Torque sensor vs Cadence...

[BigNerd]

An early surge of power provided by the controller to increase acceleration, even if it's different at PAS1 vs PAS2 (yet not proven) does not mean that it's not a speed based assist. It's still speed based because it drops way down at a specific speed while power based PAS will maintain the same power as you increase speed. Ride1Up and others have moved away from the speed based assist (that Espin uses) to power based assist. Maybe you can get a different display and controller to change the way your Espin works since you said that's not what you want in your earlier post.

Where did I say it's not what I want?

 

[BigNerd]

You've been posting a lot of misinformation, I will say that. It appears you are not really wanting to learn anything, and it's coming across as trolling. You're just trying to get people frustrated in repeatedly explaining things to you as you go in circles, keep talking past me, and use the same old tired false arguments.

Please direct me to my misinformation? I may have confused a video with a website but this all started with me reporting the results of my testing trying to figure out what the difference is between speed based and power based systems. If you want to accuse me of things that's on you but your posts can be just as circular as mine.

Here are some things that you posted that are misinformation:

1. Cadence sensor is just an on/off switch.
Not true... even by just the name of it. It measures cadence and that controls how much power the motor gets. I have posted many details on how my tests demonstrates that but you ignore it. I've posted a site that explains that and you've ignored it. I'm talking to you... not past you.

2. Espin uses a speed-based system, the fact that the power drops off at a certain speed proves this.
That just proves that in addition to having a power threshold at each PAS level, it also has a speed threshold. As I told you, the power output on the Espin fluctuates with the cadence of my pedaling (which proves #1). If there is 100% power until I reach a certain speed, that would stay at a steady output during the entire time I was under that speed limit no matter what my cadence was... that was not the case.

Now, if you want to change the definition of what a speed-based system is (or clarify it), which is what I asked in the first place, then I can agree with you.

 

[GenXrider]

Again, it's power-based because each PAS level has a power limit just like power-based systems. Not sure why you aren't getting that.

Additionally, there is a speed limit for each PAS level but according to McCorby's definition, speed-based systems have 100% power available at all PAS levels. That is not the case with the Sport. The power fluctuates in correlation to pedal cadence. The max output power at each PAS level is higher for each level.

I am not arguing what is speed-based and what is power-based... just that based on the definitions from McCorby, the Sport has both.

I'll break it down to these two questions, to see if that makes it any easier for you to understand.

Does the Sport maintain a relatively consistent power level in a given assist level at any speed up to the bike's max speed? If the answer is yes, then it's power based assist.

Does the Sport drop power completely or significantly in a given assist level when it approaches/reaches/exceeds a specific speed? If the answer is yes, then it's speed based power assist.

There you have it. Answer these questions, and you will know what type of cadence based PAS system it uses.

 

[McCorby]

Additionally, there is a speed limit for each PAS level but according to McCorby's definition, speed-based systems have 100% power available at all PAS levels. That is not the case with the Sport. The power fluctuates in correlation to pedal cadence. The max output power at each PAS level is higher for each level.

I’m not questioning your bikes operation/behavior as I have not ridden it. For a few of the one’s we test rode more than 2 years ago, the salesman told us the assist level determined the maximum assist speed, and not the actual amount of power output. And that’s how they appeared to behave when we test rode them. This included my observation that pedal cadence didn’t seem to have an effect on power output.

As for the specific models we tried, I honestly can’t remember. The dealership had several manufacturers. We were shopping for a bike for my girlfriend and rode several. I know she jotted them down at the time. I’ll ask her if she remembers or still has her notes. One manufacturer that I do remember testing was an iZip, but I’m pretty sure that one had a Suntour hub motor with torque sensing, so that one doesn’t apply to this conversation.

 

[BigNerd]

Does the Sport drop power completely or significantly in a given assist level when it reaches/exceeds a specific speed? If the answer is yes, then it's speed based power assist.

Ahhh... the answer to this question might help you more than me.

Not always. On a flat surface in PAS 1, if I gear up or down, even if I'm above the 10mph limit, power output will vary but not drop significantly. Where it did drop significantly was when I was going downhill over 22mph which is the PAS 3 or PAS 4 speed limit, but I was only in PAS 1. If I was in a higher PAS, I might not have seen that big a drop but I think I will test that again.

I also noticed this before I did the P number output test because when I would hit 12mph (over the 10mph limit) in PAS 1, if I turned it down to PAS 0, it was harder to pedal so there was power assist but limited.

I will test this again as I may be wrong.

 

[GenXrider]

Not always. On a flat surface in PAS 1, if I gear up or down, even if I'm above the 10mph limit, power output will vary but not drop significantly. Where it did drop significantly was when I was going downhill over 22mph which is the PAS 3 or PAS 4 speed limit, but I was only in PAS 1. I

Previously you stated it dropped significantly from 400 down to 20 on a flat surface at just 10 mph.

Now what about the speed limiter? Well, on a flat surface, when I hit 10mph, that number drops down to like 20.

Reference: https://electricbikereview.com/forums/threads/espin-flow-pedal-assist-power-levels.35796/post-386248

 

[GenXrider]

I also noticed this before I did the P number output test because when I would hit 12mph (over the 10mph limit) in PAS 1, if I turned it down to PAS 0, it was harder to pedal so there was power assist but limited.

That goes back to what I was telling you a few times before. PAS power being applied even after you exceed the baseline speed does NOT "go to waste" as you had thought before, it still aids in allowing you to go faster in combination with your muscle power. In the example above, you saw that for yourself. Glad to see that.

 

[BigNerd]

I finally got a chance to ride again yesterday and it still feels like cadence (pedal speed) on my bike does control power output.

In PAS 1, when I first start pedaling (slow), the P unit (still have no idea what that is indicative of, watts/amps/?) goes up to about 600-700 (fluctuates). As I pedal faster, the P number goes down to around 100-400 depending on how fast I pedal and goes back up if I slow my cadence. And this is around 5-7mph well under the 10mph cutoff for PAS 1. As I get up to 9mph, the P number drops down to below 100 even as low as 14... and then at 10mph, the cutoff... as long as I'm over 10mhp, the P is 20 and stays there (I tested this going downhill too). So that confirms I may have been mixed up in reporting how that works when I go over 10mph.

The interesting thing, is that even over 10mph (say like 12mph), that 20 is still giving me enough assist so that I can feel it, because if I drop down to PAS 0, it's harder to pedal. So in regards to that power dropoff issue with speed based systems, I'm not sure if with a true cadence-to-power system, it's that much of an issue. As I'm approaching 10mph, the P number has already dropped below 100 because I have to pedal faster to get to that speed, once I go over 10mph, my human power is exceeding the PAS 1 assist, so on a non ebike, when I'm exceeding my current gear ratio, what do I do? I gear up... same thing with my ebike, I "gear up" to PAS 2. Not really a big deal to me (and maybe only to me).

Now, there is the possibility that these power assist levels under 10mph in PAS1 could be speed based and I'm only thinking it feels like it's cadence based. For example, once I hit 5mph, the power assist drops and then at 6mph, 7mph, 8, mph etc until 10mph. Because as the bike moves faster, the P number drops... but I'm also pedaling faster so how do I know it's not cadence instead of speed. So to figure this out I went up an incline... if it were truly speed based the P number at 6 or 8mph would be the same number going uphill as on a flat surface... it wasn't. It seemed to be the speed of my pedaling that increased or decreased the P number.

And again, that's not definitive, that's how it felt to me and what the P number was reporting back so I'm open to being wrong.

 

[AHicks]

The "P" thing you're seeing sure looks & acts like watts (P= amount of power?).

Speed based is about the bike's speed. With the fact your power is dropping to nothing over 10mph shows that perfectly. So there's little doubt you are talking about a speed based system. The cadence speed may be playing into it a bit, but I think you're going to find this is an mph thing.

That "20" indication could be the amount of power that is used for the controller's internal housekeeping. Probably not going to your motor at all.

Regarding "cadence based", there are speed based controllers, there are power based controllers (where the amount of power (P?) doesn't change no matter your speed), and then there are torque based systems. Those are the ones that add/subtract power according to how hard you are pushing on the pedals. There is no "cadence based". Not that I'm aware of anyway....

Ride the bike. Enjoy it while you get to know it. If it's pissing you off for any reason when you get a few miles on it, do what it takes to FIX IT! -Al

 

[BigNerd]

The "P" thing you're seeing sure looks & acts like watts (P= amount of power?).

Speed based is about the bike's speed. With the fact your power is dropping to nothing over 10mph shows that perfectly. So there's little doubt you are talking about a speed based system. The cadence speed may be playing into it a bit, but I think you're going to find this is an mph thing.

That "20" indication could be the amount of power that is used for the controller's internal housekeeping. Probably not going to your motor at all.

Actually it does. When I stop pedaling or pedal backwards, the P number drops to 0. If I start pedaling again in PAS 1 and I'm going over 10mph, it's goes to 20 and I can hear/feel the motor.

Regarding "cadence based", there are speed based controllers, there are power based controllers (where the amount of power (P?) doesn't change no matter your speed), and then there are torque based systems. Those are the ones that add/subtract power according to how hard you are pushing on the pedals. There is no "cadence based". Not that I'm aware of anyway....

Ride the bike. Enjoy it while you get to know it. If it's pissing you off for any reason when you get a few miles on it, do what it takes to FIX IT! -Al

Actually, I have no issues with it whatsoever. If it is indeed what is called "speed-based", the "dreaded" cons that have been bandied about it don't really exist in my usage... and I've had it for about 6 months and hundreds of miles.

Seems to work perfectly for me, when I go over 10mph and I want to go faster, I up to PAS 2 and/or gear up... "easypeasy".

I think what I'm getting at is that some people don't want to buy a cadence-sensor system that is "speed-based" but I don't see why not and it shouldn't dissuade other prospective buyers. I can agree torque sensor systems probably feel more natural (which is why many prefer mid-drive bikes) but there are many posters I see here who like the cadence-sensor setup, especially for recreational riding (which I guess is what my riding is... 15-20miles per ride?).

 

[AHicks]

I think what I'm getting at is that some people don't want to buy a cadence-sensor system that is "speed-based" but I don't see why not and it shouldn't dissuade other prospective buyers. I can agree torque sensor systems probably feel more natural (which is why many prefer mid-drive bikes) but there are many posters I see here who like the cadence-sensor setup, especially for recreational riding (which I guess is what my riding is... 15-20miles per ride?).

The bottom line here is that you are happy with it. Makes little difference what I think, or anyone else thinks. Makes no sense to get into why others don't like it.

That said, in my experience, there is little doubt there are better systems available, especially when it comes to low speed control. I think that maybe if YOU spent some time with either the power based cadence, or the torque based cadence bikes, you would be a believer as well. If nothing else, you would have a better/clearer understanding of the other type systems - like them or not.

Kind of like a car with no power brakes, power steering, power windows, no cruise control, and no power seats when you've never had a car WITH all the bells and whistles. If you've not been spoiled by them, it's just not something you would miss. The car is 100% functional without them.

You know I've just received a new bike a few days ago, and neither me nor the wife are happy with the controller programming. Yes, it's a speed based system. That bike doesn't have 10 miles on it yet, and it's currently down, it's guts hanging loose rather ungracefully, waiting for it's new guts (controller) to arrive from China. If everyone thought speed based controllers were completely satisfactory for their use, or they should be, you might wonder why I'm taking the time, trouble, and money, to install a power based controller. Is it because the original speed based controller doesn't work? Nope. It's because the wife and I have become completely spoiled while riding bikes with power based controllers (that I installed) for years now. For us, knowing that something we both like MUCH more, is available and "do-able" we are going that route. Let's say I got used to the car with all the bells and whistles.... -Al

 

[cldlhd]

The bottom line here is that you are happy with it. Makes little difference what I think, or anyone else thinks. Makes no sense to get into why others don't like it.

That said, in my experience, there is little doubt there are better systems available, especially when it comes to low speed control. I think that maybe if YOU spent some time with either the power based cadence, or the torque based cadence bikes, you would be a believer as well. If nothing else, you would have a better/clearer understanding of the other type systems - like them or not.

Kind of like a car with no power brakes, power steering, power windows, no cruise control, and no power seats when you've never had a car WITH all the bells and whistles. If you've not been spoiled by them, it's just not something you would miss. The car is 100% functional without them.

You know I've just received a new bike a few days ago, and neither me nor the wife are happy with the controller programming. Yes, it's a speed based system. That bike doesn't have 10 miles on it yet, and it's currently down, it's guts hanging loose rather ungracefully, waiting for it's new guts (controller) to arrive from China. If everyone thought speed based controllers were completely satisfactory for their use, or they should be, you might wonder why I'm taking the time, trouble, and money, to install a power based controller. Is it because the original speed based controller doesn't work? Nope. It's because the wife and I have become completely spoiled while riding bikes with power based controllers (that I installed) for years now. For us, knowing that something we both like MUCH more, is available and "do-able" we are going that route. Let's say I got used to the car with all the bells and whistles.... -Al

Let me know how you make out with the controller swap and, if you don't mind, how much it costs. Not saying I'm going to do it but it's nice to have the option

 

[AHicks]

Let me know how you make out with the controller swap and, if you don't mind, how much it costs. Not saying I'm going to do it but it's nice to have the option

I went with the KT20a controller (should be plenty for the 500w motor, giving it up to 1000w for short bursts if set up to do that...), and sort of a deluxe color display (KTLCD8H). Those parts, a couple of cables to simplify the install, and a different thumb throttle that will plug right in to the new system are about 175 bucks, including an "expedited" freight charge of 40 buck or so to hurry things along.

To make a confusing situation worse, you have to be careful to order the correct controller and harness (9 wire) to allow control of the headlight/tail light from the display. They're sold both ways... with light, and without. Check out the link. I've done business with these guys several times and they've done well for me. They actually have a pretty good reputation. Note the accessories listed on the right will plug right in with no mods required, making for a simpler install. I'll get into this further when it's all up and working so others can follow if they choose to. Right now, all I know for sure is that it works on paper.... -Al

36V/48V 500W 20A 6Mosfet Waterproof Sinewave ebike Electric bicycle Brushless Controller fit KunTeng KT Series LED LCD - PSWPOWER.com

2020.pswpower.com

 

[Lightning P38]

Not all cadence sensor software is created equally, so there can be quite a difference from a practical stand point from one bike to the next. This is one of the reasons you'll hear that riding a bike before buying it is a good plan.



P-38 has done a nice job describing "speed" based cadence software. You can see that the different PAS (pedal assist) levels must be changed to change your speed.

The "other" major type of cadence sensed PAS is WAY different, and offers a much more normal experience to my way of thinking. It does this by allowing a certain amount of power to the motor, depending on PAS level chosen. This amount of power doesn't change at ANY speed. If you want more "assist" you dial up the PAS level and it supplies more power to make it easier to pedal. You want to "ghost" pedal with no effort? Set the PAS as required.

For instance - in PAS 1 my bike will have less than 100 watts available for the motor to assist you. It actually varies if you look at the watt meter, bouncing around from about 65 watts up to 100 (keep in mind the controller uses about 50 watts for internal housekeeping), but you feel none of this. It's super smooth, with no jerky on/off as your speeds change. Lets say you make a corner, and the wind direction changes to something hitting you in the face, making it more difficult to pedal. Bumping up to PAS 2 doubles the available power (to 180-200 watts or so), cutting the effort to maintain the SAME speed you were going by 1/2. Hills the same way, or maybe the pavement turned to grass. Set the PAS level for the effort you want to put into pedaling - up to level 5, and it just adds the power you want - no more - and speed has nothing to do with it. Going faster takes more effort, so you dial up the PAS level to reduce the effort to what you are looking for.

I think my pas system is like yours AHicks.....I was just showing the max speeds that result from my pas level selection. As I increase the pas level my speed increases as the power to motor increases, as I don’t push less hard on the pedals as I increase the pas Level. It is a very seamless system. I like the cadence system, perhaps because I can now anticipate what it will do and it is very predictable. After 600 miles of riding I have no complaints about smoothness or matching my power output seamlessly. I can only put about a max of 100 watts of power from my body. I estimate I cruise at about 80 watts of body power. So any increase in electric power will increase my speed, as I keep a constant body power output.

The only thing I don’t care for, is that when coasting, mileage is not recorded nor speed displayed. But I can ghost pedal if I remember too.....but it is not a big issue, as having pedaled miles recorded is not something other bike computers offer...lol.

And the power boost at pas 4 and 5 is simply amazing.....being able to cruise again at 20 mph is a smile every mile. And hitting 28 mph in downtown traffic is awesome.

 

[AHicks]

I think my pas system is like yours AHicks.....I was just showing the max speeds that result from my pas level selection. As I increase the pas level my speed increases as the power to motor increases, as I don’t push less hard on the pedals as I increase the pas Level. It is a very seamless system. I like the cadence system, perhaps because I can now anticipate what it will do and it is very predictable. After 600 miles of riding I have no complaints about smoothness or matching my power output seamlessly. I can only put about a max of 100 watts of power from my body. I estimate I cruise at about 80 watts of body power. So any increase in electric power will increase my speed, as I keep a constant body power output.

The only thing I don’t care for, is that when coasting, mileage is not recorded nor speed displayed. But I can ghost pedal if I remember too.....but it is not a big issue, as having pedaled miles recorded is not something other bike computers offer...lol.

And the power boost at pas 4 and 5 is simply amazing.....being able to cruise again at 20 mph is a smile every mile. And hitting 28 mph in downtown traffic is awesome.

That mileage not registering when coasting is because the gear driven motors are clutched and stop to prevent drag.

Is this a Bolton conversion? If so, there's a fix to your issue here. It might be a wrong setting, or that you may need an external speed sensor (cheap, easy). -Al

 

[Terry777]

Even if you can only test one kind it will give you a feeling for what the group are talking about. You may also love it or hate it too which will help. Try and even just get a go on one and ask as many questions as you can. Some guys will happily let you have a go, some won’t. If you explain your problem that may help too. Loads of people who have ebikes have been right where you are now so understand.

Hope you get some help soon bro.

 

[Lightning P38]

That mileage not registering when coasting is because the gear driven motors are clutched and stop to prevent drag.

Is this a Bolton conversion? If so, there's a fix to your issue here. It might be a wrong setting, or that you may need an external speed sensor (cheap, easy). -Al

I added the bolt on kit from ebikekit to my recumbent bike, so I didn’t have to go with an upright ebike.

I am not aware of a setting option for this. I just use Strava on my iphone to record my mileage, and amount of climbs, as it gives more data than a cycle computer does. At my age I am more interested in the mileage than the speed, so Strava is an easy fix, as long as I remember to turn it on....


I really like my setup with my two wheel recumbents. I bought a second bent with full suspension, so my ride will be smooth, and I can climb hills nicely with it. I just need to transfer the kit over to the full suspension bent...and have the snow melt away. A new paved section of trail near my house was just completed this year.

I am toying with the idea of adding an ekit to my trike, to ride in the snow and ice, but not sure I want to ride when it is that cold out. Then I would have to get a fairing, and then a sock, and then I would want a suspension trike....once you start, it is hard to stop.

I spend my spare time fixing up donated bikes, that our bike club then gives away free to kids. The club has a double car garage full of bikes to fix up. Best I tinker with those bikes than my trike.

Al, thanks for your comments.

 

[FuriousATG]

Are there any significant trade offs in repairability of torque vs cadence sensors?

 

[JES2020]

Are there any significant trade offs in repairability of torque vs cadence sensors?

The cadence system is relatively simple, universal and cheap to replace $18 . Consisting of a wheel that fits on the BB spindle and a sensor that reads the speed of the magnets on the magnet wheel, as they pass.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwiJyrbJ0un4AhUUk2oFHS1ZAT0QwqsBegQIMRAB&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D3Ev8v9CtEEs&usg=AOvVaw0zRuhKRVnx9SPZCNB5YW9L

You can buy magnet wheels that snap together on the spindle, eliminating the removal of the crank arm.

Latest Design Torque Sensor Simulated Pedelec Assistant /Split type left PAS | eBay

High, middle and low gears of imitation torque boost of switch gears and gear indicator display, with. 4. 6Km/h boost function, and the boost light is blinking during boost, it can be used by the rider during.

www.ebay.com

The torque system is significantly more involved to replace, has more complexity and more expensive.

I use the cadence and it performs very smoothly, so much so that, I would not even consider a torque sensor.

 

[fooferdoggie]

I use the cadence and it performs very smoothly, so much so that, I would not even consider a torque sensor.

till you try a high quality torque sensor don't name that statement. I have no delay in power I push I ahve instant power and it feels natural.