1. Electrical System — Controller, Battery, Charger, Harness

The most impactful updates are in the electrical system.

Controller

• The MY25 controller (21100-Y029A-0100) is backward compatible but performance is capped at 6 kW on older bikes.
• MY17–24 controllers do not work on MY25.

Battery

• The MY25 battery (26000-Y029A-0000) uses a new single connector GW design and is not compatible with MY17–24 frames, harnesses, or charging systems.
• Older dual port batteries are discontinued. The MY24 single connector battery is still supported but is not compatible with MY25.

Main Harness and Power Cables

• MY25 uses a redesigned main harness and power cable set.
• MY17–24 harnesses and power cables cannot be used in MY25 and vice versa.

Charger

• MY25 charger is an updated 12A model (21700-Y028A-0200) that matches the new battery connector.

Bottom line: The entire electrical system — controller, battery, charger, main harness, and power cables — must match the model generation.

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2. Motor Assembly

• The MY25 motor (11100-YQ2A-0401) is a revised 4 kW / 6 kW peak unit. It is mechanically compatible with older models but will only reach full output when paired with the MY25 controller and battery.
• MY17–24 motors can be mounted to MY25 but are not recommended as an upgrade path.

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3. Primary Drive System — Belt, Pulley, Midshaft

• The MY25 primary pulley (13202-YQ2A-0500) and MY25 belt (13111-YQ2A-0500) must be used together.
• MY17–24 Continental and Gates belts and pulleys do not interchange with MY25 parts.
• Midshaft assemblies are shared but pulley and belt pairing must stay within the same model year group.

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4. Braking System

• MY25 moves to DOT-only brake systems and is not cross-compatible unless the entire brake system is swapped as a complete unit.
• Individual MY25 brake components — calipers, master cylinders, hoses — should not be installed on MY17–24 bikes individually.

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5. Wheels and Tires

• Front wheel components are fully compatible across all model years.
• MY25 switches to an 18" rear wheel. MY17–24 use a 19" rear wheel. Rear wheels, tubes, and rim bands are generation specific. Most bearings and bushings are shared.

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Cross-Compatible Components (All Years)

A large portion of the Light Bee platform is shared across all model years:

• Frame and subframe (color differences only)
• Seat, swingarm, linkage system
• Rear shock (MY25 shock fits older models)
• Front fork assemblies — KKE, FastAce, RST, and DNM have their own parts
• Handlebars, stem, and clamps
• Footpegs and side stand assemblies
• Fender sets
• Primary and secondary chains and rear sprockets
• Lighting system — headlight, dashboard, horn, switches, DC converter
• Most body plastics (MY25 number plate fits older bikes with correct MY25 hardware)