

I think torque sensors are diabolical. I haven't yet ridden a bike with one that I'd rather have than my rotation sensor.

It should be easy enough to replace a rotation sensor with a torque one and make no difference to the control system, but nearly all the bikes with torque sensors come up with strange torque multiplication algorithms, which is where it all goes wrong for me.

For me, the perfect system would be similar to the old Storck Raddar, which had a thing like a throttle, which adjusted the power when you pedal. All you need is a switch to switch on when you pedal, then a control to adjust the amount of power you get. By power, I mean current control. The control shouldn't have a spring - like the 5, 7 or 9 levels of PAS you get on some bikes, but infinitely adjustable steps, adjusted by a simple lever or twist-grip. It's when people try to automate that power control that it all goes wrong - for me anyway.

 

[Woosh]

Why?

Bikes with torque sensor don't need brake sensors, throttle, temperature sensor etc. You end up with a bike simpler to build and maintain.
This is the way for Chinese bikes to compete on the mid-range against German bikes.

 

[fatwomble]

Bikes with torque sensor don't need brake sensors, throttle, temperature sensor etc. You end up with a bike simpler to build and maintain.
This is the way for Chinese bikes to compete on the mid-range against German bikes.

Do they really need all those though, I don't run mine with brake sensors and I've never had an issue with the motor stopping when I stop peddling. I don't have a throttle, power kicks in almost straight away. Pretty sure I don't have a temperature sensor, what does that do?

I assume a torque sensor is a cleverer bit of kit than a rotation sensor and therefore more prone to failure.

I'm still a relative newbie to all this, so I'm probably missing some facts and experience, I'm just interested, as I'm not sure a torque sensor bike would work so well for my commute.

 

[Kudoscycles]

Bikes with torque sensor don't need brake sensors, throttle, temperature sensor etc. You end up with a bike simpler to build and maintain.
This is the way for Chinese bikes to compete on the mid-range against German bikes.

But most Brits don't like torque sensors. Reading postings on this forum so often customers don't understand the ditterence between torque and speed sensors.
Also torque sensors are unreliable,even the best have problems.
Torque sensors are sold by dodgy sales guys....customers don't usually want to admit that they want their e-bike to make them lazy so it's easy for a sales guy to sell them a torque sensor bike as a means of increasing their fitness,they get out what they put in.
But in reality customers often (mostly)buy e-bikes to help up hills with tired legs,when they most need assistance the torque sensor limits the power unless you pedal hard.....just like the girl on the TV.
This is shown by customers love affair with speed sensors , they regret the passing of throttles,no rider input required.
But a simple speed sensor gives complete control,it gives the rider access to max power whatever the power the rider inputs,also the speed sensor is more reliable because of its simplicity and in the event of failure more easily replaced.
Kudos will never again produce a torque sensor bike.
KudosDave

 

[Woosh]

Do they really need all those though, I don't run mine with brake sensors and I've never had an issue with the motor stopping when I stop peddling. I don't have a throttle, power kicks in almost straight away. Pretty sure I don't have a temperature sensor, what does that do?

I assume a torque sensor is a cleverer bit of kit than a rotation sensor and therefore more prone to failure.

I'm still a relative newbie to all this, so I'm probably missing some facts and experience, I'm just interested, as I'm not sure a torque sensor bike would work so well for my commute.

many people don't need all those sensors but if you don't put them on your factory made bikes, you may come to regret that decision if later on, it lands you in Court.
There is also a fundamental issue with derestriction on CD bikes. It's a fact of life, no matter how hard you try, some people will derestrict their bikes. With geared hub motors, the output decreases rapidly when the motor approaches its noload speed (around 22-23mph), the motor won't overheat even if the bike is derestricted. With a crank drive motor, you can overload a derestricted motor if you don't fit a torque sensor.

 

[Deleted member 4366]

You need brake sensors on some bikes, but not others because some controllers have more or less instant control from the PAS, others have a noticeable delay. The rule is that the power must stop within a certain time/distance after you stop pedalling unless you have brake sensors. Certainly, the KT controllers meet that requirement.

Brake sensors were also useful when throttles were fitted because a broken throttle can give power all the time, though there was no rule that said you have to fit brake sensors for that reason. There's not many bikes with throttles now, so that eliminates that reason anyway.

 

[Woosh]

You need brake sensors on some bikes, but not others because some controllers have more or less instant control from the PAS, others have a noticeable delay. The rule is that the power must stop within a certain time/distance after you stop pedalling unless you have brake sensors. Certainly, the KT controllers meet that requirement.

you need to factor in customers' clumsiness.
They may continue to pedal or push on the throttle, the chain may come off while they try to brake etc
The torque sensor does not have this sort of issues.