Speed Sensor? Torque Sensor?

[The Strong Goat]

Hi Everyone,

Nowadays I think most people already put out the advantages of the Torque Sensor systems compared with Speed Sensor. But as the daily riders, do you think it's really necessary for the ones who are going to purchase an e-bike to spend extra money to have an e-bike equipped with Torque Sensors system? If so, then how much extra cost you think will be fair? Or you think the speed sensor will be sufficient for our everyday use already?

 

[Benjahmin]

I prefer the cadence sensor. It operates simply (effectively as a switch) with no complicated algorhythms to get in the way. Also, when I am towards the end of a ride and getting tired, it still gives me full assistance, whereas a torque sensor would be causing the assist to drop off as my input drops.

 

[The Strong Goat]

I prefer the cadence sensor. It operates simply (effectively as a switch) with no complicated algorhythms to get in the way. Also, when I am towards the end of a ride and getting tired, it still gives me full assistance, whereas a torque sensor would be causing the assist to drop off as my input drops.

Hi Benjahmin,

Many thanks for your reply, I'm actually trying to build an ebike with my friends myself, just wondering whether we should adopt the cadence or torque system. Let's see what others say. Again, many thanks for your comment!

 

[Woosh]

what is needed is a switch between the torque sensor and the throttle.

 

[The Strong Goat]

he torque sensor and the throttl

Thank you Woosh! Once we finish our draft models, I will list all the specs and features here!

 

[Deleted member 4366]

I prefer a cadence sensor because it gives a more controllable power delivery. Use a controller with current control (called "torque simulation" by Chinese).

If you're building a bike, torque sensors don't work very well because the software in the controller isn't as well-developed as the OEM bikes. It's extremely difficult to get the right power algorithms in the software.

 

[The Strong Goat]

I prefer a cadence sensor because it gives a more controllable power delivery. Use a controller with current control (called "torque simulation" by Chinese).

If you're building a bike, torque sensors don't work very well because the software in the controller isn't as well-developed as the OEM bikes. It's extremely difficult to get the right power algorithms in the software.

Hi d8veh,

Thanks for your comment.

I noticed that in some reviewing articles, some pointed out there is some delay in the PAS and makes the riding experience not smooth, like this article:
http://www.uualk.com/why-an-e-bike/torque-sensor-system-vs-speed-sensor/
Have you encountered this problem in your riding experience? If so, do you think that's something annoying during the riding?

 

[Woosh]

don't worry about that. Bikes with Hall sensors start more quickly than bikes without Hall sensors because the latter takes about 1 second to ramp up the power. It has little to do with the difference in activating time between pedal sensor and torque sensor.

 

[The Strong Goat]

don't worry about that. Bikes with Hall sensors start more quickly than bikes without Hall sensors because the latter takes about 1 second to ramp up the power. It has little to do with the difference in activating time between pedal sensor and torque sensor.

Thanks Woosh! I'm learning from you!

 

[Deleted member 4366]

Hi d8veh,

Thanks for your comment.

I noticed that in some reviewing articles, some pointed out there is some delay in the PAS and makes the riding experience not smooth, like this article:
http://www.uualk.com/why-an-e-bike/torque-sensor-system-vs-speed-sensor/
Have you encountered this problem in your riding experience? If so, do you think that's something annoying during the riding?

cadence sensor

1. Motor assistance is set according to the speed. The higher the speed, the higher the assistance. Wrong.
2. It does not save battery energy. Motor continues using battery even in downhill, when the cyclist does not really need assistance. Depends whether you pedal.
3. It maintains an irregular speed during steep slope. The cyclist loses speed even when executes more pressure (torque) on the pedals. Wrong.
4. Shorter distances covered with the same battery capacity. Wrong.
5. It requires bigger batteries to be able to climb steep slopes. Wrong.
6. It requires bigger batteries for the same autonomy than Torque Sensor System. Wrong.
7. Delayed pedal assistance. The motor is activated once cyclist reaches certain speed. Wrong.

Torque sensor

1. Pedal assistance is set according to the effort required. The higher the strength required, the higher the assistance. Turning that around, the more power you want, the harder you need to pedal.
2. Preserves battery consumption. In a steep slope (or whenever the cyclist wants) the motor is deactivated saving energy. No idea what he's talking about there. You can switch off any system.
3. Maintain the speed in steep slopes. Wrong. when your legs get tired, you can't pedal hard enough to get maximum power.
4. Longer distances covered with the same battery capacity. Wrong.
5. It requires smaller batteries to climb steep slopes. Wrong
6. It requires smaller batteries for the same autonomy than speed sensor. Wrong
7. The motor is activated after 0.2 seconds pushing the pedal. Same with modern cadence controllers
8. It allows to adjust assistance between 5 levels. You can have as many levels as you like with a cadence sensor. Oxygen has 6, Bafang has 9. Most have 5 levels.

There are still some cheapo bikes around with old controllers that have delay, but most branded bikes have modern controllers with hardly detectable delay. That's the difference between some £500 Ebay bikes and a £1200 branded one.

 

[Wisper Bikes]

I agree with everything you say Dave except one point.

We have found our bikes with a torque sensor and exactly the same motor and battery will return considerably more range than the same bike with a cadence sensor only.

Another point worth mentioning is our torque sensor bikes are superior when starting on an incline. The power is immediate as the rider pushes on the pedal to start the climb.

I prefer riding a bike fitted with a torque sensor set up than cadence sensor alone. I find it smoother and more natural.

I should say that on our Torque bikes the rider can switch between torque and cadence only settings according to conditions and preferences.

All the best, David

 

[Woosh]

We have found our bikes with a torque sensor and exactly the same motor and battery will return considerably more range than the same bike with a cadence sensor only.

I think the difference can be explained by the fact that your bikes are restricted while d8veh rides derestricted bikes at much higher speed. Riders leg power contributes much less as a percentage in the latter.

 

[Deleted member 4366]

I think the difference can be explained by the fact that your bikes are restricted while d8veh rides derestricted bikes at much higher speed. Riders leg power contributes much less as a percentage in the latter.

Where did you get that from. My electric bike is restricted to 15.5 mph. I ride loads of different bikes because I help out at the local ebike shop doing their repairs.

 

[Deleted member 4366]

We have found our bikes with a torque sensor and exactly the same motor and battery will return considerably more range than the same bike with a cadence sensor only.

Your stating the bleedin obvious, but you have to understand the bleedin obvious reason: You have to pedal harder with your torque sensor bike. Of course it'll go further, but the rider will always be more knackered.

A cadence sensor system can give maximum power with minimum pedal effort if you want, or you can pedal as hard as you want to reduce the amount of power. Your observations would indicate that people with the easier option take the easier option when it comes to pedalling. You don't have so much choice with a torque multiplication system.

It's impossible to get more range out of a motor and battery by using a different sensor. The motor converts battery energy into motive power. It's efficiency is completely independent of the type of sensor.

 

[mike killay]

Your stating the bleedin obvious, but you have to understand the bleedin obvious reason: You have to pedal harder with your torque sensor bike. Of course it'll go further, but the rider will always be more knackered.

A cadence sensor system can give maximum power with minimum pedal effort if you want, or you can pedal as hard as you want to reduce the amount of power. Your observations would indicate that people with the easier option take the easier option when it comes to pedalling. You don't have so much choice with a torque multiplication system.

It's impossible to get more range out of a motor and battery by using a different sensor. The motor converts battery energy into motive power. It's efficiency is completely independent of the type of sensor.

You can even 'under pedal' (i.e. not applying any torque at all) a cadence system and the motor will give full power.
Personally, I cannot understand this wish to have an ebike that rides and looks like an ordinary bike.

 

[Wisper Bikes]

I agree re the reasons we get so much more range from torque sensor bikes.

I prefer the smoother delivery of power and enjoy the sensation of having powerful legs rather than the on or off feel of cadence sensor. Just my preference.

 

[mike killay]

I agree re the reasons we get so much more range from torque sensor bikes.

I prefer the smoother delivery of power and enjoy the sensation of having powerful legs rather than the on or off feel of cadence sensor. Just my preference.

Each to his own.
I confess that I am getting on in years and cannot manage a non throttle bike very well, so what is in effect a low powered moped that will get me home despite arthritis is my preference.

 

[Wisper Bikes]

Each to his own.
I confess that I am getting on in years and cannot manage a non throttle bike very well, so what is in effect a low powered moped that will get me home despite arthritis is my preference.

I know the feeling! At 63, with one new hip and one that needs replacing!

I ride using the torque sensor settings on my 705Torque and when I need more help I simply twist the throttle which overrides the torque settings. The best of all worlds.

All the best, David

 

[Deleted member 4366]

I'm with Mike on this one. I use my road bike more than my electric bike so I'm quite capable of pedalling, but I don't get why people want an electric bike to be like an unassisted one. It's like they're trying to kid themselves that they're not actually using an electric bike. You can pedal as hard as you want with either system, but you on a cadence system, you control the amount of assistance you want with your brain, not how hard you pedal.

Though I wouldn't use a throttle for normal riding, I find one so useful that I wouldn't want a bike without one.

 

[The Strong Goat]

Thanks all you guy's input regarding this topic. One thing I'm sure now is that everyone has his own preference and there is no a definitive answer to this question and no need to have one as well. Also, you guys help me understand further why people even need an ebike, some use it for fun and some use it to make their lives easier. I have to confess this is a place where I can learn a lot after reading your guy's input and posts. Afer all this, I think in the path of making my own ebikes, I think I can not just cover all people's need. I think I need to focus on one direction and make it good instead of diversifying the models with no features at all in the end!