CYC PHOTON
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nervagon
1 kW
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- Nov 18, 2020
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Wait... does the Photon really have a 190mm Q-factor? That is the same as my BBSHD with straight cranks. I, personally, would not be bothered by such a wide stance, but I can see why others would be alarmed and turned away by that. They should have shot for 170mm which would be about standard for mountain bikes.
Can the Photon be positioned symmetrically on a 73mm BB? I think I saw in this thread somewhere that it's possible.
Can the Photon be positioned symmetrically on a 73mm BB? I think I saw in this thread somewhere that it's possible.
Photon q factor starts at 200mm for 73mm, and up to 230mm (or 240mm, the documentation is inconsistent) for some of the wider 120mm BBs.
I think the rationale around the q factor is that the drive side q factor is constrained by the gear casing and chainring, and then the left is made wider to centre everything.
Not possible, the offset is -0.6mm
Plenty of documentation on CYC website.
Mongo
100 W
But, AFAIK fairly normal for add-on mid-drive motors. I measured my BBSHD (68-73 version with stock crank arms) at 195mm, and if the bike being electrified has a wide chain stay geometry for mid-fat tire clearance, you'll likely need a wide Q stance. 200mm is admittedly a bit much on a 68mm BB, like this minivelo bike (for which I wish CYC offered a 68mm spindle):
Here's CYC's Photon dimension table:
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Except in the Photon manual, the Q factor is listed as 240mm for BSA120. So possibly some discrepancy there.Here's CYC's Photon dimension table:
It's fine. With narrower Q I find my feet tend to be slightly more outboard on the pedals anyway. For hardcore rock gardens and technical terrain the wider Q might be a problem, but I don't ride much of that and also have shorter cranks anyway.
nervagon
1 kW
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- Nov 18, 2020
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Well, it's probably fine for me too, but I have a very wide frame/bone structure. I'm just shocked to learn that the Photon is worse than a BBSHD. That doesn't seem to align with the target demo for the Photon.
It is worth noting that the ISIS standard itself may be contributing to that. Although it isn't explicitly specified in the standard, the crank thickness at the shaft is about 27mm minimum (18.5mm for the splines and clearance, and 8.5mm for the removal thread), which is 54mm when you add both sides. Other proprietary standards (like SRAM DUB) use much thinner crank ends (20mm) to get the Q factor down. That's a difference of 14mm just there.
Axelwik
1 mW
I really don't notice the wide Q-factor with my Photon. My BB shell is 73mm. Certainly narrower than some of those exercise bikes at the gym.
CYC Photon ride
An example of the Photon in everyday use, on one of my local trails. This is one of the steeper trails in this area, and when you follow the on screen telemetry you can see that even though this was a warm day (mid 20s), and a reasonably difficult climb (low gear, front wheel barely staying on the ground) motor temperature barely reached 60 degrees. The way I use this bike, overheating is just not a problem and I struggle to understand why some people claim that it is.
This trail on Trailforks: https://www.trailforks.com/trails/cameron-ridge/
I am totally impressed with this setup and it is the best ebike I've ridden (includes Bafang, Trek and Merida mid drive bikes). That being said, it isn't without some problems - the left crank repeatedly working loose, for example, and the motor I consider to be noisier than ideal.
At the time of posting, this area is closed due to fire risk. This photo on the same trail in very different weather. Still a nice ride, though
An example of the Photon in everyday use, on one of my local trails. This is one of the steeper trails in this area, and when you follow the on screen telemetry you can see that even though this was a warm day (mid 20s), and a reasonably difficult climb (low gear, front wheel barely staying on the ground) motor temperature barely reached 60 degrees. The way I use this bike, overheating is just not a problem and I struggle to understand why some people claim that it is.
This trail on Trailforks: https://www.trailforks.com/trails/cameron-ridge/
I am totally impressed with this setup and it is the best ebike I've ridden (includes Bafang, Trek and Merida mid drive bikes). That being said, it isn't without some problems - the left crank repeatedly working loose, for example, and the motor I consider to be noisier than ideal.
At the time of posting, this area is closed due to fire risk. This photo on the same trail in very different weather. Still a nice ride, though
Wait until I tell you the whole ebike with battery weighs 21.5...
nervagon
1 kW
- Joined
- Nov 18, 2020
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- 358
I sincerely don't understand this reply.
I'm not disparaging you or New Zealand. I wish I could live there. It's just that it was not what many would consider a warm day, and you live in a very moderate climate:
I have torture tested my BBSHD in 40C weather... now that's a motor that can survive anything. When I see reports of the photon in actually hot weather, I'll be impressed.
Any additional data is appreciated, but I'm not sure this ride dispels overheating concerns. But it is great the only issues you are having is a loose crank arm and slightly more motor noise than desired. Have you tried retaining compound at the splined interface?
raylo32
100 kW
Kg no doubt! Not bad but that isn't what I would call light. My Cannondale Photon conversion is similar. I guess they are light as compared to many of the commercial offerings.
This makes a bit more sense:
Although I live in close to Wellington, our temperatures are generally consistently a few degrees higher, maybe up to 30 degrees max. Same in winter, it barely gets cold here, one of the benefits of being right in the center of the Pacific Ocean. As far as the overheating is concerned, I'll treat it as I do the FUD around the motor hanging too low - usually from people who don't own a Photon and have no intention of getting one. A video of overheating should be easy enough to post here; while I'm sure it happens, I think that it is a bit of a fringe case and not really the way the Photon was intended to be used.
Several people have also had the crank problem, I think it is likely a tolerance problem since Truvativ had similar issues in the 2000s. CYC don't think so. though. I use Loctite on the bolt and have used it on the splines also. It is also necessary to ensure the washer/bolt surface is greased (according to the FAQ at the ISIS site). Doesn't make any difference, the crank still randomly comes loose.
Also the left BB bearing is feeling nasty (at 1200km). Others have also reported this, but at lower mileages. There's too much room for error at installation, but that's a topic for another thread.
I was quite surprised at the weight of my sister's Merida eONE SIXTY, size small. Rode like a tank. Mine isn't particularly light - being a midfat bike with basic spec there is a lot of room for improvement, but I think the Merida was 3-4kg heavier.
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Gdoxta
1 µW
New member from Toronto, Canada. Just built my first ebike. I want to first thank you all for your discussion. It helped me decide to go this route. And now I want to share my initial impressions of the CYC Photon after 33km.
As a road and mountain biker, I opted for CYC for torque sensing pedal assistance. I enjoy cycling and wanted to build a commuter bike to help me with my 54km round trip commute twice a week. I considered the Photon and the Stealth gen 3. I opted for the Photon because I don't think I need the extra power (but I do need the range!).
I'm a bit worried about reliability, but no option fit the bill for me perfectly. So I'm taking my chances!
I also considered the 38t vs 42t chainring. My bike came stock with a 36t chainring, so I opted for the 38t CYC option. This way I didn't have to buy a new chain (apparently you can increase your tooth count by 2 before you have to lengthen your chain).
The install itself was pretty easy. But man, there were no instructions! YouTube saved me. I got the old crank set removed and the CYC Photon motor and chainring installed in about 2 hours. Then it took me about 4 hours to complete my peripheral installs and wire management.
I purchased the brake sensors and headlights. I'm not sure I needed them. The brake sensors were a bit challenging to install because my Shimano MT200 brake levers didn't have an obvious place for the sensors. I figured it out by inverting the sensors in the app. So when I pull my brakes, the magnet comes toward the sensor. I also had to use super glue because there was no option to zip tie the sensor to my lever. It works okay. Oddly I found that with both brake sensors installed, the system only picks up the brake signal when both brakes are engaged. In other words, if I only pull the back brake, the motor does not cut power.
With that said, I don't pedal when braking, so the motor isn't outputting power anyway. I probably didn't need the brake sensors. If I were to do it again, I'd skip the brake sensors and get a 2 channel wire harness (you need the 4 channel one if you get the brake sensors).
I also would not buy the headlights again. They are huge, have bulky handlebar mounts and just don't fit the aesthetic of my bike. Plus I broke one of them. But once I had the headlights in hand I knew I wasn't going to install them. Just too big. I searched for other XT90 compatible headlights, but most require some soldering or engineering to make them work with the CYC system. So I'm just going to use my trusty Bontrager Ion.
I read a lot about chain line issues. I don't know if understand it. But I have no issues changing gears across my 8 speeds.
As I noted above, I want to commute with this bike, so I want something that can maintain 30km/h (I'm optimistic about traffic!). When I used various bike gear calculators, I realized a 38t chainring only reaches 30km/h in my two highest gears (11t and 13t) spinning a decent 85rpm. I'm still considering "upgrading" to the 42t chainring. But I must say, with level 2 pedal assist, I can easily reach 30km/h on my highest 3 gears, and even the 4th gear if I don't mind a crazy cadence. In other words, I don't think I need the 42t chainring to reach my target speed. But I may suffer excess cassette wear if I'm using a few cassette gears more than others.
I am a decent novice cyclist. And this ebike weighs about 50lbs with the battery. I can still ride that without much effort, which gives me comfort in the event I run out of battery juice.
I installed the throttle, but I don't enjoy it. it reminds me of my kids' electric scooters.
I took the bike on some steep hills and it handled it well... on level 3 pedal assist. Level 1 and 2 left me gassed. So, I might have to adjust the pedal assist levels a bit.
This is not like riding a dirt bike. I'm still contributing 100 to 200 watts on each pedal assist level when cycling. I just go a bit faster.
I may circle back here once I get a few commutes under the belt. But that probably won't be until April.
As a road and mountain biker, I opted for CYC for torque sensing pedal assistance. I enjoy cycling and wanted to build a commuter bike to help me with my 54km round trip commute twice a week. I considered the Photon and the Stealth gen 3. I opted for the Photon because I don't think I need the extra power (but I do need the range!).
I'm a bit worried about reliability, but no option fit the bill for me perfectly. So I'm taking my chances!
I also considered the 38t vs 42t chainring. My bike came stock with a 36t chainring, so I opted for the 38t CYC option. This way I didn't have to buy a new chain (apparently you can increase your tooth count by 2 before you have to lengthen your chain).
The install itself was pretty easy. But man, there were no instructions! YouTube saved me. I got the old crank set removed and the CYC Photon motor and chainring installed in about 2 hours. Then it took me about 4 hours to complete my peripheral installs and wire management.
I purchased the brake sensors and headlights. I'm not sure I needed them. The brake sensors were a bit challenging to install because my Shimano MT200 brake levers didn't have an obvious place for the sensors. I figured it out by inverting the sensors in the app. So when I pull my brakes, the magnet comes toward the sensor. I also had to use super glue because there was no option to zip tie the sensor to my lever. It works okay. Oddly I found that with both brake sensors installed, the system only picks up the brake signal when both brakes are engaged. In other words, if I only pull the back brake, the motor does not cut power.
With that said, I don't pedal when braking, so the motor isn't outputting power anyway. I probably didn't need the brake sensors. If I were to do it again, I'd skip the brake sensors and get a 2 channel wire harness (you need the 4 channel one if you get the brake sensors).
I also would not buy the headlights again. They are huge, have bulky handlebar mounts and just don't fit the aesthetic of my bike. Plus I broke one of them. But once I had the headlights in hand I knew I wasn't going to install them. Just too big. I searched for other XT90 compatible headlights, but most require some soldering or engineering to make them work with the CYC system. So I'm just going to use my trusty Bontrager Ion.
I read a lot about chain line issues. I don't know if understand it. But I have no issues changing gears across my 8 speeds.
As I noted above, I want to commute with this bike, so I want something that can maintain 30km/h (I'm optimistic about traffic!). When I used various bike gear calculators, I realized a 38t chainring only reaches 30km/h in my two highest gears (11t and 13t) spinning a decent 85rpm. I'm still considering "upgrading" to the 42t chainring. But I must say, with level 2 pedal assist, I can easily reach 30km/h on my highest 3 gears, and even the 4th gear if I don't mind a crazy cadence. In other words, I don't think I need the 42t chainring to reach my target speed. But I may suffer excess cassette wear if I'm using a few cassette gears more than others.
I am a decent novice cyclist. And this ebike weighs about 50lbs with the battery. I can still ride that without much effort, which gives me comfort in the event I run out of battery juice.
I installed the throttle, but I don't enjoy it. it reminds me of my kids' electric scooters.
I took the bike on some steep hills and it handled it well... on level 3 pedal assist. Level 1 and 2 left me gassed. So, I might have to adjust the pedal assist levels a bit.
This is not like riding a dirt bike. I'm still contributing 100 to 200 watts on each pedal assist level when cycling. I just go a bit faster.
I may circle back here once I get a few commutes under the belt. But that probably won't be until April.
raylo32
100 kW
I like the brake sensors for taking off from quickly stop signs and traffic lights. You can preload the torque sensor with the foot that remains on the pedal whilst holding down the brake so the motor doesn't try to go. Then when you let off the brake you have instant response. Alternatively, the throttle is useful for quick getaways.
As for the chainrings... you will be limited in speed with that 38t... unless you just don't like to go faster or the speed would not be advisable on your route, there is no downside except needing a longer chain. And chains are cheap. I find myself wishing for a 50t. I actually have one of those but haven't tried to fit it yet.
As for the chainrings... you will be limited in speed with that 38t... unless you just don't like to go faster or the speed would not be advisable on your route, there is no downside except needing a longer chain. And chains are cheap. I find myself wishing for a 50t. I actually have one of those but haven't tried to fit it yet.
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What battery are you using?
Like you, I was looking to future-proof and got brake sensors, but decided they really are not necessary IRL and never fitted them (I also have MT200 brakesets, the additional clutter would have looked quite ugly). I think with decent torque sensing you don't need brake or gear sensors. I'll probably change out my 1:4 harness with blanked off connectors for a 1:2 harness, next time I order something from CYC.
I did fit the throttle, and that is really useful for short bursts of power if required (I use mine mostly off road). I never really use the throttle for extended distances, it just eats into battery and range far too much.
I find that even with 34t chainring, I'm usually going far faster than anybody else on ebikes since CYC isn't speed limited but most OTS ebikes are (in NZ we have a power limit of 300W for ebikes but no speed limits, other than the posted limits, of course).
SammySamm
10 µW
53ºC on CYCPLUS Thermometer in August 2019; "Barranco de Fataga" Gran Canaria, with my "Mountain Cycle San Andreas / BBS02"!
I have orderd a Photon for my new "Orange Alpine 6" to climbe the vulcane. I´m sure the way i treat it the Photon will survive .
raylo32
100 kW
There are some reports earlier in this thread. I ride my Photon hard using pedal assist on rolling road rides here in the mid-Atlantic heat (mid to upper 90s F) without overheating. Can't do that on continuous throttle, of course, but strong pedal assist, no problem, at least on road hills less than a mile or so. It might be a problem if I took it up to the Catoctins and tried to ride the 17% grades on Park Central Road (up to Camp David) fast at a high assist. Would likely be heat and speed limited there in those conditions.
Gdoxta
1 µW
I'm using a 52v21ah LG jumbo shark battery from Golden Motors. It's pretty cold in Toronto this time of year, so my range isn't amazing. I did a 20km ride today, with a 1km ascent (Gates Gully for my Torontonians). The battery went from 57.x to 53.x. I was using pedal assist 3 the whole time, maxed at 750 watt. But it was closer to 400 watts assistance generally.
