Cadence and torque sensors

[Devilishdeb]

Hi all. I moved from a KTM e Cross P to KTM Bosch driven bike and miss my torque sensor and xperience of the hub drive despite the pitfalls of design. I find up steep hills I have to keep cadence high to get up. These are very steep hills mind does anyone know of any bikes with a combination of cadence and torque ie pressure sensor.
After my less happy experience with the Bosch would be happy to go back to hub drive as well. Thanks.

 

[MarcusT]

Without knowing the type of Bosch you have, but I have the CX with a Purion display and in the Emtb mode, the motor senses the assistance needed and adapts. I usually ride with a cadence of 50-60 and have little problems on steep uphills.
You are right. Wheel drive and pedal drive are 2 different animals, both need getting used to

 

[Nealh]

Wisper torque bikes have both the default is torque sensing with the option of an 'F' mode foe cadence sensing.

 

[sjpt]

I thought all Bosch systems used torque sensor, but maybe that just shows my ignorance.
A (sort of) related question: are there any ebikes that use genuine cadence sensors to adjust power according to cadence, rather than just for on/off?

 

[Electrifying Cycles]

Just to confuse matters the KTM e Cross had a torque sensor but having sold them before it has an incredible kick to it, I think it gave you up to about 400% assistance in the top mode. As someone else mentioned it does depend which motor you are comparing to the hub drive KTM.

 

[vfr400]

The difference in the power and the way the bike gives it is nothing to do with the type of sensor. The KTM is 48v (13S), so it has the potential to make 33% more power and torque than the Bosch, all other things being equal. Hub-motors also give their torque in a more usable way. The torque from the KTM is more or less constant all the way from zero to 15 mph, while as the torque from the Bosch has a distinct band in each gear, so you have to keep your cadence in the right band and be in the right gear to keep the torque high.

 

[mike killay]

Being arthritic, it is always cadence sensor and throttle for me. Torque sensing would be absolutely useless. (I have tried a Bosch)

 

[anotherkiwi]

I thought all Bosch systems used torque sensor, but maybe that just shows my ignorance.
A (sort of) related question: are there any ebikes that use genuine cadence sensors to adjust power according to cadence, rather than just for on/off?

On a kit bike with a KT sine wave controller you adjust power by choosing the assist level. There is another setting for the ramping up of the power - normal, strong and soft start modes are available.

You are thinking of a controller that would give more power the slower you pedal? And as your cadence rises it provides less power because your high cadence indicates you are on easy ground. That would work for me if the controller had a way of knowing which gear ratio you are using at any given time: slow pedaling in low gear = most power on tap and high rpm in higher gear = less assist.

It would be nice if there were Arduino powered controllers on the market with a programming kit.

 

[Devilishdeb]

The difference in the power and the way the bike gives it is nothing to do with the type of sensor. The KTM is 48v (13S), so it has the potential to make 33% more power and torque than the Bosch, all other things being equal. Hub-motors also give their torque in a more usable way. The torque from the KTM is more or less constant all the way from zero to 15 mph, while as the torque from the Bosch has a distinct band in each gear, so you have to keep your cadence in the right band and be in the right gear to keep the torque high.

Yes this totally explains my experience

 

[Devilishdeb]

Being arthritic, it is always cadence sensor and throttle for me. Torque sensing would be absolutely useless. (I have tried a Bosch)

I have Raynauds I can get cramp in the cold with too much cadence

 

[Devilishdeb]

Without knowing the type of Bosch you have, but I have the CX with a Purion display and in the Emtb mode, the motor senses the assistance needed and adapts. I usually ride with a cadence of 50-60 and have little problems on steep uphills.
You are right. Wheel drive and pedal drive are 2 different animals, both need getting used to

Mine is a CX as well. You are right. Ta

 

[Devilishdeb]

Wisper torque bikes have both the default is torque sensing with the option of an 'F' mode foe cadence sensing.

Do they do an mtb or cross bike?

 

[MikeS]

on steep hills with the Bosch active Line Plus I have to do S-shape manouvres to keep the cadence in the right range. Works OK as long as it's not a busy road
Mike

 

[Nealh]

Do they do an mtb or cross bike?

Have a look at their range to see what's available.

 

[lutin]

I've had a cadence/speed sensor now for only about a week (Gtech Escent MTB), but feel like i've got to know how it works a bit.

My experience is that the cadence sensor is basically like having throttle. Pedal movement = throttle on.
As long as the pedals are moving, no matter how little much force you apply, the motor will kick in and attempt to get you up to max speed.
In this respect, the cadence sensor isn't really like riding a bike at all in that the pressure/effort that you exert on the pedals doesn't really matter at all.
This means that for my commute, I do virtually no work at all - I arrive completely sweat-free. This is exactly what I want from an e-bike and I think that for my needs the cadence sensor might actually be better than a torque sensor.

 

[anotherkiwi]

I've had a cadence/speed sensor now for only about a week (Gtech Escent MTB), but feel like i've got to know how it works a bit.

My experience is that the cadence sensor is basically like having throttle. Pedal movement = throttle on.
As long as the pedals are moving, no matter how little much force you apply, the motor will kick in and attempt to get you up to max speed.
In this respect, the cadence sensor isn't really like riding a bike at all in that the pressure/effort that you exert on the pedals doesn't really matter at all.
This means that for my commute, I do virtually no work at all - I arrive completely sweat-free. This is exactly what I want from an e-bike and I think that for my needs the cadence sensor might actually be better than a torque sensor.

You need to find a +17% gradient or two on your way to and from work... On my commute I have no choice, but I don't get too sweaty because of the +500 controller Watts and the very short distance (2.8km) I would sweat a lot more walking for the 28 minutes it would take me on foot.

What you describe can be true on the flat but many of us turn down the assistance level and do a little bit of work there. The "throttle" is more or less powerful depending on assist setting and to reach top speed in level 2 will take quite a bit of effort on your behalf. If you check you will find that you are probably providing more power that you might suspect even at the highest level, "just turning the pedals" is a bit more exercise than driving for example.

Edit: some real world numbers

At the moment I have some sinus issues (heat, pollution...) and yesterday I used 31 Wh to get home compared to 25 Wh when I am fit. That is quite a substantial increase in battery use - about +24%. That is 6 Wh that I usually contribute myself.