LOL Are you serious? I explained in detail the difference between speed based and power based PAS and even provided references to other material that discusses it. Just go back and read my previous several posts. AHicks is correct that the sensor hardware itself is the same.
Espin Flow pedal assist power levels
- Thread starter rbermanaz
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BigNerd
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To quote The Princess Bride, I don't think this means what you think it means.
BigNerd
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And what I'm trying to say is it is both.
I explained this in the Cadence vs Torque thread.
Each level has a power limit and a speed limit.
The power limit is for the maximum power the motor will get, the speed limit is if the bike is going at that speed, to only provide nominal power. That's what my test was for.
If the Sport was only speed based, I would get 100% power available at PAS 1 until I reached the speed limit of PAS 1... that is not the case... the power I get varies by the pedal cadence.
And I know there are power limits at each level because at PAS 1, the number can only get to a certain number no matter how slow I pedal, at PAS 2, that number is higher.
I don't think you are understanding the interaction between cadence, speed, power and the levels.
You're not understanding the difference between speed vs power based PAS. Of course, all assist systems have to apply power to move the bike, and that amount of power can vary depending on the programming. That doesn't mean it's not speed based. Power based will maintain relatively the same amount of power in a given assist level regardless of speed, and the Espin doesn't do that. The key to the difference is whether power is dropped when you hit a specific speed. The newer Ride1Up bikes and newer Radbikes do NOT drop the power way down when they hit a specific speed because they are not programmed to do so in current generation bikes, only the older (or much older) models. So with current models, it's easier to pedal faster than the baseline speed with no need to increase the assist level. For the Espin, it looks like they still have a speed limit in place with each assist level where the power is dropped significantly once you reach it, like hitting a wall, so you really need to bump up the assist level to go faster, which you said so yourself. That's too bad, but it is what it is.
BigNerd
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There is flaw in this that I don't think you are seeing.
A cadence sensor reduces power the faster you pedal. If you are pedaling fast enough to exceed the speed for that PAS level, the power has already dropped.
Now, if your saying that these newer systems do not reduce power based on pedal cadence and are putting out the maximum power for that PAS level all the time... do you see what kind of issues that could cause? At the top of my head, battery burn. Maybe this is how other bikes work but that's not the case with my Espin Sport and I don't have any "dread" over it.
It actually depends on the program, not the sensor itself, but the power based cadence PAS system will maintain power rather than cutting off at a certain speed like hitting a wall. There is no such thing as "speed for that PAS level" on the power based PAS systems like the Ride1Up and Radbike cadence based PAS systems. That only applies to the speed based cadence PAS, as the Espin apparently has.
With the Sport speed based cadence PAS, reaching a given speed is like hitting a wall, so you end up changing your assist level higher. The power based assist is more rewarding when you want to get more exercise and pedal harder because it will continue to provide the same power assistance so that your speed increases more. It's more smooth, less clunky, as others have described the speed based cadence PAS in the other thread. With the power based PAS, if you want to save battery, you simply use a lower assist level while pedaling harder. Easy peasy.
It's no wonder you haven't followed the cadence "speed" vs. "power" discussion if you are confusing it with a torque sensor PAS system. The torque sensor system measures how much pedaling force is applied to the pedals in calculating how much power to supply to the motor. The cadence sensor system is more like a switch checking whether the pedals are moving or stationary, with no measurement of pedaling force. You may be confused because I mentioned "pedaling with force" in the test steps, but that is to push the bike beyond a specific PAS speed of the Espin, and it is in no way related to the bike measuring your pedaling force as it is done in a torque PAS system. It's apples and oranges, and it shows you still aren't following the discussion despite all the details I have provided. I'm thinking it's hopeless.
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BigNerd
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Again, that's now how a cadence sensor works. It reduces power based on how fast you pedal. So if you are pedaling fast enough, the power has already been dropped... not maintained.
That may be true, but if you there is a cadence/power inversion relationship, it may not have that much effect.
I don't think this is right... think about it in terms of gearing.
I don’t have a dog in this race as the bike works well for me, but I don’t think this could be correct. Why? If you reduce to a low gear ratio you can pedal like mad and not exceed the power of the PAS setting. If it varies based on pedal speed then the gear ratios would play havoc with it. My 2 cents.
That's not true regarding the better power based PAS systems that I've been talking about reducing power at higher speed. I keep telling you that. Unfortunately, that's not the case with your Sport. That's too bad, but the other systems don't have that problem of running up against a wall and dropping power when you try to pedal to a faster speed (I'll avoid the word "force" here so you won't get confused again thinking it has anything to do with sensing pedaling force with torque sensors lol).
All I can say is "lol" to that. If you don't understand something, you really should read everything I posted again, because I've spent quite a bit of time trying to explain it to you, in multiple threads now, and you keep talking past me, speaking in circles, and repeating the same tired false statements about how it works.
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BigNerd
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So criticisms aside, what I believe the Espin Sport has is a power based system with a speed limit at each level. That is not the same as a speed based system as explained by a post in the other thread (100% power at each level limited by speed).
Do you still think the cadence sensor is just an on/off switch?
Do you still think the cadence sensor is just an on/off switch?
The Espin is speed based if it cuts power down from 400 to 20 watts when you hit a certain speed as your test showed. Power based cadence PAS maintains power up to the class speed, and the Espin does NOT do that in any meaningful way, since it drops it way down to 4% power at a speed threshold, therefore it cannot be called power based. Speed based cadence PAS applies power up to a specific speed, which is what the Espin does before power drops way down to 4%. So, putting 2 and 2 together, the Espin is not power based cadence PAS. It's speed based. The fact that there may be an early acceleration surge, or the fact that there may be some risidual power leaking through beyond the speed threshold, doesn't make it some sort of special hybrid PAS system when it's still being limited by speed in a given PAS level, that the power based PAS bikes are not limited by.
It basically functions as one as per Juice bikes reference and the other thread. You will see cadence sensors commonly and frequently described as such. If the pedals are rotating, PAS power is engaged. If you stop pedaling, PAS power is turned off. Obviously the controller/software comes into the mix in regulating this as the sensor doesn't exist in a vacuum.
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McCorby
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This is where I think you are hung up......with a speed based system, it is vehicle speed, not pedal cadence that reduces motor output.
McCorby
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Yes. It doesn’t matter how slow or fast you’re pedaling. This is where the term “ghost pedaling“ comes from. The motor is either on when you pedal or off when you stop. With a simple speed based system, the motor is providing 100% output no matter how fast or slow you’re pedaling until the max vehicle speed for the PAS level is reached. With a power based system, the same holds true regarding the operation of the cadence sensor. The difference is that the PAS level determines the percentage of power that the motor delivers, not the vehicle speed the motor will assist to. Again, it doesn’t matter how fast or slow you’re pedaling.
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BigNerd
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I don't think that's correct, at least on the Espin Sport. And Kevin from the R1U video says the same thing... that the cadence of the pedaling controls the power output (same with the Evelo site).
The speed (cadence) you pedal controls how much power goes to the motor. That was the test I did on a flat surface, pedal slow, the P number is higher, pedal faster, the P number is lower.
Why does a cadence sensor need more than a few magnets if it just needs to know if you are pedaling? Because it also needs to know the cadence... why even call it a cadence sensor?
BigNerd
Well-Known Member
That's not what the test bore out.
Ignore what the number represents from the P display. I have no idea if that's current or watts or whatever whatever. Just look at how it varies. It did not drop from 400 to 20 once I reached a 10mph. It dropped from 400 to different numbers depending on how fast I pedaled. That was the first test, to see if cadence affected power output.
Then, once I got over 10mph, even if I pedaled slower or faster, it did not vary anymore, that's when it stayed at 20 or whatever. That was the second test, to see if over the 10mph limit, if power output would be affected by pedal cadence.
If it were purely speed based, the number would stay at 400 the whole time as long as I was pedaling no matter the cadence. In fact, it would be higher because both you and McCorby says it puts out 100% power until I hit a speed threshold. That does not make sense... because why would have to go up to PAS 2 or PAS 3 if I'm going up a hill and not hitting the 10mph PAS 1 speed limit? Because I need more power, so that means there is a power threshold at each PAS level too. The testing also bore this out because 400 (this number could actually be higher because I didn't write them down) would be the max the P number could get to in PAS 1. I had to move up to PAS 2 to get it higher (I think over 1000).
This is not efficient. What are the PAS levels for if 100% power happens at any level? Even more so if there is no relationship to cadence. This would mean at PAS 1, the start up "jump" would be just the same as at PAS 5. I posit that at least in the Espin Sport's case, there has to be a power threshold at each PAS level... and my testing indicates that.
McCorby
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This may be the case for your bike, but the speed based systems that I’ve ridden behaved as I described.
Edit: It also makes no sense to me why power would be reduced based on you pedaling faster, as you describe. Why would you want it to behave like that? So if you downshift and pedal faster, the motor will provide less power? It makes more sense that power is being reduced because you reached the maximum vehicle speed for a given PAS level.
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BigNerd
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Let's do this outside of gearing because that's another variable.
When you first start pedaling, your cadence is slow, thus you need more power. As you start pedaling faster, power is reduced because you don't need as much power. That's how I understand a cadence sensor should work.
I think there is a misconception here that a cadence sensor means the faster you pedal, the more power you get.
Now let's add gearing.
When you are pedaling at a certain cadence and you want to go faster without changing your cadence, what do you do? You shift up right? But there is that span of time where you cadence is slower because you are in a higher gear, that's where the motor will increase power and continue to do so to keep at your higher speed but making it easier for you to pedal.
Now, what happens if you downshift and pedal faster... yes... the motor will reduce power. But why are you downshifting to pedal faster? Maybe going up a hill? With this cadence setup, you don't have to downshift. Your cadence will slow because it's "harder" to go uphill and that will increase power to the motor which also makes it easier to pedal. It's an inverse relationship that makes sense.
BigNerd
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Which bikes are you referring to? I'd like to ask around to see how those perform.
