If you already own a CYC Photon and are thinking about upgrading, here’s the short, practical version.

The Big Differences

Photon Gen 1
Older outrunner motor, smaller clutch, harder to service, and limited electronics. Solid when it came out, but now outdated.

Photon Gen 2 (Photon 2)
Completely redesigned inrunner motor, much stronger clutch, better cooling, easier maintenance, and full CAN-bus electronics. Peak power around 2000 W and 135 Nm of torque. Lighter and more street-friendly.

Photon Pro
Same basic platform and fitment as the Gen 2, but with higher power (up to 4000 W peak and 180 Nm). About 1 kg heavier. Built for steep climbs, cargo, and private-land performance.

Both Gen 2 and Pro share the same bottom bracket options, chainring sizes (32T–50T), and battery range (36–72 V).

Electronics Are Not Interchangeable

This is the part most people miss:

• Gen 1 speed sensor does not work on Gen 2 or Photon Pro.
• Gen 1 displays do not work on Gen 2 or Photon Pro.
• The wiring harness is completely different.

Gen 2 and Photon Pro both use CAN-bus. They only support the current SW102T and Intuition displays. You cannot just plug in your old Gen 1 display or sensor.

What You Can Usually Reuse

When moving from Gen 1 (or even between Gen 2 and Pro):

• Chainrings (Gen 2 and Pro share the same sets)
• Many bottom bracket parts and crank arms
• Battery (as long as the voltage is compatible)

What you will almost always need to replace:

• Speed sensor (or the proper adapter)
• Display
• Wiring harness

Quick Advice

If you only need more power and already have a Gen 2 kit, the Photon Pro motor + controller is a strong upgrade — just plan on updating the sensor, display, and harness.

If you’re still on Gen 1, it’s usually cleaner (and less headache) to go straight to a full Gen 2 or Photon Pro kit.

We stock the current Photon Gen 2 and Photon Pro kits, plus the matching displays, sensors, and harnesses.

Have a Gen 1 or Gen 2 kit and want to know exactly what parts you can keep? Send us your current setup and we’ll give you a clear list of what you need.

Main Engineering Differences

Gen 1 → Gen 2 major upgrades

• Completely new inrunner motor with better cooling and efficiency.
• Much larger, stronger sprag clutch (addresses the most common Gen 1 weak point under heavy load or aggressive riding).
• Full CANBUS electronics and wider voltage support (up to 72 V).
• Far easier maintenance — open the drive unit with four bolts; controller, torque sensor, motor module, and first-stage gears are designed to be replaceable separately.
• Expanded and improved chainring system (new spider/retainer design). Some Gen 1 chainrings have backward compatibility notes from CYC, but the mounting system is different.
• Quieter and more refined power delivery.

Photon 2 vs Photon Pro

• Same bottom-bracket options, same chainring sizes (32T–50T sets are sold as “Photon 2 / Photon Pro”), same Intuition display, same Ride Control app, same speed sensor, and same battery compatibility (A-series packs work on both).
• Pro has a redesigned motor and higher-output VTON Gen 2 controller for the extra power and torque.
• Bash guards are different (separate part numbers).
• Torque sensor assemblies are primarily listed for the Photon 2 in catalogs — treat full interchange as unconfirmed without checking your exact units.

Can You Swap Parts? Practical Compatibility Guide

If you have a full Photon Gen 1 kit and want to move to Gen 2 You cannot simply drop a Gen 2 motor/controller into a Gen 1 housing or reuse most internals. Gears, clutch, housing, motor core, and controller are different.
Some shared or similar parts exist (certain torque-sensor mechanical pieces, some crank/BB hardware), and CYC notes partial chainring backward compatibility. In practice, the cleanest and most reliable path is a full Gen 2 kit or buying the matching Gen 2 motor assembly plus the peripherals you need.

If you have a Photon Pro motor + controller only and want to use the rest of a Photon Gen 1 or Gen 2 kit This is the most common upgrade question.

What generally works:

• Chainrings — Yes. CYC sells the 32T–50T sets for both Photon 2 and Photon Pro.
• Speed sensor — Yes (shared).
• Intuition display and Ride Control app — Yes.
• Batteries — Yes (any compatible 36–72 V pack).
• Many BB cups, spindles, and crank arms — Often interchangeable across the Photon family.

What needs caution or confirmation:

• Torque sensor assembly — Primarily catalogued for Photon 2. Mechanical fit may be close, but signal/electronics compatibility is not officially confirmed for the higher-power Pro controller. Check with CYC or your dealer before assuming it works.
• Wiring harness — Gen 2/Pro uses CANBUS and updated connectors. Gen 1 harnesses are different.
• Bash guard / chainring covers — Different part numbers between Photon 2 and Pro.
• Housing and internal mounting — The Pro has a longer/heavier motor assembly, so not every Gen 1 or early Gen 2 peripheral will mate perfectly.

Bottom line on swapping:
You can reuse a useful amount of the peripheral kit (chainrings, display, speed sensor, battery, often cranks/BB hardware) when moving to a Photon Pro motor + controller. You should not assume the torque sensor, full harness, or every cover/guard will transfer without verification. The safest approach is to treat the motor + controller as a matched pair and buy or confirm the matching peripherals for that generation.

Which One Should You Choose?

• Photon Gen 2 (Photon 2) — Best all-rounder for most riders. Lighter, configurable for street-legal use in many places, excellent torque sensing, and plenty of power for trails and commuting.
• Photon Pro — Choose this when you regularly face steep climbs, carry heavy loads/cargo, or ride on private land where the extra 45 Nm and doubled peak power matter. Expect more drivetrain wear at the higher output levels.

Both share the same excellent frame compatibility and natural pedal feel that made the Photon popular in the first place.