GOOFIT
Transmission Gearbox Spindle for 50cc 110cc 125cc GY6 & YX Engine Pit Dirt Bike
Transmission Gearbox Spindle for 50cc 110cc 125cc GY6 & YX Engine Pit Dirt Bike
5.0 / 5.0
(2) 2 total reviews
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Product Overview
Restore the smooth shifting and power delivery of your drivetrain with this High-Performance Transmission Gearbox Spindle. Engineered for small-displacement engines ranging from 50cc to 125cc, this spindle is a critical internal component that manages gear synchronization. Whether you are repairing a 4-stroke GY6 scooter or a YX-powered pit bike, this spindle provides the precision needed for accurate gear meshing. By reducing mechanical noise and resisting wear, it ensures your transmission operates reliably under the high-stress conditions of off-road riding.
Product Compatibility
| Component Type | Specification |
| Engine Types | GY6, YX, TCMOTOR (4-Stroke) |
| Displacement | 50cc, 70cc, 90cc, 110cc, 125cc |
| Vehicle Types | Pit Dirt Bikes, Scooters, Motorcycles, Mini-Bikes |
| Common Brands | TaoTao, Apollo, SSR, Thumpstar, Lifan |
| System | Manual or Automatic Gearbox Assemblies |
Specifications
| Feature | Details |
| Part Type | Gearbox Main/Counter Spindle |
| Material | Hardened High-Grade Carbon Steel |
| Surface Finish | Precision Ground & Wear-Resistant Coating |
| Installation | Direct OEM Replacement |
| Package Includes | 1 x Transmission Gearbox Spindle |
Key Features
- Enhanced Durability: Manufactured from high-quality hardened materials to maximize resistance against "pitting" and metal fatigue, significantly extending the service life of your transmission.
- Precision Meshing: Effectively improves gear meshing accuracy, which reduces internal vibration and noise while preventing gears from slipping or "popping out" under load.
- Stable Power Delivery: Ensures a more stable and reliable transfer of torque from the engine to the drive chain, improving the overall riding feel and vehicle control.
- Cost-Efficient Maintenance: Designed for straightforward installation; clear dimensional accuracy allows for a replacement process that saves on professional mechanic labor costs.
- Smooth Operation: The precision-ground surface reduces friction between the gears and the spindle, allowing for smoother shifts and better thermal management inside the gearbox.
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Fitment FAQ
Will this part fit my specific model and year?
This gearbox assembly is intended for 50cc 110cc 125cc GY6 & YX Engine Pit Dirt Bike. Key physical/spec details from the product data include 50cc, 125cc, 70cc. Use the compatibility table and product photos together before ordering.
Do I need to match the OEM part number?
Yes. If your original part has a stamped OEM or manufacturer number, match that number first before ordering. For this gearbox assembly, also compare the chain size, tooth count, shaft diameter, case style, sprocket alignment, and 2-stroke/4-stroke engine type. This is especially important for GY6 GY6 models because similar model names can use different parts by year or trim.
What models or situations does this part not fit?
Do not order this gearbox assembly for machines outside the listed compatibility, or for units with different chain sizes, shaft diameters, tooth counts, sprocket alignment, or case styles. Do not rely only on the model name or engine size.
What should I check before ordering?
Before ordering, compare your original part with the photos and check the chain size, tooth count, shaft diameter, case style, sprocket alignment, and 2-stroke/4-stroke engine type. Recheck listed specs such as 50cc, 125cc, 70cc. If any connector, mounting point, size, or year detail is different, confirm fitment before installation.
As a DIY builder of go karts and custom motorized bikes I was astonished to find this four speed gear set by Goofit for just 25 bucks. While building your own transmission may not be up everybody's alley (requires a basic understanding of how transmissions work as well as some mechanical and welding skills to build the transmission case and shifter mechanism) this gear set is really all you need (except for four good bearings) for the internal componenets to build a shifter cart or scooter transmission. There are some very helpful videos on the web (search "diy 4 speed gearbox") to show you the basic steps and the skills/tools required to tackle the project. As shown in the photos, mine is not completed yet but I'm having great fun with it so far and I'm far enough along that I am certain it will function well in the shifter cart I am putting it in. This is the same gearset found on many pit bikes and pocket rockets so it is built to take a good deal of abuse. This is a real bargain for the DIY builder willing to put in the time and effort to build the case and the shifter. I'd give it even more stars if I could.
These are made better then the oem ones on my 2024 syx moto 125cc pit bike. Yes it is a Chinese pit bike so if you have this bike or something close to it with bad transmission gear I highly recommend these