# CYC PHOTON

#### Atak_Snajpera

##### 100 W
At the same time they provide presets which are based on some outdated values.

#### raylo32

##### 100 kW
And we don't even know what values they used. I suppose if we wanted we could make a few measured runs and compare to GPS mileage and do the math. But there is really no point since we can't change anything.

At the same time they provide presets which are based on some outdated values.

#### raylo32

##### 100 kW
LOL... Yes. But their customer base of DIYers are generally more math savvy than the genpop, I suspect. And they could at least have had the SW102 set up to take the circumference and then provided one of those tables like what came with every bike computer for the last 40 years with circumferences for pretty much all the wheel and tire size combinations. Those got you close enough and spared all but the most anal of us from having to do the math or physically measuring our wheels.

Tire_size_chart_ENG_151106.pdf (cateye.com)

They didn't want to confuse the poor widdle bicycle riders with math and stuff. Probably assumed we might have a hard enough time just figuring out what wheel size we had. :/

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#### Atak_Snajpera

##### 100 W
Eggrider display had better firmware in this matter. You could enter precise wheel diameter in mm.

#### hindesite

##### 100 W
Eggrider display had better firmware in this matter. You could enter precise wheel diameter in mm.
Would prefer rolling circumference, much easier to measure.

#### Atak_Snajpera

##### 100 W
Would prefer rolling circumference, much easier to measure.
Simple math
rolling circumference / pi = diameter

#### hindesite

##### 100 W
Simple math
rolling circumference / pi = diameter
Not at all; account for tire inflation and distortion. Far easier to just roll out one rotation and measure that. My 27.5+ tires distort a LOT.

Of course, even easier would be for CYC to upgrade their BT to a BT+GPS soc, which would cost a couple of bucks and removes the need for any of this. It is 2023, after all. And I'm pretty sure the power budget of a CYC system would cope.

#### Atak_Snajpera

##### 100 W
Not at all; account for tire inflation and distortion. Far easier to just roll out one rotation and measure that. My 27.5+ tires distort a LOT.

Of course, even easier would be for CYC to upgrade their BT to a BT+GPS soc, which would cost a couple of bucks and removes the need for any of this. It is 2023, after all. And I'm pretty sure the power budget of a CYC system would cope.
If your measured real rolling circumference is for example 2000 mm then you enter 637 mm in settings. Simple math. IT is the value but divided by 3.14 (PI).

#### raylo32

##### 100 kW
I always found the easiest and most accurate method for me was to use the circumference numbers from the table then run a couple of measured miles to see the % difference. Then adjust the circumference input in the computer by the same %. These days using GPS computers, all this measuring and such has become pretty much unnecessary. Then Photon went back to the future and reminded us.

#### knightrider

##### 1 mW
The noise on the gen 3 stealth doesn`t bother me. The photon is quiet. Not as quiet as bafangs though. So far not had any problems with either unit. 1,000 mi. on photon with mostly on road and some hard off road climbs. The stealth has much more hard work thrown at it. Use it on full sus. bike in the mtns only. Lots of hrs. with only the occasional stick getting in the open front drive sys. Carry a leatherman with me as the thrown chain is a mess when it binds on the chainring and front housing. I don`t think the Photon is going to hang with the Stealth with respect to brute output. This is just my finding with both on the same gear inches and 48 volt batteries. I have never had heat problems with either as I don`t use the throttle only on either motor for very long periods of time. The HD bafangs I have I have used like electric motorcycles with no failures. As far as I am concerned the BBSHD is the toughest of all power plts. Just my findings thru the yrs. Just wish the Bafang units had torque sensing on them.

#### knightrider

##### 1 mW
600 miles here and no problems. Loving torque sensor. Hope it holds up long term or the bbshd is going back on. As mentioned earlier, my only complaint is more drag with no motor assistance vs bbshd.

Amen on the holding up or re-install the HD.

#### knightrider

##### 1 mW
Did reinstall my Photon motor and updated with the new firmware from CYC and done a general reset.

I did put less pression on the retaining ring (Chainring retaining ring).

Results: The Photon motor motor is working OK! No more pulsions from the torque sensor system.

Did 100km without problem.

Hope for 20,000km without problem.
I think the Photon doesn`t like very much side load put on it with the tightening nut and the locking ring. Mine wants to loosen on its on and then the unit smooths out. When I re tighten it I notice a slight bumping feeling when I pedal. It doesn`t want to stay real tight and I`m alright with that as long as it keeps working with no faults. The tie wrap trick holds it up against bottom tube and under power it stays against lower tube buy nature.

#### hindesite

##### 100 W
I think the Photon doesn`t like very much side load put on it with the tightening nut and the locking ring. Mine wants to loosen on its on and then the unit smooths out. When I re tighten it I notice a slight bumping feeling when I pedal. It doesn`t want to stay real tight and I`m alright with that as long as it keeps working with no faults. The tie wrap trick holds it up against bottom tube and under power it stays against lower tube buy nature.
What are you referring to when you mention "tightening nut" and "locking ring"?

If the "locking ring" is the split threaded collar with the hex screw (left side), this should never be tightened. Doing so will destroy the bearings. They'll certainly feel lumpy

Similar for the left crank bolt - there must be clearance between the inside of the crank over the spline, and the spacers and ring between it and the bearing, or tightening will load the bearing and the ISIS spline may not seat properly and work loose.

#### hindesite

##### 100 W
If your measured real rolling circumference is for example 2000 mm then you enter 637 mm in settings. Simple math. IT is the value but divided by 3.14 (PI).
Sure, I get that.

Nothing wrong with measuring the circumference, then doing the calculation, then feeding diameter into the display so it can calculate the circumference. Nothing wrong with that at all...

Anyway, all the old style speedometers I've owned have used circumference directly, none of them have worked from diameter.

#### hindesite

##### 100 W
I always found the easiest and most accurate method for me was to use the circumference numbers from the table then run a couple of measured miles to see the % difference. Then adjust the circumference input in the computer by the same %. These days using GPS computers, all this measuring and such has become pretty much unnecessary. Then Photon went back to the future and reminded us.
True, this is a bit frustrating but really no big deal.

Even the most approximate setting will still be way more accurate than almost every car speedometer. Do modern cars use GPS for this yet, or are there legal requirements that the odometer be physical?

#### knightrider

##### 1 mW
What are you referring to when you mention "tightening nut" and "locking ring"?

If the "locking ring" is the split threaded collar with the hex screw (left side), this should never be tightened. Doing so will destroy the bearings. They'll certainly feel lumpy

Similar for the left crank bolt - there must be clearance between the inside of the crank over the spline, and the spacers and ring between it and the bearing, or tightening will load the bearing and the ISIS spline may not seat properly and work loose.
The lock nut on the left side would be the locking nut I would think. Not the jamb nut with the allen sets. All motors whether bafang or cyc have the locking nut on the left side. The locking ring or split threaded collar as you call it is supposed to be slightly pre loaded against the big nut on the left side. The reason for the hole in the collar for you to slightly turn it up against the nut before you tighten the set screw in place.

#### hindesite

##### 100 W
The lock nut on the left side would be the locking nut I would think. Not the jamb nut with the allen sets. All motors whether bafang or cyc have the locking nut on the left side. The locking ring or split threaded collar as you call it is supposed to be slightly pre loaded against the big nut on the left side. The reason for the hole in the collar for you to slightly turn it up against the nut before you tighten the set screw in place.
OK, the left side CYC refer to as a "Left BB Cup"; this contains one of the spindle bearings. There is a small issue with this where the plastic insert dimensions seem to be incorrect, see
and that may be what you are seeing. The bearing in the video seemed to have been damaged after very low kms.

The other CYC refer to as "Retaining Lock Ring" and while I initially did preload this when I first assembled the motor, I have since backed this right off because the possibility of over-preloading the bearings is too likely (my previous SRAM BB had been incorrectly installed by my LBS and had destroyed a bearing in <500km - even though the spindle relatively spun freely). Mine is barely even finger tight. CYC don't really even give any indication or torque value for that adjusting that ring, they say "tighten by hand". I think the hole is for when undoing that ring if it is tight and not for doing it up. It is also easy to fit too many spacers and prevent the ISIS spline from seating properly - mine came loose, and the same has happened with others.

#### Atak_Snajpera

##### 100 W
True, this is a bit frustrating but really no big deal.

Even the most approximate setting will still be way more accurate than almost every car speedometer. Do modern cars use GPS for this yet, or are there legal requirements that the odometer be physical?
Tesla?

#### Atak_Snajpera

##### 100 W
Torque sensor sensitivity determines minimum force on pedals which is required to activate motor. Lower value means that you have to pedal harder in order to activate motor and Vice versa.

Motor assist factor is just a global power multiplier

#### knightrider

##### 1 mW
OK, the left side CYC refer to as a "Left BB Cup"; this contains one of the spindle bearings. There is a small issue with this where the plastic insert dimensions seem to be incorrect, see
and that may be what you are seeing. The bearing in the video seemed to have been damaged after very low kms.

The other CYC refer to as "Retaining Lock Ring" and while I initially did preload this when I first assembled the motor, I have since backed this right off because the possibility of over-preloading the bearings is too likely (my previous SRAM BB had been incorrectly installed by my LBS and had destroyed a bearing in <500km - even though the spindle relatively spun freely). Mine is barely even finger tight. CYC don't really even give any indication or torque value for that adjusting that ring, they say "tighten by hand". I think the hole is for when undoing that ring if it is tight and not for doing it up. It is also easy to fit too many spacers and prevent the ISIS spline from seating properly - mine came loose, and the same has happened with others.
I will say of the many kits that I have installed. The CYC stuff seems to present more problems. The BBS kits aside from obtaining a good chainline are very simple to deal with and for the most part very trouble free. I just like the torque sensor factor on the CYC that is the only sales point for me. If BBS motors had torque sensing I would not bother with the other stuff. The BBSHD is a work horse with no problems when used with reasonable voltage and wattage controllers. Just my experience. I have the Stealth Gen 3 units on full sys. bikes and they work well also. The Photon is not there yet. Someday maybe.

#### Superb_Raccoon

##### 10 µW
So what's the difference.
From the Fine Manual, page 12:

Pedal Assist Sensor
Enable or disable pedal assist.

Torque Sensor Sensitivity
This value pertains to activating pedal assist when
itʼs completely off. This is the amount of pedal
force required to activate the pedal assist. If this
value is set higher, your pedal assist will engage
with less force and vice versa.

Power Ramp Up Time
The amount of time it takes to reach the desired
input. This is the responsiveness of the motor.

Motor Assist Factor
This value pertains to how hard you need to pedal
to get full power.

Cadence Start
This feature allows for a cadence-free pull away.
i.e., only torque (40N.m.) is required to activate
pedal assist.

The really interesting one to me is the Pedal/Throttle Torque Level. This is a hard cap on the 110Nm Max, which if you want to limit damage to the drivechain from overtorque, this is a great setting to have

#### hindesite

##### 100 W
No. They use a rear axle sensor. You even have to set the tire size if different from standard.

#### latevance

##### 1 mW
Can you guys with a Photon see anything missing from this apart from the spindle and leads? What goes where the 6 holes are?

Just a thought, is it actually one of you guys selling it?

Just like other companies when dealing with claims, doesnt surprise me that CYC is reluctant to send new parts before the old are returned for inspection to see if it is a fair claim, and I dont blame them.

Seems the guy was sent a new motor and display under warranty after a complaint, and now he is selling the old motor as fully working because all he needed was a display.

If it only needs a spindle and lead then do you think this is a good buy? Seriously thinking of it to avoid the waiting times.

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#### hindesite

##### 100 W
Can you guys with a Photon see anything missing from this apart from the spindle and leads? What goes where the 6 holes are?

Just a thought, is it actually one of you guys selling it?

Just like other companies when dealing with claims, doesnt surprise me that CYC is reluctant to send new parts before the old are returned for inspection to see if it is a fair claim, and I dont blame them.

Seems the guy was sent a new motor and display under warranty after a complaint, and now he is selling the old motor as fully working because all he needed was a display.

If it only needs a spindle and lead then do you think this is a good buy? Seriously thinking of it to avoid the waiting times.
Don't forget cranks are missing, too.

If you mean the 6 threaded holes on the motor side of the output gear casing, I think that looks normal.

No way I would touch that. The motor and fittings have been absolutely butchered. I have no idea how anybody could make such a mess of the left bearing cup and chainring retaining ring so thoroughly. Who knows what physical damage due to improper installation will have been caused.

I actually feel bad for CYC having to deal with customers who demonstrate this level of IDGA*.

Edit: it still has faults and the left support plate is missing, as are the spacers and screws. Also missing are the spindle spacers and the locking ring. Looks to me like the plastic collar that should be in the chainring side spindle bearing is missing, I don't think that bearing should be visible. The comments around the BB threads not allowing tightening are also a problem, the motor threads may be beyond repair. The unit looks like it has been flopping around in a sandstorm, you can see how it has been bashing against the downtube.

Overall, it is all pretty horrific.

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#### Mongo

##### 100 W
I'd pass too. The other, U.S.-based used Photon for sale on eBay was likely a better deal, even though the final price was higher.

As far as availability, I think the U.S.-based dealers now have Photon inventory on hand, for immediate shipment. Perhaps in Europe now too?

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