Level 2 - Torque Sensor Question

[salaryman]

Hi There
I recently purchased a Level 2. It's a very different ride from my previous ebike (Rad City Plus 5) which seemed to always have the motor going
and made peddling easier, I like the feel of the L2 as it seems closer to actual riding and I get a very good workout from it, plus battery lasts longer.
It has five levels of pedal assist, but I never use it past P1 as I can't peddle much faster than 13 miles. When I move up to P2 or P3 I am
assuming that I need to peddle harder and longer for it to go faster. Is this a correct assumption on my part or is there
something wrong with my Level 2? Hope this makes sense and appreciate any feedback/help.
Thank you in advance

 

[Jeremy McCreary]

When I move up to P2 or P3 I am
assuming that I need to peddle harder and longer for it to go faster. Is this a correct assumption on my part or is there something wrong with my Level 2?

Not correct. I've put in ~30 miles on a friend's Level.2 and ~3,000 miles on a very similar 500W torque-sensing hub-drive of my own. In both cases, the harder you push on the pedals, the more assist you get from the motor. This is true in ALL assist levels. Higher assist levels just provide more motor power for a given pedal force. Simple as that.

Try this on a flat road: Pedal for a while in P1 at a steady comfortable ground speed till you have a good feel for the pedaling effort and cadence (pedaling speed) involved.

Then upshift 1 gear AND increase assist to P2 at the same time, keeping the same effort and roughly the same cadence as before. You should be going significantly faster now with similar effort.

Finally, repeat WITHOUT upping assist to feel the difference.

Running the whole experiment again with P2 and P3 and so on should produce similar results. If you're experiencing something substantially different, something's probably wrong.

 

[salaryman]

Hi Jeremy, Thank you very much. I tried what you suggested and could the results that you mentioned on P2 and P3.
Definitely felt the difference. Is it correct to state then that unlike my old Rad, where going up assist levels didnt require me
to pedal any harder, on a bike with a torque sensor like the Level 2, I will get more power to the engine but I will also need
to pedal harder to sustain that speed? That seemed to be my experience at P2, P3, and P4 levels this afternoon.
Thank you

 

[Jeremy McCreary]

Not sure I follow, but I think I see where some of your perceptions are coming from.

I believe your Rad has simple cadence-sensing assist. Under that system, motor power is all-or-nothing. When the bike detects any pedal motion at all, you get full motor power — even if you're turning the pedals with no real effort. (That's called ghost-pedaling.) Otherwise, the motor's off. Assist level typically controls only the ground speed at which assist cuts out.

As I explained earlier, torque-sensing assist is nothing like that. You have to pedal hard or use the throttle to get full motor power, and ghost-pedaling gets you little or none.

With the torque-sensing Level.2, you'll have to adjust your expectations and motor use accordingly. Pedaling at highest assist or throttling around without pedaling are always options, but battery range will suffer accordingly.

 

[salaryman]

Thank you, Jeremy-this makes perfect sense and I get it now! Yes, it was ghost peddling that I was referring to
Roger

 

[PedalUma]

The Level 2 has both torque and cadence sensors. The very best bikes 'like' a high cadence. Like a sports car you down shift to accelerate then rev it up before upshifting. Try the experiment of pedaling at high speed in a low gear at full power. The experience will be very different than a Rad.

 

[salaryman]

Hi There PedalUma - Thank you for the response. I checked and my L2 only has the Torque sensor and a throttle but not a cadence sensor.
Roger

 

[PedalUma]

Hi There PedalUma - Thank you for the response. I checked and my L2 only has the Torque sensor and a throttle but not a cadence sensor.
Roger

@salaryman, They do not talk about it because that would confuse average consumers. Yes, it has both. I sell and work on these bikes everyday. Did you try pedaling at high speed in a low gear with almost no pedal pressure? I will do it today. Oh, the sale on these bikes today is amazing.

 

[salaryman]

Wow-did not know that!

 

[Jeremy McCreary]

@salaryman, They do not talk about it because that would confuse average consumers. Yes, it has both. I sell and work on these bikes everyday. Did you try pedaling at high speed in a low gear with almost no pedal pressure? I will do it today. Oh, the sale on these bikes today is amazing.

So the Level.2 has a true cadence sensor measuring cadence in RPM, not just a yes-no crank rotation detector? (Has to have at least the latter for safety reasons.)

Will have to try this test on my neighbor's Level.2.

 

[PedalUma]

@salaryman, I took one up a five story parking garage this morning to do the test. For a test you will want to run at extremes. A) At power level 5 I ran it in first gear at a cadence of 100 with very low pedal pressure, but some. The Level 2 ran fast and smooth. That was the cadence sensor check. It is set to deliver more power at higher cadences. I also reached the cadence cut out and the torque cut out by spinning at over 100 without enough pedal pressure. B) I ran the Level 2 in high gear while standing in the pedals BMX style. I only applied full pedal pressure from 12 O-clock to full down 6 O-clock and waited two clicks before doing it again with the other pedal to test the torque sensor response. The motor kick-in did not happen until I reached 5:35 O-clock. It was laggy and displayed surge and lurch. Conclusion: This bike responds better to a high cadence than to pedal pressure, AKA torque. Yes, I was pushing unnatural limits for the test. Otherwise it is smooth and feels natural in most circumstances. Bottom Line: To accelerate, downshift and up cadence then apply lots of pedal pressure before upshifting, shift when backing off like a clutch, and do the same again for each upshift. You will fly.

 

[rcdanner]

The Level 2 has both torque and cadence sensors. The very best bikes 'like' a high cadence. Like a sports car you down shift to accelerate then rev it up before upshifting. Try the experiment of pedaling at high speed in a low gear at full power. The experience will be very different than a Rad.

I'm curious to know where the two sensors are located. A photo identifying them would be helpful. I do remember Aventon bikes used to use a Speed Cadence sensor rather than Power Cadence sensor of other brands like Ride1Up. But now their bikes seems to use torque sensor technology.

 

[PedalUma]

I'm curious to know where the two sensors are located. A photo identifying them would be helpful. I do remember Aventon bikes used to use a Speed Cadence sensor rather than Power Cadence sensor of other brands like Ride1Up. But now their bikes seems to use torque sensor technology.

Some R1Up bikes such as the Portola use watts instead of strain. It is a torque simulator that is Okay for most. I am not fully sure but think that it is all in the bottom bracket. Bafang lunched it in 2022. And it has been refined since. An Aventon Level 2 failed today reverting to a purely cadence bike of yore. Any pedal movement at all made it go full speed up to its rider set power level. It could be ghost pedaled just like a RAD. Most R1Up bikes have a torque/cadence combo in their BB. R1Up Revvs have shot pedals and poor riding positions, so they are really just throttle bikes with afterthought pedals. The new Aventon Abound SR is very nice but limited to 20.

 

[Jeremy McCreary]

I do remember Aventon bikes used to use a Speed Cadence sensor rather than Power Cadence sensor of other brands like Ride1Up. But now their bikes seems to use torque sensor technology.

I'm familiar the the so-called "cadence sensors" used in most inexpensive ebikes. They're really just yes-no crank rotation detectors and don't measure crank RPM at all. Also familiar with torque sensors.

But the terms "Speed Cadence sensor" and "Power Cadence sensor" are new to me. Could you explain? Thanks!

 

[rcdanner]

I'm familiar the the so-called "cadence sensors" used in most inexpensive ebikes. They're really just yes-no crank rotation detectors and don't measure crank RPM at all. Also familiar with torque sensors.

But the terms "Speed Cadence sensor" and "Power Cadence sensor" are new to me. Could you explain? Thanks!

Speed cadence sensors power the bike to a 'set speed' for each PAS level. When that speed is reached power is off while pedalling. Up hills even when that speed can't be attained power is still being provided. I have found at lower PAS levels maximum power is somewhat tapered. On my Aventon Pace 500 Ver 1, Level 1 speed is approximately 8mph. Level 2 is about 11mph. And so on.

Power cadence sensors apply set power for each PAS level. That power is applied no matter what speed (up to usual 28mph limit) while pedalling. Up hills that set power is applied no matter the speed. I have found that power output varies only slightly for each PAS level. On my Ride1Up LMTD Ver 1, In level 1 power output is approximately 120 watts. Level 2 power is 250 watts. And so on. R1U allows power levels to be altered in the menu.

 

[Jeremy McCreary]

Speed cadence sensors power the bike to a 'set speed' for each PAS level. When that speed is reached power is off while pedalling. Up hills even when that speed can't be attained power is still being provided. I have found at lower PAS levels maximum power is somewhat tapered.

Power cadence sensors apply set power for each PAS level. That power is applied no matter what speed (up to usual 28mph limit) while pedalling. Up hills that set power is applied no matter the speed. I have found that power output varies only slightly for each PAS level.

Sounds like these terms refer to assist strategies rather than the sensors themselves. Where do they come from?

Are both strategies based on a typical "cadence sensor" that simply detects crank rotation without actually measuring crank rpm?

 

[harryS]

Sounds like these terms refer to assist strategies rather than the sensors themselves. Where do they come from?

Are both strategies based on a typical "cadence sensor" that simply detects crank rotation without actually measuring crank rpm?

Most hub motor cadence controllers don't measure pedal speed. They use pedal motion as an on/off switch for assist, Then they use either speed control or current control as described above, My KT controllers have a choice or selecting one or the other. When Ahicks was around, he talked abiut trying speed control on his KT controller and how poor it worked. I never bothered experimenting, Always ran current control.

Meanwhile my $250 TSDZ2 middrive kit use both a cadence sensor and a torque sensor. When you reach cruising speed on a T/S bike, the pedal pressure falls off. Troque sensor signal falls off. What should the motor do? Knowing how fast the pedals are spinning, the motor algorithm decides whether to maintain power, start slowing down, or cut power. If my cheapo unit can do that, the $2000 mid drives obviously do that too,

 

[Jeremy McCreary]

Most hub motor cadence controllers don't measure pedal speed. They use pedal motion as an on/off switch for assist, Then they use either speed control or current control as described above, My KT controllers have a choice or selecting one or the other. When Ahicks was around, he talked abiut trying speed control on his KT controller and how poor it worked. I never bothered experimenting, Always ran current control.

Meanwhile my $250 TSDZ2 middrive kit use both a cadence sensor and a torque sensor. When you reach cruising speed on a T/S bike, the pedal pressure falls off. Troque sensor signal falls off. What should the motor do? Knowing how fast the pedals are spinning, the motor algorithm decides whether to maintain power, start slowing down, or cut power. If my cheapo unit can do that, the $2000 mid drives obviously do that too,

Interesting points. My hub-drive's rear dropout torque sensor includes a cassette rotation detector, the latter only for safety reasons. The bike has no way to measure crank RPM, but it still manages to deliver very natual-feeling assist. Definitely one of the bike's strong points.

In contrast, my Specialized mid-drive (Vado SL) has much more sophisticated rider power-sensing assist. The mechanical motor power delivery is even more natural-feeling, but it's by no means a night-and-day improvement.