SammySamm
New here
Today the Photon Gen.2 has been introduced by „CYC Photon Owners Official“.
The new motor is an inrunner, torque has rised up to 120Nm. Its slightly larger and heavier.
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CYC PHOTON
- Thread starter pxl666
- Start date
Today the Photon Gen.2 has been introduced by „CYC Photon Owners Official“.
The new motor is an inrunner, torque has rised up to 120Nm. Its slightly larger and heavier.
raylo32
Power poster
Since it is too hot and humid to ride even an e-bike today was maintenance day. I finally swapped out the Photon 42t chainring for the 50t version I bought maybe a year ago. I ride mostly on roads and this bike has 26" wheels so never need the lower couple of gears on my 11-32 cassette and I am spun out in the 11t on any downhill even false flat downhills so I thought I'd try the 50 ring. The chain is really a link or 2 too tight from being able to run on the 32t comfortably which I could remedy easily enough but instead I ordered up an Acera 11-40 cassette and an Acera rear derailleur that can handle that 40t cog. That will make the bike more versatile, in case I get into some steeper gravel hills. I Haven't ridden it yet but soon. I'll test it out with the existing cassette and chain before the new stuff arrives. It was about time for a drivetrain refresh anyway.
Meanwhile
Meanwhile
New here and contemplating a photon build for eMTB riding (vs OTS). I ride some technical trails and I occasionally smack the BB pretty hard on a rock. How will the photon hold up to that kind of abuse? About 2800lbs of rider + bike smacking the motor while riding over a rock?
raylo32
Power poster
If the terrain is like our rock gardens here I don't think it would fare well. The motor casing has decent clearance but still sits well below the BB, which is true for all one-piece mid drive motors. I know my dual susp MTB will compress a lot climbing over a pile of these rocks and a low hanging mid drive like Photon might take a hit. For straight eMTB you'd do better with a Stealth or X1. The motors tuck up higher along the down tube... or on some bikes can even be installed within the triangle, IIRC. They come with a pretty much standard looking separate torque sensing bottom bracket. For trails with smaller or no rocks the Photon would work great.
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Thanks. For me, it's pretty much guaranteed that I'm going to smack that motor sooner or later. I already smack my BB enough to know that. The question for me then is just how much of a hit can the motor take? Even if I were to go with a Stealth or X1, I'd still end up smacking them eventually. FWIW, this is almost always while climbing or doing technical traverses. I'm more careful when descending because I'm too old to keep breaking myself.
raylo32
Power poster
On my old Stumpy the X1 motor swings up under the down tube. No way to smack it on anything. Stealth would be similar. You'll still hit the chainrings once in awhile, but those are exactly same position as stock and not attached to the motor. IOW, the motor is safe. I don't worry about it too much now, anyway because I have retired from doing trails that punishing. Photon would work for me where I ride now.
Spragg Clutch issues?
Hi, have many people here had Spragg clutch issues on the Photon? CYC make a big deal about the fact that they upgraded the clutch from 12x20 to 20x28, tripling the torque rating for the Photon Gen 2.
Can anyone confirm for example that their clutch needed replacement due to failure during use (rather than being defective OOTB)? If I'm re-greasing the motor at 3,000km, should I replace the clutch as a matter of course? Mine seems fine ATM.
Does anyone have photos or a spec for the clutch - is it a standard OTS part like most bearings, is it sealed (or should the replacement be sealed) and does it have keyways? Any markings?
Hi, have many people here had Spragg clutch issues on the Photon? CYC make a big deal about the fact that they upgraded the clutch from 12x20 to 20x28, tripling the torque rating for the Photon Gen 2.
Can anyone confirm for example that their clutch needed replacement due to failure during use (rather than being defective OOTB)? If I'm re-greasing the motor at 3,000km, should I replace the clutch as a matter of course? Mine seems fine ATM.
Does anyone have photos or a spec for the clutch - is it a standard OTS part like most bearings, is it sealed (or should the replacement be sealed) and does it have keyways? Any markings?
linklemming
New-ish here
- Joined
- Aug 25, 2011
- Messages
- 43
I had a sprag clutch fail at about 1500 miles. Note that I have always run my Photon in unrestricted race mode so pretty hard usage although I always monitored temps and kept them at or below 90C Supposedly a firmware update made the startup softer so that might make it better.
I only had my unit about a year and it was under warranty, electrify bike was willing to fix it under warranty including free shipping but I just got the parts from CYC in japan. Pretty cheap and easy to do. You can find links to the sprag clutch on the CYC Photon users group on facebook.
Good videos on youtube on disassembly by CYC and johhny nerdout.
Make sure you note the exact orientation of the sprag clutch when removed as it is a one way bearing.
It comes with grease as well
raylo32
Power poster
No problems with sprag clutch here even though I also run unrestricted race mode. Interesting that CYC tout how the Gen 2 will be easier for maintenance when the Gen 1 really is pretty good that way already. I guess pulling that glued on cover on Gen 1 to swap the controller could be a bit of a PITA but the sprag and torque sensor are right there after you pull the chainring.
linklemming
New-ish here
- Joined
- Aug 25, 2011
- Messages
- 43
There are actually two sprag clutches.
I replaced the primary (very small one), around 11:30 in the following video
Attachments
Thanks, I run mine very conservatively generally at low assist but up to about 750W on steep climbs in low gear, never really gets hot. I think my primary clutch will probably last OK but there must be a widespread problem for CYC to address this with the new version. Maybe it is just people running the motor a bit harder.
What actually fails - is there any noticeable wear on the shaft or the gear it fits in, or is it due to damage on the rollers themselves?
I would think this is an area where you really want to make sure everything is greased and moving smoothly so rollers don't engage properly, then overloading the remainder. Maybe preventative maintenance is worthwhile here, dry grease would be a disaster and I guess you won't get any warning.
That's the wrong clutch, but as a matter of interest, the 2nd stage clutch shown in the video is different to the one shown as spare parts on CYC website. Video shows just a caged bearing, the website shows races as well. What does yours look like?
Heh, my old Stumpy is a 2014 EVO
I paid NZ$150
for it because it was derelict and had not been ridden for years - turned it into the best bike I own. That model was the earliest of the modern MTB geometry trends, is lightweight and easy rolling, a delight to ride. Not getting a conversion though, no way, it is just too good for that.linklemming
New-ish here
- Joined
- Aug 25, 2011
- Messages
- 43
I dont remember seeing any 'obvious wear' on parts other than the sprag clutch. Nothing stands out in my memory on the actual sprag clutch either but I am by no means qualified to make any judgements.
But replacing it, fixed the issue and it was pretty cheap.
The initial behavior was that of stuttering on startup from a complete stop. It felt alot like a motor controller which isnt setup right causing the motor to stutter on initial startup. It only happened in the highest assist level and moreso when it was colder. Im guessing this was the sprag clutch slipping. Finally one day it got really bad, I could hear the motor spinning but the motor would not engage. I could get the bike going but it was a crapshoot every time I started or even when applying power after coasting.
Here is a link to the sprag clutch (I replace stage 1)
https://www.cycmotor.com/product-pa...6dlv9cxUgL_Q-TAn5A_aem_sQqcrWgrTTHrZkhrEz2Lhw
raylo32
Power poster
Mine's really old, 2003 XC version, so not much travel. I replaced the fork, the rear shock, and swapped the v-brakes to XT hydros. Luckily the frame has disc mount. Those are still the best bike brakes of any kind I have ever used.
Heh, my old Stumpy is a 2014 EVO
I paid NZ$150
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Thanks, that is really helpful - seems like we should get plenty of warning a=so best to be aware and intervene before any real damage is caused.
raylo32
Power poster
Well, my Photon 50t chainring trial isn't going great. I swapped out the short cage XT rear derailleur with a long cage and popped on the 11-40 cassette... it works and shifts fine except the chain will not stay on the chainring when the rear is shifted to the 40t cog, even on the stand with light pedaling pressure. The chainline is good, or at least as good as it can get. A front chain guide/keeper might work but IDK, and it would be hard to fit one to this big tube Cannondale seat tube. I may have to go back to the 42t chainring and 11-32 cassette that worked flawlessly.... except I could use some higher speed gearing on flats and downhills.
raylo32
Power poster
I am not sure, I didn't look at it too closely since I am not having any problems, but my impression was that it looked like the video, just a bare sprag, whereas the CYC website shows a unit with races and what looks like a seal. But IDK for sure.
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Coming up to 3000km, service considerations?
Just a few km shy of 3000km, 3 years soon too, no motor issues to date, only external stuff like ISIS splines and BB cup bearing failure. In user's experience, should I be considering opening the unit to service/repack it? It is a little noisier than I recall it being but nothing particularly concerning. I worry that I might do more harm than good.
Oh yeah, needed a lift...
Just a few km shy of 3000km, 3 years soon too, no motor issues to date, only external stuff like ISIS splines and BB cup bearing failure. In user's experience, should I be considering opening the unit to service/repack it? It is a little noisier than I recall it being but nothing particularly concerning. I worry that I might do more harm than good.
Oh yeah, needed a lift...
raylo32
Power poster
IDK about whether it is better or not to service but I tend to believe "not". Unless it is leaking out the grease isn't going anywhere. But one thing I do know is that I need to get down there to visit and ride those beautiful trails!
Hi folks,
New member here, but long time diyer. I had BBSHD (1.5k miles), have a bosch longtail cargo (5k miles and going!), and a cyc photon (1k miles and going).
I consider the cyc photon's hardware to be a work of art. Perfect chain line, smooth and quite, and more than enough power IF you peddle. It's also small and light. The HW is so close to a 10/10.
But it's crippled by terrible software. Two firmware updates via their app bricked the controller on two separate occasions. See here for details. Any one else? As many have already noted, the peddle assist settings should be tied to a specific pedal assist level and not global. The bosch motor has 4 levels, and it's clear they change those setting per pedal assist level and its lovely. Those issues plus only 3 levels really cripples what the motor could do.
New member here, but long time diyer. I had BBSHD (1.5k miles), have a bosch longtail cargo (5k miles and going!), and a cyc photon (1k miles and going).
I consider the cyc photon's hardware to be a work of art. Perfect chain line, smooth and quite, and more than enough power IF you peddle. It's also small and light. The HW is so close to a 10/10.
But it's crippled by terrible software. Two firmware updates via their app bricked the controller on two separate occasions. See here for details. Any one else? As many have already noted, the peddle assist settings should be tied to a specific pedal assist level and not global. The bosch motor has 4 levels, and it's clear they change those setting per pedal assist level and its lovely. Those issues plus only 3 levels really cripples what the motor could do.
Photon failing at 3000km :-(
CYC Photon motor from one of the earliest production runs with 3000km use over just under 3 years is becoming noisy and exhibiting a very concerning issue. Bike rides and performs normally at this stage. I would probably not have noticed the wear without inspecting the motor with the chain removed. Motor hasn't been subjected to extended high power use and has generally been used in good weather.
The drag between crank and chainring varies depending on the crank position relative to the motor. This can be felt when operating the chainring by hand, but becomes very obvious when under throttle power. The motor has done this from new, but was barely perceptible initially. It was generally not noticeable in normal use, but is now becoming more evident, and also noisy.
With the chain removed and rotating the chainring by hand, the bearing sounds and feels noisy. I suspect there is an underlying manufacturing problem that was not identified before shipping that has caused this failure over time.
Appreciate any similar experiences from others here, or who have replaced the output spragg clutch.
*I mis-spoke in the video: the chainring of course rotates relative to the crank, but only under throttle power, I was referring to rotating it by hand which is of course a scenario that never occurs in use due to the rear wheel freewheel. When riding without throttle the chainring and crank relationship doesn't change.
I've added another video with no commentary, the mic here is a DJI Mic Mini placed on the bike frame to more accurately record the motor noise. IRL the motor is not this loud.
CYC Photon motor from one of the earliest production runs with 3000km use over just under 3 years is becoming noisy and exhibiting a very concerning issue. Bike rides and performs normally at this stage. I would probably not have noticed the wear without inspecting the motor with the chain removed. Motor hasn't been subjected to extended high power use and has generally been used in good weather.
The drag between crank and chainring varies depending on the crank position relative to the motor. This can be felt when operating the chainring by hand, but becomes very obvious when under throttle power. The motor has done this from new, but was barely perceptible initially. It was generally not noticeable in normal use, but is now becoming more evident, and also noisy.
With the chain removed and rotating the chainring by hand, the bearing sounds and feels noisy. I suspect there is an underlying manufacturing problem that was not identified before shipping that has caused this failure over time.
Appreciate any similar experiences from others here, or who have replaced the output spragg clutch.
*I mis-spoke in the video: the chainring of course rotates relative to the crank, but only under throttle power, I was referring to rotating it by hand which is of course a scenario that never occurs in use due to the rear wheel freewheel. When riding without throttle the chainring and crank relationship doesn't change.
I've added another video with no commentary, the mic here is a DJI Mic Mini placed on the bike frame to more accurately record the motor noise. IRL the motor is not this loud.
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Some progress since my previous post. Spragg clutch seems fine - well greased and clean, no sign of any contamination.
Removing the chainring was a nightmare - had to use the CYC tool, held firmly in place with a 12mm coachbolt and spacers through the BB. Then soaked the ring with CRC for a few hours, and used 2x 1m lengths of 2" and 1" water pipe to extend the leverage on the tools. I was surprised the CYC tool didn't fail. I had more trouble with the chain whip folding.
The larger output bearing appears to be the problem - it seems dry and noisy but apart from minimal dirt on the seal doesn't seem particularly contaminated. What is the size of the bearing (is it 6816-2rs?) and how is it removed and replaced?
I get (as close as I can measure) 80mm x 100mm but can't measure the width with the bearing in place.
Can the output gear and bearing be pulled out using the chainring retaining ring? I've removed the bearing retaining ring, but nothing seems to want to come out.
Any help here?
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Further update after disassembling the motor. Generally the motor is clean inside, no sign of water ingress, with plenty of grease but I would still recommend cleaning and repacking at this mileage. CYC have used a very nice waxy white grease which is brilliant - because it shows any wear and metal contamination very clearly. I would consider there to be normal amounts of metal contamination on the gears at this stage.
However there seems to be 2 problems, one the has existed since manufacture, and the other during use.
1: The crank bearing in the centre of the chainring retaining ring is not concentric with the axis through that side of the motor. This introduces variable drag as shown in the previous videos. I don't have a dial gauge to measure this, but it is bad enough that I could probably measure it with digital calipers. :-(
See this video:
2: The large bearing that mounts the output gear is stuffed. This is a 6816-2RS bearing, and shows signs of water damage. This is a bearing that is very exposed to the environment and in a particularly dirty location. The rubber shields are not enough to protect the bearing - there is a large retaining ring (use a pin spanner to remove, is reverse threaded) that protects the outer edge of the seal, but the inner edge of the seal on the outside of the bearing is located under the clearance gap between the retaining ring and the chainring and there is no extra protection. Even a thin plastic shield may have made a difference, but surely there is a way to fit an o-ring or proper seal in there?
I cleaned out and flushed the bearing and repacked it, and it will run a little while longer, but it is irreparably damaged and needs replacement. The old bearing needs to be pressed off the gear, has anybody done this? How tight is it?
Video:
