CYC PHOTON

Ecyclist said:
Obviously your mind is set. Good for you.;)
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I'm really looking forward to the BikeOn kit. It's in the mail now!

I tried to look at the first of your linked build threads, the Avian, for your Japan trip. Very impressive! But there seem to be a lot of pictures missing from your first posts. People are commenting on stuff that is just not there anymore.
Cycloidal drive is the same as harmonic drive, I assume? Those are becoming popular for telescope mounts, I believe there it's the huge holding torque and the absence of backlash that is interesting.
Your from-the-ground-up approach to an e-bike is certainly inspiring, but for now I'm looking for (and have hopefully found in the BikeOn) an off-the-shelf ready-to-mount drive that I don't have to fiddle with endlessly. If I had learned some machining skills earlier in life, well then... on the other hand it's never too late; we'll see.
 
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I will be following your BikeOn install for sure. But as for kits that you do not need to fool with once installed, IMO any of the CYC kits fit that bill as does TSDZ2 and probably also the DM kits. None of them have an ideal Q factor but it hasn't been an issue for many of us. The TSDZ2... and probably also the DMs... is a bit of bother to update the firmware but you really don't need to do that once you have it working with a FW that you like. CYC FW is dead easy with the app on Bluetooth. Not sure what to expect yet for FW updates with BikeOn. Hopefully with the app via bluetooth.

Gruesome said:
I'm really looking forward to the BikeOn kit. It's in the mail now!

I tried to look at the first of your linked build threads, the Avian, for your Japan trip. Very impressive! But there seem to be a lot of pictures missing from your first posts. People are commenting on stuff that is just not there anymore.
Cycloidal drive is the same as harmonic drive, I assume? Those are becoming popular for telescope mounts, I believe there it's the huge holding torque and the absence of backlash that is interesting.
Your from-the-ground-up approach to an e-bike is certainly inspiring, but for now I'm looking for (and have hopefully found in the BikeOn) an off-the-shelf ready-to-mount drive that I don't have to fiddle with endlessly. If I had learned some machining skills earlier in life, well then... on the other it's never too late; we'll see.
Click to expand...
 
Gruesome said:
I'm really looking forward to the BikeOn kit. It's in the mail now!

I tried to look at the first of your linked build threads, the Avian, for your Japan trip. Very impressive! But there seem to be a lot of pictures missing from your first posts. People are commenting on stuff that is just not there anymore.
Cycloidal drive is the same as harmonic drive, I assume? Those are becoming popular for telescope mounts, I believe there it's the huge holding torque and the absence of backlash that is interesting.
Your from-the-ground-up approach to an e-bike is certainly inspiring, but for now I'm looking for (and have hopefully found in the BikeOn) an off-the-shelf ready-to-mount drive that I don't have to fiddle with endlessly. If I had learned some machining skills earlier in life, well then... on the other hand it's never too late; we'll see.
Click to expand...
Cycloidal and harmonic drives are two different things. Harmonic is low power drive. Cycloidal can be low power, but it can be very high power. They are based on different principals. I hope that your new kit will work for you.
 
Ecyclist said:
Cycloidal and harmonic drives are two different things. Harmonic is low power drive. Cycloidal can be low power, but it can be very high power. They are based on different principals. I hope that your new kit will work for you.
Click to expand...
Thanks! We'll see how it works.

Any way to get those pics restored in your Avian thread?

Harmonic vs cycloidal: now I had to google it. The two drives work pretty similar, but indeed not the same: What Is the Difference Between Strain Wave & Cycloidal Drives These guys think the difference boils down not so much to power/torque capability, but low backlash & high efficiency (harmonic/strain wave) vs robustness & ease of manufacturing (cycloidal).
I didn't know you could use these transmissions for bikes. Splendid work!
 
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In harmonic drive the flex spline has to be very thin to work properly and because of that can't take heavy loads.
It's obvious form just looking at it.
Here you can see high power cycloidal drive.
I'm talking shitload of torque. :oop:


I'm not sure if I still have pics to restore Avian page.
 
Ok, just did a 98F degree Photon ride.

And we were onto something with the RPMs/voltage conversion. I was able to complete the same long climb with roughly the same power levels as my Turbo Vado (620W-720W) by sprinting at 105-110 cadence/crank rpm. This equated to roughly 2000 motor RPM.

The Photon is getting lugged horribly at 80-90 rpm cadence. Unfortunately, I’m a chill guy with a chill cadence of 80rpm. And sprinting up a long climb, sucking in hot Santa Ana winds is not fun.

The only thing I can think of to help with this rider-motor cadence mismatch is to go with the shortest cranks possible and possibly a 36V battery, but that would need to be real-world tested.

So the Photon didn’t melt, and it can still climb in near-triple-digit heat, but you must pedal fast because it was designed for a very high crank rpm. Even at 110rpm, it is most likely badly lugged based on the numbers earlier in this thread, but at 90 rpm you are melting the motor.
 
Were you running it on 52v?

Maybe spinning your way up a hill would be closer to acceptable at 48v if so? this might be part of why you have a bigger problem than the others.

I'm betting i have the same problems on my lightest bike mid drive but we'll see
 
neptronix said:
Were you running it on 52v?

Maybe spinning your way up a hill would be closer to acceptable at 48v if so? this might be part of why you have a bigger problem than the others.

I'm betting i have the same problems on my lightest bike mid drive but we'll see
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Yeah, 52V right now on the Photon.

I don't think you will have problems lugging or overheating the Bikee Lightest motor. It is a completely different beast.
 
So based on what I witnessed today, at 52V you need to stay above 2000 motor RPM in hot weather... which would be about 60% of max unloaded motor RPM. (3350rpm measured by @Epithemeus )

I'll just leave this here:
"On long climbs, Lance Armstrong pedaled a hummingbird-like 100 to 110 rpm while his rivals tended to slow to about 70 rpm."

Hmmm.

All of the competing motors (on premium factory ebikes) are designed for a pedal cadence between 70-90 rpm. I pedal up that same hill at 80rpm on the Vado.
 
Maybe I'm missing something fundamental, but I don't understand your voltage discussion. You make it sound like you could somehow choose motor voltage and current independently, when you can't. Correct me if I'm wrong, but how it works is you supply the controller with a voltage, the controller tries to push a certain current (as told by the throttle) through the motor, and it does push that current at whatever voltage is needed for that until it either hits its own current limit, the battery current limit, or is limited by its supply voltage. For a given load (weight, grade, effective headwind, rolling resistance, other losses) and a given motor there is one current, voltage, motor torque and speed (and thus power) where the bike doesn't accelerate anymore. If you had more voltage, and your are neither at the current limit of the battery or the controller, then the controller could push more current through the motor coils, and make it go a bit faster (or burn up). But you can't change the voltage over the coils independently of the current. So as long as the supply voltage is high enough, the controller will just regulate it down to get the right current, and a higher battery voltage is not going to help.
 
nervagon said:
I don't think you will have problems lugging or overheating the Bikee Lightest motor. It is a completely different beast.
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In fact there will be MORE problems lugging the motor, though it may not overheat. It is essentially a hub motor, so will never run efficiently at lower road speeds. For the bike and terrain in question that might not be a problem and seems to be the intended use of that motor. For where I ride (often in lowest gear and very low speed) the Bikeon wouldn't be producing much assistance at all.

In fact, a real hub motor would be my choice for this type conversion - fully enclosed, with a proven track record, and much cheaper.
 
hindesite said:
In fact there will be MORE problems lugging the motor, though it may not overheat. It is essentially a hub motor, so will never run efficiently at lower road speeds. For the bike and terrain in question that might not be a problem and seems to be the intended use of that motor. For where I ride (often in lowest gear and very low speed) the Bikeon wouldn't be producing much assistance at all.

In fact, a real hub motor would be my choice for this type conversion - fully enclosed, with a proven track record, and much cheaper.
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You seem to be confusing Bikee with Bikeon. I have no knowledge of the Bikeon kit, and I’m speaking from experience with the Bikee Lightest motor. It might be loud, and cumbersome to install, but it doesn’t suffer from the same problems as the Photon.
 
nervagon said:
You seem to be confusing Bikee with Bikeon. I have no knowledge of the Bikeon kit, and I’m speaking from experience with the Bikee Lightest motor. It might be loud, and cumbersome to install, but it doesn’t suffer from the same problems as the Photon.
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We're discussing too many motors in one thread.... ;) But I like it. Easier than hopping around all the time.

Yes, I would consider the Bikeon a type of geared hub motor. It would be interesting to see it in the ebikes.ca motor simulator.

All we know right now is that it supposedly has a nominal starting torque of 55Nm, from which you can compute the slow speed grade capability if you know your weight and wheel size. For 700c, with about 2150mm circumference or 342mm radius, the tractive force is 55Nm/0.342m = 160 N, which means it can push a 220 lbs/100 kg rider & bike (1000 N weight force) up a 16% grade. If the rider puts in another 55 Nm, they can do 32% grades together.

Incidentally I emailed Justin and his helpers about that, but they replied that they are too busy to test the BikeOn in the foreseeable future. I don't think I will be able to measure the relevant motor parameters.

For my application, as a pusher engine up to 20 mph, to
  • prevent getting bogged down by headwinds from 15 mph to 10 mph,
  • up my level speed from 15 mph to 20 mph, and
  • help me up 6% grades at 9 mph instead of 5 mph,
it should work. I will hopefully find out soon.
 
Gruesome said:
We don't know that. Note that I didn't say anything about speed or power. We just don't know without having any motor data beyond starting torque.
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We can infer that simply because the motor RPM will be very low due to the wheel speed being very low, and all the efficiency curves are similar shape. Poor efficiency = more heat. We know the RPM will be low because nobody pedals up 16% grades at speed. That's the biggest tradeoff with hub motors vs mid drives.
 
raylo32 said:
IMO this depends on what kind of biker you are. I have been a hard core roadie for decades so things like close gear ratios, having the bike react smoothly and proportionally to my input are paramount. Torque sensor is the only way to achieve that with an e-bike. IOW you need a TS to make it ride like a real bike. If you are more of a recreational biker and don't have that need burned in, a PAS motor might work just fine for you, since you really won't know what you are missing. And as for hub motors, sure they are simpler, but they mess up center of gravity and bike handling to some extent.. especially for front hubs... which might be just fine on a heavy commuter bike ridden on flat terrain. Whereas mid motors add the weight down low and in the
raylo32 said:
IMO this depends on what kind of biker you are. I have been a hard core roadie for decades so things like close gear ratios, having the bike react smoothly and proportionally to my input are paramount. Torque sensor is the only way to achieve that with an e-bike. IOW you need a TS to make it ride like a real bike. If you are more of a recreational biker and don't have that need burned in, a PAS motor might work just fine for you, since you really won't know what you are missing. And as for hub motors, sure they are simpler, but they mess up center of gravity and bike handling to some extent.. especially for front hubs... which might be just fine on a heavy commuter bike ridden on flat terrain. Whereas mid motors add the weight down low and in the center so don't really have any impact, other that the added weight.
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raylo32 said:
IMO this depends on what kind of biker you are. I have been a hard core roadie for decades so things like close gear ratios, having the bike react smoothly and proportionally to my input are paramount. Torque sensor is the only way to achieve that with an e-bike. IOW you need a TS to make it ride like a real bike. If you are more of a recreational biker and don't have that need burned in, a PAS motor might work just fine for you, since you really won't know what you are missing. And as for hub motors, sure they are simpler, but they mess up center of gravity and bike handling to some extent.. especially for front hubs... which might be just fine on a heavy commuter bike ridden on flat terrain. Whereas mid motors add the weight down low and in the center so don't really have any impact, other that the added weight.
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Weren't torque sensors more intended for offroad climbing trough huge rocks and such in general? Cadence sensors might also be important for roadies due to ability to help keeping constant pedalling RPM while not losing momentum on hills compared to torque sensors which respond to inherently uneven power delivery from legs resulting in current fluctuations as seen on wattmeters such as toolkit rc WM150 (not sure about resolution of eggrider data logging yet).
 
sysrq said:
Weren't torque sensors more intended for offroad climbing trough huge rocks and such in general?
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Not all all. The use of a (good) torque sensor makes the additional motor power seamless, the rider just feels stronger. Cadence sensors don't do this, since they don't reflect the rider's input power.
sysrq said:
compared to torque sensors which respond to inherently uneven power delivery from legs resulting in current fluctuations as seen on wattmeters such as toolkit rc WM150 (not sure about resolution of eggrider data logging yet).
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Not at all. For example, the Photon app allows to to set the time it takes for power to ramp up and fall away. It smooths out the variation in rider power through the stroke. Power meters are able to measure this detail, and maybe the Photon sensor can, but it doesn't need to. We are not interested in the minutiae of the riders physiology, performance or technique.

When riding the Photon, the only difference I feel between being powered and unpowered, is that unpowered, (apart from not having a little overrun) it feels exactly like the brakes are dragging. The application of power feels really very natural (actually, better than OTS ebikes I've ridden), and way better than Bafang.
 
hindesite said:
Not all all. The use of a (good) torque sensor makes the additional motor power seamless, the rider just feels stronger. Cadence sensors don't do this, since they don't reflect the rider's input power.

Not at all. For example, the Photon app allows to to set the time it takes for power to ramp up and fall away. It smooths out the variation in rider power through the stroke. Power meters are able to measure this detail, and maybe the Photon sensor can, but it doesn't need to. We are not interested in the minutiae of the riders physiology, performance or technique.

When riding the Photon, the only difference I feel between being powered and unpowered, is that unpowered, (apart from not having a little overrun) it feels exactly like the brakes are dragging. The application of power feels really very natural (actually, better than OTS ebikes I've ridden), and way better than Bafang.
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All I know that TSDZ2 on 1-3 PAS levels felt like it makes pedalling somewhat harder while level 4 felt like motor takes over and there is no pedalling resistance especially in granny gears when climbing. It was hard to decide how much should I exert myself before 17% hills otherwise the motor wouldn’t help when feeling tired.
BBSHD cadence sensor feels like having constant tail wind which allows you to choose how hard to push the pedals when programmed to 50% RPM max and 50% current max. Now it’s high intensity pedalling without the motor on flats, cadence PAS in headwinds and WOT on 17% hills at 100% RPM.
 
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I installed the new firmware, and I've got good news. The voltage reading on the SW102 display is fixed. I wonder what other small fixes might be hiding in this new update. Haven't had a chance to ride yet. Maybe tomorrow... and tomorrow will be really hot... probably over 100F.
 
sysrq said:
All I know that TSDZ2 on 1-3 PAS levels felt like it makes pedalling somewhat harder wise level 4 felt like motor takes over and there is no pedalling resistance especially in granny gears when climbing.
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Photon is totally different - at least how my Photon is set up. Even at the highest assist level, in the lowest gear, the rider is always contributing to get the power multiplication. And I know this from heart rate monitoring, the effort is real.

The other interesting aspect is that although the motor power is smoothed or filtered, it still generally reflects the power put in by the rider. My previous tires were not particularly good, and on steep (20%+ grade) climbs would be on the edge of losing traction. The extra variable effort contributed by the rider was really noticeable, since the tires would often squeak slightly during the pedal stroke on the wet grass, but usually not completely break traction. The variable rider input acting like a very basic traction control.
 
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