CYC PHOTON

[raylo32]

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.

Thanks for all the comments!


Obviously I do not know whether I really need torque sensing. Maybe constant power would be just fine.

 

[Gruesome]

Again, thanks a lot for all the comments! It's pretty much back to square one right now. For now I'm replacing the bracket on the Roadlite.

 

[hindesite]

Again, thanks a lot for all the comments! It's pretty much back to square one right now. For now I'm replacing the bracket on the Roadlite.

My bike had a LBS fitted warranty upgrade to a SRAM DUB BB, the left bearing had failed at <500km. I'm fairly sure whoever installed it didn't know about preload and just overtightened during installation. I just bought a cheap ZTTO replacement, just in case, but the Photon is permanently fitted there for now

 

[branchat]

Mon cyc photon LCD et contrôleur morts, axe tordue j'ai arrêté a l'axe je suis pas assez riche, et le moteur a très peu rouler...je suis retourné chez bafang le moteur a 5 ans et il est comme neuf. ..

 

[smitty2k1]

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.

I had similar concerns but went with a Grin All Axle V3 on my bike and am very happy with the performance. A kink or two still to work out but no reservations about the rear hub motor.

That said it's a longtail cargo bike, so not quite apples to apples.

 

[Gruesome]

Mon cyc photon LCD et contrôleur morts, axe tordue j'ai arrêté a l'axe je suis pas assez riche, et le moteur a très peu rouler...je suis retourné chez bafang le moteur a 5 ans et il est comme neuf. ..

Je ne comprends pas le part avec l'axe; l'axe est cassé aussi?
Sorry, my french is leaving me stranded here, and google is no help: 'My cyc photon LCD and controller are dead, twisted axle I stopped at the axle I'm not sufficiently rich, and the motor ran very badly...I have returned to Bafang the motor has 5 years and it is like new...'
What is going on with the axle? And the other things just broke one day?

 

[branchat]

je me suis rendu compte que l'axe était tordu, quand j'ai changé le contrôleur... Se moteur n'est pas fiable pour mon utilisation..
Distance en vélo, : cyclo photon 1000 miles
Bafang bbshd 7000 miles

 

[raylo32]

Not quite, is correct. More like comparing apples to buffaloes.

I had similar concerns but went with a Grin All Axle V3 on my bike and am very happy with the performance. A kink or two still to work out but no reservations about the rear hub motor.

That said it's a longtail cargo bike, so not quite apples to apples.

 

[nervagon]

So temps are hitting the 90s already in San Gabriel Valley at the beginning of summer. The Photon was not a good choice. It simply cannot handle this heat. At this rate we will be in the hundreds soon.

I will be able to do the 10% grade hot weather test for potential Photon buyers, but my honest feedback will be met with more accusations that I am doing it wrong, not pedaling at a high enough cadence, or have a defective unit… or that long 10% climbs are outside of the scope of intended use for this product.

In 75F degrees, and limited to 700W, the photon down-throttled to just under 500W when climbing. In 90F+ degrees, the motor will probably need to be limited to about 450W, being optimistic. At that point, it is easily outshined by a cheap ToSeven DM02.

My solution for keeping the Photon happy… adding a Bikee Lightest motor to the drive train likely won’t be permanent. I am dropping the chain off-road. That is not the fault of the photon, or the Bikee… it’s the result of me not figuring out how to fit the needed lower chainring tensioner to ensure enough chain wrap with the Bikee and the photon jumbled together. It was an interesting experiment, and revealed some interesting things.

For instance, I ended up loving 300W from each motor for a combined 600W with high combined torque. So a dependable 750W nominal mid drive with high torque would keep me happy in any situation.

As I mentioned before, the thing I hate the most about the Photon is how the thermal regulation bounces the power level all over the place while you are trying to maintain a consistent cadence up a long climb. It is the worst mid drive riding experience ever under those conditions, and honestly just shitty engineering.

I wish I had access to a Brose mid drive bike to compare against the Photon in real world stress. From what I’ve read, the Brose drives are very quiet, and have good torque. I hate the noise that the Bosch performance line motors make, so I would never be happy shelling out for a Bosch drive train bike.

Right now, the specialized Vado and Ride1up prodigy 2 are affordable class 3 Brose drivetrain hard tails with front suspension that can be set up as capable gravel/commuters and I wonder how they would feel compared to the photon in the real world. But I would have difficulty pulling the trigger on a proprietary ebike that has no repair ability.

So yeah, I am torn. I like tinkering on my bikes myself, hate the douchebags at local bike shops, but I feel like the DIY ebike parts scene already peaked and is in either stagnation or full blown decline.

What was the peak? The BBSHD its prime. Companies like Lekkie were designing premium parts for it, and innovative batteries like the potted and individually fused and wireless Luna Wolfpack made the DIY scene vibrant and poised to outshine premium big brand factory ebikes.

Then Bafang turned its back on the DIY scene, Luna discontinued the Wolf Pack and shifted to pushing surrons, and Lekkie never supported another DIY motor again. The promise of Americans converting millions of existing bikes to premium ebikes was now a pipe dream. Destined to remain a fringe hobby. One of the hurdles: Americans are lazy, lack creativity, and basic mechanical skills. It’s the same reason consumer 3D printers failed.

And now that we have ebike prices jumping by up to 25% due to the long-paused tariffs on Chinese ebike components being reactivated… DIY could soar once again if production of modular drive train components shifted to North America. But that won’t happen… because the future isn’t the Jetsons, or Star Trek, etc… it’s dystopian… the enshittification of every promising technology.

Back to the word modular. The electric drive train on bicycles should be modular just like the rest of the components on the bike. We need to ditch the welded-on bottom bracket entirely in favor of an open source 3 bolt pattern that will allow any motor or bottom bracket to be attached to the bike frame. This is so obvious that it really is disappointing that it never came to be.

And back to the tariffs… they aren't new. They were simply paused. And yet all these companies are acting like they were blindsided by this. They were given ample time to prepare, but capitalism only cares about next quarter’s report. The long game isn’t compatible with the wall street casino. And the Wall Street casino shits the bed any time interest rates go above zero.

Damn, that turned into a wondering rant.

 

[Epithemeus]

I wonder how fluid resistant this bearing on the photon stator is? (This is a pic with the rotor taken off of the main shaft showing the section of the main shaft where the rotor attaches on)
If one could be sure no fluid would get through it then this motor could in theory really benefit from some sort of fluid bath. None of the hall sensors or even the copper coils are exposed they are all potted. Then there is a rubber gasket sealing the chamber. That bearing is the only part I could see causing problems, if it gets through that it would eventually migrate its way through the whole gearing system and the chamber the controller slots into (the controller is nicely potted at least). Though to be honest I don't even know enough to say if there would be issues if it did get through. I assume it would eventually wash away the grease? Would love to hear what the more experienced people think about the possibilities here. I've read through some of the threads on cooling geared hubs and that's the full extent of my knowledge.

 

[Gruesome]

So temps are hitting the 90s already in San Gabriel Valley at the beginning of summer. The Photon was not a good choice. It simply cannot handle this heat. At this rate we will be in the hundreds soon.

I will be able to do the 10% grade hot weather test for potential Photon buyers, but my honest feedback will be met with more accusations that I am doing it wrong, not pedaling at a high enough cadence, or have a defective unit… or that long 10% climbs are outside of the scope of intended use for this product.

In 75F degrees, and limited to 700W, the photon down-throttled to just under 500W when climbing. In 90F+ degrees, the motor will probably need to be limited to about 450W, being optimistic. At that point, it is easily outshined by a cheap ToSeven DM02.
[...]

Hey, is yours the San Gabriel Valley near LA, just up Rt.39? I was joking with my bike buddies that we shouldn't get too close to Pasadena on our rides, as they are already part of the heat wave... So it did get hot up there, eh? I thought it was already noticeably hotter in Whittier on one of our rides (which is on the San Gabriel as well, but a bit further towards the coast). Since you mentioned the (or a) San Gabriel, one thing I was wondering is how much motor does it take to make it up Rt.39 into the mountains, say, to Crystal Lake at 5500'? Can the Photon go slow enough to do that? It's like 15 miles with a 6% grade, or thereabouts.

Regarding heat management, you might need something like what these polish guys are making for the TSDZ2: TSDZ2/TSDZ2B motor cooling improvement kit - premium
I thought (and still would like to think) that the built-in temperature management is one of the strong points of the Photon. For the TSDZ2 you even have to retrofit the temperature sensor, otherwise the motor will just happily self-incinerate (or rather, demagnetize), I believe.

I'm still interested in adding a motor, and following this thread, but as I mentioned the Photon (or any other mid motor) Q factor is just unpalatable for me at least for now, and for now I switched to a waxed chain and added aerobars, to hopefully maybe gain a few percent. Thinking about a hub motor.

 

[nervagon]

Hey, is yours the San Gabriel Valley near LA, just up Rt.39? I was joking with my bike buddies that we shouldn't get too close to Pasadena on our rides, as they are already part of the heat wave...

San Gabriel Valley officially runs from around Pasadena at the west end to Claremont at the east end. It's huge. And I am towards the east end between Covina and Pomona. It is very hot already.

I wouldn't ride up the 39 to crystal lake in this weather with the Photon. That would be asking for trouble. But I don't know what the weather is like up there at the top ATM. The bafang BBS drives, no problem. I've ridden the BBSHD in 100F.

At my house, 91F yesterday, 90F today. This will probably be the hottest year on record and we are just getting started into summer.

We are going to need global-warming-resilient-motors. I do know from experience that the BBSHD is one such motor... and I hate that more and more I am feeling like that 9 year old design w/o torque sensing is the only truly dependable mid drive.

Edit: it looks like once you get up to 5500 to 5700 elevation the weather will be nice... in the 70s. Head up in the morning and you'll be fine.

 

[Gruesome]

Totally off-topic...
Got it: the San Gabriel Valley is named after the San Gabriel Mountains (aka Sierra Madre), along whose southern edge it runs east-west, and not for the San Gabriel River (along which I ride a lot). Rather, the valley runs perpendicular to the San Gabriel River, which runs from the mountains along Rt.39 past Azusa and through the Whittier Narrows to the Pacific at Seal Beach. I'm a recent transplant, still getting my bearings.

It's a real bummer that this area is now also getting too hot to make it without A/C through the summer. I think the moderate ('mediterranean') climate was what attracted people here originally (that, and bumping into the Pacific, which put a natural stop to the westward movement).

Even more off topic, what we should do is put wind turbines on that ridge stretching south of your valley from East LA past El Monte and Whittier to south of Riverside, and run them as fans using the peak solar power surplus from noon to late afternoon, extending the cool coastal breeze into your neck of the woods. It's half-crazy only: California doesn't know what to do with all that rooftop solar energy during a time that demand is not that high, the electric utilities do not want to buy it, so we might as well use it for (almost) natural air conditioning for the San Gabriel Valley! Actually, I don't know whether you can run wind turbines as blowers, but the forces should be similar, so mechanically it should work.

 

[hindesite]

Regarding heat management, you might need something like what these polish guys are making for the TSDZ2: TSDZ2/TSDZ2B motor cooling improvement kit - premium

I don't think that will reduce temperatures. IME the casing never seems to get really hot. The issue isn't really just dissipating heat from the casing, it is just that the only non convective path for heat from the outrunner stator is through the baseplate at one end, all the other heat has to be transferred through the air around the stator and rotor. There might be opportunities to increase airflow by ventilating the rotor, (maybe with a ventilated end cap for dry conditions), or an expensive heat pipe system. Heat pipes have a proven track record and are used everywhere and particularly in compact devices. From solar water heating to phones.

The downside might be operating temperature limits for heat pipes*, and no matter what CYC do somebody will still complain the unit is too expensive, too complicated, or doesn't work at 2kW

*there might also be issues with introducing metallic conducting heat pipes within the magnetic fields in the motor, of course...

Pretty sure CYC anticipated heat was going to be a problem - it is part of using outrunner rotors. That's probably why they added decent temperature monitoring and control.

How about a jerry rigged water misting system to cool the casing...

 

[neptronix]

It's got a small, inefficient stator with a bunch of heatsinking already. More metal won't do much, the motor is already optimized ( it had low optimization potential to begin with )


Since the heat transfer is poor, the one thing that could really improve the thermal path to the case is ferrofluid or some kind of oil.

..but you would be a lot better off getting a bigger mid drive.

 

[Gruesome]

No no, you have to spend a minute to browse through the link. Those polish guys improve the heat path from the motor to the housing with several metal pads/fillers. The external cooling fins are just the final touch. But all this is a lot more difficult (and some of it impossible) for an outrunner.

 

[hindesite]

No no, you have to spend a minute to browse through the link. Those polish guys improve the heat path from the motor to the housing with several metal pads/fillers. The external cooling fins are just the final touch. But all this is a lot more difficult (and some of it impossible) for an outrunner.

The stator on this outrunner Photon is essentially inaccessible. There might be minimal gains to be made with thermal pastes and the like during assembly, but the poor heat flow is the tradeoff that you get for compact size and high torque (for the size).

For my usage, CYC navigated all of these compromises pretty much perfectly, I'm sorry that it doesn't work so well for everyone though.

 

[nervagon]

It's got a small, inefficient stator with a bunch of heatsinking already. More metal won't do much, the motor is already optimized ( it had low optimization potential to begin with )

View attachment 354768
Since the heat transfer is poor, the one thing that could really improve the thermal path to the case is ferrofluid or some kind of oil.

..but you would be a lot better off getting a bigger mid drive.

The fins on the Photon casing are cosmetic. There is no thermal transfer. The exterior never gets hot. They could have made the drive unit even smaller without them.

 

[neptronix]

That's bad

The fins on the Photon casing are cosmetic. There is no thermal transfer. The exterior never gets hot. They could have made the drive unit even smaller without them.

That's awful and reminiscent of the big thermal issues with geared hub motors.
OK - there really is no saving it unless you go the liquid cooling route.

 

[nervagon]

The downside might be operating temperature limits for heat pipes, and no matter what CYC do somebody will still complain the unit is too expensive, too complicated, or doesn't work at 2kW

I think if CYC stops lying, stops calling it a 750W nominal mid drive there might be fewer complaints. They even claim that the drive is most efficient at 700W, but my experience seems to indicate that it's closer to 500W.

 

[nervagon]

That's bad


That's awful and reminiscent of the big thermal issues with geared hub motors.
OK - there really is no saving it unless you go the liquid cooling route.

The only practical solution would be porting it and covering it with a dry bag. At least the heat would have a larger space to escape into.

 

[nervagon]

Totally off-topic...
Got it: the San Gabriel Valley is named after the San Gabriel Mountains (aka Sierra Madre), along whose southern edge it runs east-west, and not for the San Gabriel River (along which I ride a lot). Rather, the valley runs perpendicular to the San Gabriel River, which runs from the mountains along Rt.39 past Azusa and through the Whittier Narrows to the Pacific at Seal Beach. I'm a recent transplant, still getting my bearings.

It's a real bummer that this area is now also getting too hot to make it without A/C through the summer. I think the moderate ('mediterranean') climate was what attracted people here originally (that, and bumping into the Pacific, which put a natural stop to the westward movement).

Even more off topic, what we should do is put wind turbines on that ridge stretching south of your valley from East LA past El Monte and Whittier to south of Riverside, and run them as fans using the peak solar power surplus from noon to late afternoon, extending the cool coastal breeze into your neck of the woods. It's half-crazy only: California doesn't know what to do with all that rooftop solar energy during a time that demand is not that high, the electric utilities do not want to buy it, so we might as well use it for (almost) natural air conditioning for the San Gabriel Valley! Actually, I don't know whether you can run wind turbines as blowers, but the forces should be similar, so mechanically it should work.

Wind turbines extract the kinetic energy from the wind, meaning they actually steal the wind and convert it to power. Also they are designed to spin at 10 to 20 RPM. If you fed the motor with electricity in motor mode, the draft created would be opposite to the direction they are set up in to capture wind. So the turbines would need to be set up to pivot at least 180 degrees on the fly. It's technically possible... but would the energy needed to spin them like a giant fan be more than they capture the rest of the time? Possibly.

 

[Gruesome]

Still completely off topic:
I don't think it matters what (if any) energy the wind turbines produce at other times. I'm suggesting to burn off the excess peak solar power available during the hottest time of the day. I think we are talking about a few GW. Going through the numbers, 1 GW can accelerate 80,000,000 kg (~ same in cubic meters) of air to 5 m/s, about 11 mph, which is a reasonable breeze. So every second that would be a cube 5m deep, and for example 1km high and 16km wide. Spreading 500 2MW turbines 100 feet apart would achieve this power density. Generator turbines might not work, you might need special blowers. Sure, might be expensive, but Southern California is the 13th largest economy in the world; if we can't afford it, who else?
(Obvious problem: birds - unlike generating turbines, which slow the air down very little, these gizmos would couple strongly to the air and anything in it....)

 

[rocketman58]

Hey, is yours the San Gabriel Valley near LA, just up Rt.39? I was joking with my bike buddies that we shouldn't get too close to Pasadena on our rides, as they are already part of the heat wave... So it did get hot up there, eh? I thought it was already noticeably hotter in Whittier on one of our rides (which is on the San Gabriel as well, but a bit further towards the coast). Since you mentioned the (or a) San Gabriel, one thing I was wondering is how much motor does it take to make it up Rt.39 into the mountains, say, to Crystal Lake at 5500'? Can the Photon go slow enough to do that? It's like 15 miles with a 6% grade, or thereabouts.

Regarding heat management, you might need something like what these polish guys are making for the TSDZ2: TSDZ2/TSDZ2B motor cooling improvement kit - premium
I thought (and still would like to think) that the built-in temperature management is one of the strong points of the Photon. For the TSDZ2 you even have to retrofit the temperature sensor, otherwise the motor will just happily self-incinerate (or rather, demagnetize), I believe.

I'm still interested in adding a motor, and following this thread, but as I mentioned the Photon (or any other mid motor) Q factor is just unpalatable for me at least for now, and for now I switched to a waxed chain and added aerobars, to hopefully maybe gain a few percent. Thinking about a hub motor.

I'm in the Whittier area and sometimes do climbs like Turnbull Canyon. Right now I have a geared hub drive on my 20" wheeled trike. I have no issues climbing with the hub drive, especially since it is a standard wind motor in a 20" wheel. But I wanted to go mid drive for other reasons such as torque sensing, and the Photon looks attractive. I'm not too concerned about heat issues as I seldom ride in temps higher than 85 degrees. Even if the motor can handle it, I cannot.

You mentioned Q factor. This has been a big concern for me. Currently I have a Q of 175mm. It seems most or all aftermarket mid drives have a Q of 200mm or more. And typically they have a larger Q offset on the drive side. This offset is even worse for me than the increased Q. With the Photon you can set it up to have equal Q on both sides. What is the lowest Q factor after market mid drive you know of?

PS: I need 152mm cranks so this is another problem.

 

[Zambam]

............... What is the lowest Q factor after market mid drive you know of?

On my Tongsheng TSDZ2 Raleigh Mtn Tour Seneca, 210 mm w stock cranks, 181 mm with Bafang cranks. Whether that's lowest or not I have no idea.