Cadence sensor riding experience

ned37

New Member
I wouldn't expect her to use throttle that much since we're trying to get a good workout
that's actually backwards. pedaling on the level with even pas1 requires next to no effort. using the throttle when you start to feel you need it gives you a better workout.
 

Lightning P38

Active Member
I'm in California. I wouldn't expect her to use throttle that much since we're trying to get a good workout, so PAS should be the primary usage. But it is still nice to have a throttle available whenever needed.
On mine, assist level 1 tops out at about 5 mph, level 2 tops out at 10 mph, level 3 at 15 mph, level 4 at 20 mph, level 5 at 28 mph. Whatever level I am in will limit the throttle to that top speed. Since I usually ride in level 2, my throttle will take me up to 10 mph from a dead stop, without pedaling.

The throttle only works when you are not pedaling......if you are pedaling the pas is already working the motor.

From a dead stop, I always start out in the low gear of the rear derailer, and work my way up the gears...and I don’t have to touch the pas setting as I use level 2 as my default setting. I rarely use level 1, as it is too slow.
I mostly use level 2 and 3 depending on the terrain and who I am riding with.

I very rarely use the throttle.
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
that's actually backwards. pedaling on the level with even pas1 requires next to no effort. using the throttle when you start to feel you need it gives you a better workout.
That's the case with some PAS systems on some bikes, but not all of them. Where it's an issue, some meat head that wrote the software has too much voltage going to the motor at minimum. Others, with bikes that have less voltage going to the motor under the same conditions, don't have that problem.
 

Lightning P38

Active Member
That's the case with some PAS systems on some bikes, but not all of them. Where it's an issue, some meat head that wrote the software has too much voltage going to the motor at minimum. Others, with bikes that have less voltage going to the motor under the same conditions, don't have that problem.
I was unimpressed with the response using the throttle when I first got my ekit installed, as I get a stronger kick when I pedal and the pas kicks in more torque than using the throttle. I suppose it is programmed that way. I don‘t think it is just my imagination?
 

Lightning P38

Active Member
That's the case with some PAS systems on some bikes, but not all of them. Where it's an issue, some meat head that wrote the software has too much voltage going to the motor at minimum. Others, with bikes that have less voltage going to the motor under the same conditions, don't have that problem.

Also, when using the throttle only, it doesn’t seem to make any difference if I give it full throttle or just a touch of throttle, the response seems to be the same?? Or at the least, very little difference.
My kit came with both a thumb and a grip throttle. I installed the thumb throttle as it was easier to install, as I didn’t have to remove the handlebar grip to install it.
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
I was unimpressed with the response using the throttle when I first got my ekit installed, as I get a stronger kick when I pedal and the pas kicks in more torque than using the throttle. I suppose it is programmed that way. I don‘t think it is just my imagination?
If you told us what kit/controller you have, I've forgotten. What is it?
 

Lightning P38

Active Member
If you told us what kit/controller you have, I've forgotten. What is it?
It is an e-bikekit. It is a 36volt kit. The controller is not labelled, except for the e-bikekit name on it.
They no longer sell the 36 volt kit, as they sell the 48 volt version now, with a $200 price increase. I have the 500 watt geared hub on the rear wheel. It meets my needs very well.
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Sorry I can't be more help. Not familiar with Ebikekit hardware.
 

pkchari

New Member
Region
USA
City
Redmond, WA
That's the case with some PAS systems on some bikes, but not all of them. Where it's an issue, some meat head that wrote the software has too much voltage going to the motor at minimum. Others, with bikes that have less voltage going to the motor under the same conditions, don't have that problem.
I feel there might be some extent to which this could be motor and/or gearing related in addition to engineering/design goals. In this case, "gearing" refers to the planetary gears in the motor housing for a geared motor rather than the gears on the cassette/freewheel. Direct-drive motors have only as much torque as the actual electric drive system itself can provide, and different motor designs might have limits on starting torque, which if it is too small, will not even move the wheels. As a result, they will try to apply an initial burst at higher voltage to get things moving only to scale it back once there is some actual movement. This is akin to how fans (which also have very low torque direct-drive motors) will start up with high torque first; it's also why fans have "high" as the very first setting after "off." For geared motors, you don't necessarily have that same torque issue because the planetary gearset will give you some torque multiplication. However, the core motor RPM has to be higher since there's a step-down gearing in effect. That multiplier not only affects getting up to speed from a stop, but also accelerating since a, say, 2:1 gearing ratio means double the absolute core RPM difference for the same absolute speed difference vs. a direct-drive setup. Since it would normally take longer to get up to that higher RPM for a given power input, that could give a feel of a laggy response, which is potentially undesirable. To counteract this, firmware programmers will probably just boost the voltage during acceleration so that the "revving" up and down can happen more quickly and response feels immediate.

Also worth noting is that bikes, AFAIK, don't really have a true weight sensor, so they will provide whatever starting torque/power output they need for the upper limit spec'ed mass of bike + rider. So if a bike is spec'ed to carry up to a 275 lb rider (which in engineering-land really means that 325 lbs is safe, but not recommended), and a 130 lb rider gets on that bike, that motor controller is going to accelerate at a level fit for roughly double the overall weight. Now in principle, a torque sensor can negate this since a lighter-weight rider is likely to also put less strain on the crank than a heavier one, so you get a mock weight-based scaling effect that way.

A pain point of cadence sensors is that the need for immediate response is quite possibly what becomes a limiting factor in how smooth they will be. A person's instantaneous pedaling cadence is naturally uneven through the cycle, but in order to respond quickly, they will measure your cadence as soon as possible and just roll with it. If you wait for a full cycle at least, you can use the "average" cadence to get something more accurate, but again, you get a delayed onset of power that people might find too laggy. You could also scale the estimated cadence according to the specific angle since the amount of force people can apply through the pedal stroke is pretty predictable, but you'd need some sort of crank position sensor. Whatever the case, different companies will prioritize the quick response vs. smoothness balance differently and different models of motors will have different gearing ratios and so on.
 

GenXrider

Active Member
Uhhh... I recommend you read this thread:
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
I feel there might be some extent to which this could be motor and/or gearing related in addition to engineering/design goals. In this case, "gearing" refers to the planetary gears in the motor housing for a geared motor rather than the gears on the cassette/freewheel. Direct-drive motors have only as much torque as the actual electric drive system itself can provide, and different motor designs might have limits on starting torque, which if it is too small, will not even move the wheels. As a result, they will try to apply an initial burst at higher voltage to get things moving only to scale it back once there is some actual movement. This is akin to how fans (which also have very low torque direct-drive motors) will start up with high torque first; it's also why fans have "high" as the very first setting after "off." For geared motors, you don't necessarily have that same torque issue because the planetary gearset will give you some torque multiplication. However, the core motor RPM has to be higher since there's a step-down gearing in effect. That multiplier not only affects getting up to speed from a stop, but also accelerating since a, say, 2:1 gearing ratio means double the absolute core RPM difference for the same absolute speed difference vs. a direct-drive setup. Since it would normally take longer to get up to that higher RPM for a given power input, that could give a feel of a laggy response, which is potentially undesirable. To counteract this, firmware programmers will probably just boost the voltage during acceleration so that the "revving" up and down can happen more quickly and response feels immediate.

Also worth noting is that bikes, AFAIK, don't really have a true weight sensor, so they will provide whatever starting torque/power output they need for the upper limit spec'ed mass of bike + rider. So if a bike is spec'ed to carry up to a 275 lb rider (which in engineering-land really means that 325 lbs is safe, but not recommended), and a 130 lb rider gets on that bike, that motor controller is going to accelerate at a level fit for roughly double the overall weight. Now in principle, a torque sensor can negate this since a lighter-weight rider is likely to also put less strain on the crank than a heavier one, so you get a mock weight-based scaling effect that way.

A pain point of cadence sensors is that the need for immediate response is quite possibly what becomes a limiting factor in how smooth they will be. A person's instantaneous pedaling cadence is naturally uneven through the cycle, but in order to respond quickly, they will measure your cadence as soon as possible and just roll with it. If you wait for a full cycle at least, you can use the "average" cadence to get something more accurate, but again, you get a delayed onset of power that people might find too laggy. You could also scale the estimated cadence according to the specific angle since the amount of force people can apply through the pedal stroke is pretty predictable, but you'd need some sort of crank position sensor. Whatever the case, different companies will prioritize the quick response vs. smoothness balance differently and different models of motors will have different gearing ratios and so on.
I get a lot of what you're saying, and there's some good points - like the bike's response to different rider/load weights, and the reason fans start on high.

From what I see, rather than mess around with varied starting voltage, the better controllers recognize where the inputs are coming from (throttle vs. cadence sensor) and it treats them differently. They seem to be using "soft start" for cadence changes, and hard, right now response for throttle input. This will provide the gentle starts required by an e-bike shy/inexperienced hundred pound rider, and the necessary grunt an experienced heavier rider is looking for when crossing a busy road for instance....

The "meat head" programmers, who either have never ridden a bike, or don't realize/care what their programming will be used for, take none of that into account...

The REAL bottom line though, is that it's not hard to improve on what we're getting today (seen clearly with the number of complaints seen regarding low speed handling). In my mind at least, I believe there's a lot of possible sophistication being left on the table right now, and one of the biggest changes we'll likely see in the near future will be right here, in the form of improvements made to the user interface. They will likely be coming fast and furious as the bike industry evolves - and we'll be light years ahead of where we are now when it comes to how "friendly/intuitive" an e-bike controller can be. Riders will become more demanding, and the industry will realize they can't get away with some of the mickey mouse programming available today. -Al
 
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pkchari

New Member
Region
USA
City
Redmond, WA
From what I see, rather than mess around with varied starting voltage, the better controllers recognize where the inputs are coming from (throttle vs. cadence sensor) and it treats them differently. They seem to be using "soft start" for cadence changes, and hard, right now response for throttle input. This will provide the gentle starts required by an e-bike shy/inexperienced hundred pound rider, and the necessary grunt an experienced heavier rider is looking for when crossing a busy road for instance....
Totally agree. I think one manufacturer that really nails it for new e-bike-shy riders is actually Schwinn. Yeah, they're doing it with 250W hub drive motors, but they are taking a cadence sensor and still getting that "natural feeling" power delivery on point. And I say "Schwinn" nails it because they are also selling stuff at a more mass-market price level with e-bikes around $900 and all, which is probably where a lot of new-to-ebikes people might look. I can't say for sure what they are doing, but my educated guess that they are taking average crank speed and giving it that same time of revolution for ramp-up. Whatever they are doing, it works. It feels almost as good as Cannondale (being owned by the same company, I presume they were going for that feel), and they're using a wheel sensor on their hub drive bikes.
The REAL bottom line though, is that it's not hard to improve on what we're getting today (seen clearly with the number of complaints seen regarding low speed handling). In my mind at least, I believe there's a lot of possible sophistication being left on the table right now, and one of the biggest changes we'll likely see in the near future will be right here, in the form of improvements made to the user interface. They will likely be coming fast and furious as the bike industry evolves - and we'll be light years ahead of where we are now when it comes to how "friendly/intuitive" an e-bike controller can be. Riders will become more demanding, and the industry will realize they can't get away with some of the mickey mouse programming available today. -Al
Would love to see this happen, but I'm also enough of a cynic to make Batman look like Rainbow Brite. A common refrain that I've heard from people who own and ride cadence sensor bikes with that classic "on/off" feel is that after some time, you get used to it and it feels normal. As an owner of an Aventon that has this same shortcoming, I can also attest that it is true. My standard approach is to always start off with PAS off and then work my way up as needed, and this has become second nature by now in the same way that shifting gears does. It's my new normal when it comes to riding. That sort of mentality becomes a stopping point for innovation. People just come to accept that this is normal, and when that happens, you get people who don't even see it as an issue. Engineers who try harder to make it feel more natural and make the logic more customizable will just be looked at as finding solutions for non-existent problems.

The riders who likely might become more demanding first are the ones who sit at the high end of the spectrum, and they will always be a tiny market. Sure, you might find more and more improvement up over time at that tier of buyers, but they are already a leg up because they're buying bikes with mid drives, torque sensors, and belt-driven IGHs, and the problems are inherently many times more tractable when technology like that is a given. COVID notwithstanding, the bike market as a whole is not that big, so trickle down of tech is something that just doesn't happen quickly, and I wouldn't be surprised if some of it simply never happens.