The EBMX X-9000 V3 Race Harness For QS138 Motor is a purpose-built wiring harness for custom builds pairing a QS138 70H or 90H motor with the EBMX X-9000 V3 controller, made by EBMX and sold here at GritShift. It comes pre-pinned for the QS hall sensor and a Light Bee X throttle, runs tunes to 26s and weighs 0.44 lb.
Specs verified October 2026 against the live GritShift product page.
Specifications
| Type | Race wiring harness for custom QS138 builds, harness only |
|---|---|
| Controller | EBMX X-9000 V3, required and sold separately |
| Motors | QS138 70H or QS138 90H |
| Pre-pinned plugs | QS hall sensor plug and Sur Ron Light Bee X throttle input plug |
| Included on the harness | Ignition switch, throttle input plug and hall sensor plug, pre-configured for X9000 V3 setups |
| Tune support | EBMX X-9000 app preset tunes for QS138 70H and 90H motors up to 26s battery configurations |
| Sized for | Most 125, 250 and 450 full-size bike frames that mount the controller in the subframe |
| Wire lengths | May need shortening or extending to suit the build layout |
| Weight | 0.44 lb |
| Not stated on the listing | Harness length, wire gauge, connector part numbers, fuse or breaker provision |
What motors does the EBMX X-9000 V3 QS138 race harness fit?
- QS138 70H motor
- QS138 90H motor
Why use a pre-pinned harness on a QS138 conversion?
A custom conversion normally means pinning every connector by hand and chasing wiring faults afterward. This harness is already pinned for plug-and-play hookup to the QS hall sensor and the Sur Ron Light Bee X throttle, which EBMX says takes the guesswork out of wiring the build. The ignition switch, throttle input plug and hall sensor plug come pre-configured for X9000 V3 controller setups.
What controller and tunes does the harness work with?
The X9000 V3 controller is required and is not part of this harness-only kit. The product page points buyers to the EBMX X9000 V3 Controller Plug N Play Kit for the Light Bee we sell. Once fitted, the harness is compatible with the EBMX X-9000 app preset tunes for QS138 70H and 90H motors in battery configurations up to 26s. We also sell the QS138 70h V3 motor itself.
Will the harness reach on my frame?
EBMX sizes the harness for most 125, 250 and 450 full-size bike frames that carry the controller in the subframe. Because every custom build routes differently, the listing warns that wire lengths may need to be shortened or extended to suit your layout, so plan for some soldering and heat shrink at install. The product photo shows the harness with its connectors and the ignition switch and nothing else; the listing names no fuse or breaker, so protect the circuit per the X9000 V3 installation guide.
Where can I buy the EBMX X-9000 V3 QS138 race harness?
Right here. We sell the EBMX X-9000 V3 Race Harness For QS138 Motor at GritShift, made by EBMX. Browse every EBMX part we carry in our EBMX collection.
