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)

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MY26 — What Changed (2026 Model Year)

The MY26 is the largest single-year update in Light Bee X history. The 72V electrical system is not compatible with any MY17–25 component. Parts with part numbers containing Y029E are MY26-specific. Parts with YQ2A/YQ2B/Y029A are earlier generations.

Z1 / Z2 Assembly Bundles

MY26 introduced the Z1/Z2 assembly convention across many sections:

• Z1 = Component + all required fasteners/seals packaged together — order Z1 to get everything needed for that sub-assembly in one SKU.
• Z2 = Larger bundle or E-Mark variant — adds bearings, seals, or bushing to Z1.
• The base part number (e.g. -0000) is the component alone, without fasteners.

Battery & Controller — NOT Cross-Compatible

• MY26 controller: 21100-Y029E-00B0 — 72V/10KW. Not compatible with MY17–25 batteries.
• MY26 battery: 26000-Y029E-0000/0100 — 72V/35Ah. Available in FMT and GW connectors. Not compatible with MY17–25 controllers or chargers.
• MY26 charger: 21700-Y029E-0200 — 84V/10A/840W. Matches the 72V battery only.

Brake System — Completely Redesigned for MY26

• MY26 uses a new shared-caliper DOT hydraulic system. Front and rear now share caliper part 52190-Y029E-0000.
• New brake override switch set added: 52121-Y029E-0000.
• MY26 brake components are listed in two separate sections — Front Brake and Rear Brake — and are not compatible with MY17–25 brake parts.

Main Harness — New 72V Harness for MY26

• MY26 main harness: 24100-Y029E-0100 — wired for 72V system. Not compatible with MY17–25.
• MY26 battery power cable: 24110-Y029E-0000.

New MY26 Components (Not in Any Previous Year)

• T-BOX Telematics (21260-Y031A-0200) — connected module, standard on MY26.
• Dual-Hall Throttle (23910-YQ5A-0000) — improved throttle sensor accuracy.
• 420 O-Ring Chain (13114-Y029E-0000) — replaces standard chain.
• 55T Rear Sprocket (13204-Y029E-0000) — replaces 48T/58T options from prior years.
• Front Side Reflector (22910-Y031B-0000).
• White Frame (41100-Y029E-0000-Y1) — new color for MY26.
• Rear Brake Caliper Bracket (52280-Y029E-0000) — new mounting design.

Sections Now Split by Model Year in v26 Parts Manual

• Electrical — Controller/Battery/Charger: MY17–25 version vs MY26 version.
• Lights/Locks/DC Converter: MY17–25 version vs MY26 version.
• Brake System: MY17–25 single section → MY26 split into separate Front and Rear sections.
• Drive System: New dedicated section in MY26 manual (was merged in Swingarm/Midshaft).
• Main Harness: New dedicated section in MY26 manual.