Tag: PAS Sensor Wiring

  • How to Make an Electric Dirt Bike Street Legal: Pedal Kit Installation, PAS Wiring & Class 2 Conversion Guide

    How to Make an Electric Dirt Bike Street Legal: Pedal Kit Installation, PAS Wiring & Class 2 Conversion Guide

    One of the fastest-growing trends in the electric mobility community is converting off-road electric dirt bikes into street-legal Class 2 or Class 3 e-bikes. Adding functional pedals, street-legal lighting, and a controller speed limiter allows riders to enjoy their e-dirt bikes on public streets, suburban neighborhoods, and bike paths without running into law enforcement issues.


    1. Federal & State E-Bike Class Definitions

    To qualify as a street-legal bicycle rather than an unregistered motor vehicle (Moped/Motorcycle), your electric dirt bike must conform to standard e-bike classifications:

    Whether you are modifying a compact platform like a Razor or a heavy-duty frame like a MotoTec, staying compliant starts with knowing your frame’s base setup. Check our Razor MX125 & MX650 Battery Upgrade & Wiring Guide or MotoTec Electric Dirt Bike Troubleshooting Guide to verify your chassis layout.

    E-Bike Designation Top Speed Throttle Requirement Pedals Required?
    Class 1 E-Bike 20 mph No Throttle (Pedal Assist Only) YES (Mandatory)
    Class 2 E-Bike 20 mph Throttle Allowed YES (Mandatory)
    Class 3 E-Bike 28 mph Pedal Assist to 28mph (Throttle capped at 20mph) YES (Mandatory)

    2. Universal Bolt-On Pedal Kit Installation

    Most electric dirt bikes come from the factory with rigid footpegs instead of cranksets. Installing a universal pedal assist conversion kit involves three primary mechanical steps:

    1. Mounting the Bottom Bracket Bracket: Clamp or bolt the bottom bracket mounting plate onto the frame tubing directly below the motor mount.
    2. Chain Drive Setup: Run a secondary #410 or standard bicycle chain from the left/right pedal crank sprocket to a freewheel mounted on the rear axle.
    3. Crank & Pedal Attachment: Torque down 170mm aluminum alloy crank arms and standard 9/16″ street pedals.

    💡 Pro Modder Insight: Look for a pedal kit featuring a one-way freewheel bearing. This prevents the electric motor from spinning your pedals violently when accelerating via hand throttle!

    3. Wiring a PAS (Pedal Assist Sensor) to Your Controller

    A Cadence PAS Sensor uses a magnetic disc attached to the crank spindle to send pulse signals to the speed controller whenever you turn the pedals.

    [PAS SENSOR CABLE] —> 3-Pin SM Connector:
    – RED WIRE —> +5V Sensor Power
    – BLACK WIRE —> GND (Ground)
    – BLUE/YELLOW —> PAS Pulse Signal Input Pin

    When wiring PAS sensors into high-power or aftermarket controllers, consult our comprehensive Sabvoton & Kelly Controller Universal Wiring Breakdown for precise terminal pinouts.

    4. Speed Limiter & Street Mode Toggle Switch Setup

    To ensure full compliance, many riders install a hidden “Street Legal Switch” that toggles the bike between an unrestricted Off-Road Mode and a 20 mph Limited Street Mode.

    How to Wire a Dual-Speed Limit Switch:

    • Locate the 2-pin speed limiter loop on your brushless controller (usually two thin blue or white wires).
    • Cut the loop and wire a handlebar-mounted 2-position rocker switch inline.
    • Switch CLOSED: Controller caps speed at 20 mph / 750W (Class 2 Street Mode).
    • Switch OPEN: Full battery voltage & unrestricted motor power (Off-Road Mode).

    For a clean handlebar controls layout with built-in speed switches and key ignition, see our step-by-step tutorial on Razor Stock Throttle to 3-Speed Key Ignition Wiring Guide.

    5. Essential Street-Legal Accessory Checklist & FAQ

    Q: Do I need a DOT headlight and turn signals to ride on street roads?

    A: For Class 1-3 e-bikes, a white front headlight (visible from 500 ft) and a red rear reflector/tail light are universally required for night riding. Turn signals are recommended but not legally required in most US states for standard e-bikes.

    Q: Will adding a pedal kit pass police inspection if I get stopped?

    A: In almost all jurisdictions, having operable pedals, a 750W rating decal, and a functional 20 mph speed limiter satisfies the statutory definition of an e-bike, preventing impoundment as an unlicensed motorcycle.


    Note: Building your street-legal e-dirt bike on a low budget? Read our guide on How to Restore & Build an Electric Dirt Bike Under $200.

    Disclaimer: E-bike regulations vary by state, county, and municipality. Always check your local Department of Transportation (DOT) guidelines before riding on public roadways.