Does a torque sensor aid a strong rider more than a weak rider?

[Hilary M]

Hello, I am new to the forum and I am researching e-bikes with a view to switching from my Specialized Expedition which I have had for ages and love to bits, but since retiring and moving to a coastal area with hills, I see the need to get an e-bike if I want to keep riding regularly. I have done a lot of research to understand the different types of e-bikes, how they work etc, and I think I have found answers to all my questions from extensive reading, watching videos, etc, but I still have one unanswered question re: torque sensors. From my reading a torque sensor bike responds to the amount of pressure applied to the pedals. So, the harder you push, the more power you get –up to the max for that particular power assist setting. If all that is correct, then my right brain tells me that if two people, one young, fit, strong and male, the other, the opposite in every respect (namely, me) ride the same bike with the same gear/power settings up the same hill, then the other rider is going to get more help from the bike because they can push on those pedals harder than I can. Which doesn’t seem fair, because I need the help more! I quite understand that in the real world there are many factors to consider, such as hub vs mid-drive motors, size of motor, weight of rider etc etc. I am specifically interested in a purely theoretical answer to the question – does the inherent nature of a torque sensor assist a strong rider more than a weaker one? I just like to understand how things work!!

 

[Captain Slow]

That's an interesting question. I will admit I don't know for certain but I don't think your hypothesis is entirely correct.

Generally most bikes will have different power level settings. If you set to the highest power mode then I think as long as you can provide enough torque at the pedals (I don't think it's a lot) then you will get maximum power from the motor. So I don't think a stronger rider than you is going to get more assistance from the motor.

But let's see what others think.

 

[AHicks]

Sounds good to me too, but I have to admit I'm completely spoiled by the cadence sensor w/PAS levels and have no torque sensor experience.

In theory, you could assign different levels of assist to the torque sensor to level the playing field. Very similar to the cadence/PAS level system, some are going to want/need more assist than others when using a torque sensor.

The part of the torque sensor plan I don't care for is the lack of a throttle on a lot of them, which I use to get me moving for the most part. Makes it easier to get the bike moving from a stop while getting your balance (sometimes a challenge for us old farts). It's just about the first 3-4' of travel.

 

[jbizzybiker]

Interesting question. As explained to me, a newbie to ebikes with limited overall biking experience, the torque sensor kicks in by defining how hard you NEED to work, indicating to me the weaker person works harder and the torque sensor picks up info to aid/assist.

Again, as a newbie, I recently found myself poorly communicating with a very experienced biker/shop owner as I was speaking “torque” and he is fully fluent in “cadence/rpms“.

 

[6zfshdb]

From the many ebikes I tested before buying, I found the torque sensor reacts differently with every brand. My advice is to test ride as many as you can.

The torque sensor on the bike I bought applies more or less power depending on the PAS level set. More power is applied for a given pedal effort in PAS 2 than in PAS 1. In this case, you would simply set the appropriate PAS level to match the pedal effort you are comfortable with. The PAS level also determines the speed at which the power assist cuts out. Not all bikes operate the same way however. That's why test rides are so important!

My wife and I have the same bikes. She is more comfortable using PAS 3 where as I use PAS 1 or 2. Our bikes are class 2 which means they have a throttle. We find it helps to apply a little throttle when first starting out and occasionally to match each others speed. Check your local laws however to make sure Class 2 bikes are legal where you plan to ride.

 

[Stefan Mikes]

My understanding is the following:

With the mid-drive motor e-bike (which is equipped with a torque sensor), yes, the stronger rider will get more motor support until the pedal assistance power hits its ceiling. A good proof of that is this: Stronger riders of this type of e-bikes often ride almost solely in the Eco mode (the least support) and even switch the pedalling assistance off for flat route segments despite of the fact the e-bike is heavy and often causes some pedalling resistance from the motor. Weaker riders always ride with the PAS on and prefer higher assistance levels.

There is an interesting point here. Mid-drive motors from big brands (Bosch, Brose/Specialized, Yamaha/Giant, Shimano) offer improbable boost or high torque despite of the 250 W nominal power that helps the weaker riders at the cost of battery charge (or -- in other words -- at cost of reduced range). For example, the Specialized 1.3 motor can pump perhaps 520 W in peak.

Example

Both Specialized and Giant talk about "rider's leg power multipier". Let us discuss a strong rider A (200 W leg power output) and a weak rider B (100 W of power). Specialized Turbo e-bikes with the 1.3 motor offer support from zero to 400% of the rider's leg power. In case of the rider A, only 100% PAS adds additional 200W from the motor; 125% would reach the maximum continuous motor power of 250 W. To avoid that, a Specialized e-bike rider may reduce the assistance to, for example, 50% of PAS. Additionally, the rider can apply Peak Power ceiling to conserve the battery charge.

The rider B needs to apply the 200%, or 2x PAS to get the same 200 W assistance. However, if the rider applies 4x torque multiplier, he or she will get 400 W power burst from the motor. It is more than enough to negotiate a hill, even for a weak rider.

Giant operate with the same concept, only assistance multiplier for the SyncDrive Pro motor is limited to 3.6x or 360%. SyncDrive Pro appears to provide even stronger burst of power than the Specialized 1.3 motor, preferring stronger riders (but I cannot find the hard data for it at the moment).

The summary: Even a weak rider of a big brand mid-drive motor e-bike can use the motor to its full capacity if the highest PAS level is used (and the derailleur is applied properly). This happens at the cost of the battery charge.

Specialized has recently come with the SL (Super Lightweight) line of their e-bikes: Creo SL, Levo SL, Vado SL. These e-bikes are equipped with low-power lower torque motors, are lightweight and are equipped with a small battery. Yet the reported range is phenomenal. Why? Because these bikes are targeted at strong riders who would only ask for PAS for climbing and against headwind.

For example, the Specialized Turbo Vado SL offers 2x rider's torque multiplier while the "full" Vado gives up to 4x PAS.

Hub motors

Very few geared hub-drive motor e-bikes offer torque sensor. The PAS is constant and depends on the PAS level and the motor power. The rider has to make up the lacking power of the motor, especially on the climbs.

 

[vincent]

Hilary I would say in general you are right but as all ebikes are not built the same and to the same specs this can still vary

A lowered powered euro mid drive even if it gives 80-90 torque nm is going to be a harder ride for a weaker rider than most 1000 -1500 watt bike whether mid or hub

If you live in a lot of hills a mid drive may be better but you might be best with one of the higher powered mid drives like a flx with bafang m600 or bafang ultra motor

Pushkar from Wattwagon is building a light m600 motor bike now

The advice to ride as many as possible is good But we also know that is not possible for everyone

And unless you can ride the bike a few hours in your terrain it is hard to tell sometimes

I started a thread called mid drives are not for everyone, think it is in the general forum and would probably be helpful

 

[fooferdoggie]

I don't agree I often climb 14 to 16 degree slopes (up to 25 %) on my Bosch speed without a problem. or 1500 feet of climbing in a hour or so. I am not even in great shape. it is a little work on the 16 but it is not really hard. more then that and I have to work hard but those slopes are pretty rare.

 

[Stefan Mikes]

I rode up an 18% slope (and 2660 ft elevation gain on the trip) on my Trance E+ 2 Pro recently, 250 W nominal Yamaha/Giant mid-drive motor. No big brand offers their e-MTB with a hub motor. The same applies to smaller respected manufacturers of e-MTBs.

 

[vincent]

I am sure I could ride up that too on my Yamaha

Also Sure I can do it easier with my bafang ultra bike or a 1500 watt hub drive

Remember when Ravi rode across half the country on a Stromer, it can be done on a hub drive also

But as usual you missed the point of this persons post and made it about you and your riding

It is unfortunate for new posters on this forum that ask anything about mid drive vs hub drive vs torque vs cadence that 8-10 people with euro mid drives dominate the replies and denigrate anyone who does not agree with them

At this point feel there have to be other forums that are not as biased and have to hope those people find those forums

This forum is SMALL

 

[jaizon]

I am sure I could ride up that too on my Yamaha

Also Sure I can do it easier with my bafang ultra bike or a 1500 watt hub drive

Remember when Ravi rode across half the country on a Stromer, it can be done on a hub drive also

But as usual you missed the point of this persons post and made it about you and your riding

It is unfortunate for new posters on this forum that ask anything about mid drive vs hub drive vs torque vs cadence that 8-10 people with euro mid drives dominate the replies and denigrate anyone who does not agree with them

At this point feel there have to be other forums that are not as biased and have to hope those people find those forums

This forum is SMALL

So, where would you say something like an Evelo Aurora Limited would fit into these calculations? Thanks.

 

[rich c]

On my Haibikes with Bosch, I hit the max current from the torque sensor without even getting out of the saddle. It's not hard to hit that max, and with gearing even a new rider could hit the max for quite some distance. I see no credence in your theory. As mentioned, ride before buying. You be the judge before taking the agreement of people that have never ridden a torque sensor eBike.

 

[vincent]

Are you seriously implying I have do not own torque sensor ebikes? Lol lol

I have owned two yamaha powered haibikes
Easy motion torque sensor hub bikes
Bafang ultra torque sensor bike
M600 torque sensor bike

And numerous hub drives with cadence

 

[vincent]

Jaizon, looks like a very cool bike

I did not see which mid drive that is on their site, going to see if court reviewed it And said which one right now

 

[jaizon]

It is mentioned. I do not remember it at the moment. Sorry. I will go look as well.

 

[vincent]

Looks like the last one of those reviewed was in 2018 with the bbs02 and that did not have torque sensor

So not sure exactly which mid drive motor this is but looks powerful and I am sure it would be a great bike
Evelo has great warranty

 

[jaizon]

Looks like the last one of those reviewed was in 2018 with the bbs02 and that did not have torque sensor

So not sure exactly which mid drive motor this is but looks powerful and I am sure it would be a great bike
Evelo has great warranty

It is not a Bafang. Something else, 750 with torque sensing.

 

[jaizon]

Dapu - 750w/1,000 max!

 

[vincent]

I dont know much about Dapu motors but those torque numbers Etc look nice

maybe some others that have the Dapu mid drive on their evelo will chime in that sub forum

would be interesting to hear how they like them

from what i have read about evelo in the past most people are really happy with their bikes
think they have a 30 day return or something also?? Not sure how involved that process is or What the cost is

 

[jaizon]

The Dapu motor is custom made for Evelo and has overcome some of the shortcomings of other Dapu motors. 21 day return. I hope some others chime in as well. I ride a cadence sensor trike now. My only experience.