Comparison of Mid-Drive Systems: CYC Motor X1 Stealth Gen.3 vs Photon

Why Compare the X1 Stealth and Photon?

At the beginning of 2024, CYC Motor’s offering became clearer, with a more distinct differentiation of kits based on their power and thus their application. The CYC Motor X1 Pro received the version number 4. It’s the oldest drive system offered by CYC Motor. In fact, the company began its journey with conversion kits a few years ago with this system and continues to improve it, implementing the technical solutions developed for it into other models. So, in 2024, the CYC Motor lineup is as follows:

1. X1 Pro Gen.4 – the most powerful system (with a significantly increased difference compared to Stealth), intended for building strong electric bikes—or realistically, in its current form, more like electric mopeds.
2. X1 Stealth Gen.3 – a mid-range system in terms of both history and power, still strong enough to handle even a heavy rider in tough off-road and mountainous conditions, especially for pedal assist, but even on the throttle alone it won’t give up.
3. Photon – the newest and weakest system, yet with many invaluable advantages, designed for building a bike suitable for riding almost anywhere—except hardcore mountain terrain.

We wrote about the intended use of each drive system in a recent article, although that one still referred to the X1 Pro Gen.3, not Gen.4 – article here

Since the Stealth sits between the X1 Pro and Photon, it can be compared to both. But comparing it to the X1 Pro is mostly about noting how the Pro is stronger, bigger, and by how much—because the design concepts are very similar. Meanwhile, the comparison between Stealth and Photon is more interesting due to fundamental construction differences. Understanding these is more helpful when choosing the right electric drive kit for your needs.

Technical Specifications: X1 Stealth Gen.3 vs Photon

On paper, the differences and similarities look like this:

* – In reality, Photon’s peak power can reach up to 1,500 W (adjustable via the CYC Ride Control app), but under such load the motor is prone to higher stress and faster wear.

As we can see, in terms of technical specifications, the key differences lie in power and torque. Other differences are related to technical design, such as the range of compatible chainrings and bottom bracket types — for instance, the Stealth cannot be used on fatbikes with 120 mm BB width.

Construction Differences Between CYC Motor Stealth and Photon

Here the differences are immediately visible. The X1 Stealth, like the X1 Pro, transfers power to the crank using an external chain. This is done to offset the motor from the bottom bracket axis, allowing the motor body to rise along the downtube. The steeper the downtube angle, the higher the motor sits, preserving ground clearance. In other words, the lowest point of the drive is not the motor, but the chainring — just like in a regular bike. On the other hand, Photon is a…

Photon without chainring compared to Stealth with 32T chainring

But let’s be fair — ground clearance is not just about the lowest point when the bike is level. In real terrain, obstacles like rocks, roots, and logs often appear between the wheels. Because of the frame geometry, the largest obstacles pass just behind the front wheel rather than directly under the bottom bracket. Skilled riding allows you to clear objects taller than the “flat” ground clearance would suggest. While the motor might not lower ground clearance on paper, it can enter th…

Differences in Drive Chainrings

Photon uses a single chainring — the one that powers the bike and is specifically designed for Photon. It features proper offset to improve the chain line. As mentioned earlier, four sizes are available: 34T, 38T, 42T, 50T. In contrast, Stealth supports standard narrow-wide BCD104 bike chainrings, and the manufacturer offers two sizes: 32T and 38T. However, the Stealth’s construction includes a dual-chainring setup. The second chainring transfers power from the moto…

Weight Differences Between the Two Drive Systems

Total kit weights:

• Stealth: ~5.1 kg
• Photon: ~4.4 kg

• Stealth: ~4.2 kg
• Photon: ~3.5 kg

Myths and Facts About the Noise of Both Systems

We prepared a dedicated article about noise — available here. It explains what and how we tested, and the conclusions we drew.

The video shows the noise levels of both systems in a “home” environment, without load. In real-world terrain, Photon feels nearly silent — which can’t be said for X1 Stealth, and especially not for X1 Pro. Some YouTube videos suggest Photon is loud. It’s hard to say why — maybe the sound profile is oddly amplified when recorded with cameras or phones. In practice, Photon is barely audible — whether you believe it or not. The sound is subtle and not unpleasant or piercing. I…

Similarities

Components and parts that are identical for both drive systems include:

• axles (two lengths available: for 68–83 mm bottom brackets and BB92; Photon also has a longer axle option for fatbikes)
• Q-factor* (200 mm for BSA 68–83 mm bottom brackets, 220 mm for BB92 pressfit)
• cranks (ISIS type, 165 mm or 175 mm)
• displays (SW102 and DS103 available)
• throttle (thumb by default, but other options like half or full are available — although officially not for Photon)
• mobile app (available for Android and iOS)
• battery support (from 36 V to 52 V)

* – Q-factor remains the same regardless of the width of the BSA bottom bracket shell (68–83 mm) — both Photon and Stealth use the same kit. Appropriate spacers are used depending on width. The resulting Q-factor is always 200 mm. This also affects the axle length, which is 180 mm. For BB92 pressfit, the axle is 200 mm and Q-factor is 220 mm. The same axle is used in fatbikes with a 100 mm BB shell. Fatbikes with 120 mm BBs require an even longer axle (220 mm), supported only by P…

Photon with 34T chainring vs Stealth with 32T, and other size comparisons

Stealth Gen.1, Stealth Gen.3 and Photon – sample builds: MTB, gravel, fatbike