RK Racing Chain GB420MXZ120 120-Links Gold MX Chain - Lightweight

In this review the RK Racing Chain GB420MXZ120 is evaluated for riders who need a lightweight, durable replacement chain with a distinct gold finish. The bottom line: this is a solid mini-works racing chain best suited for off-road and small-displacement motocross bikes where a high strength-to-weight ratio matters. The chain's chromoly steel construction, oversized alloy pins and RK's HIT heat treatment combine to deliver reliable chain strength and long wear life for riders demanding a strong, well-fitting drive train component.

Key Features

• Chromoly construction: The chromoly steel body provides a strong, fatigue-resistant backbone for aggressive riding and extended service intervals.
• Oversized alloy pins: Special oversized pins increase shear resistance and reduce the chance of pin failure under heavy load.
• HIT heat treatment: All components undergo RK's Heat Induction Transfer process to improve surface hardness and wear resistance.
• Seamless rollers and bushings: The seamless rollers and bushings offer smoother engagement with sprockets, which helps reduce noise and uneven wear.
• High tensile rating: With a tensile strength of 5000 pounds per ft, the chain is capable of handling demanding loads relative to its class.
• Gold finish: The gold plating gives the chain a distinctive look that many customers compliment for appearance and corrosion resistance.

Who It's For

The GB420MXZ120 is aimed at riders of small to mid-size motocross and off-road motorcycles who want a durable, lightweight chain that fits common applications such as older CRF70F-style bikes and other mini-works platforms. It works well for weekend riders and racers who value a combination of durability and looks.

Riders with heavy street motorcycles or machines requiring larger pitch chains should look elsewhere, as this is a mini-works 420-series chain designed for smaller drive trains and specific sprocket pairings rather than heavyweight touring or large-displacement race machines.

Pros & Cons

Pros

• Strong tensile rating and oversized pins contribute to dependable chain strength under load.
• Chromoly construction and HIT heat treatment enhance wear resistance and longevity.
• Seamless rollers and bushings provide smooth rotation and better sprocket engagement.
• Gold finish improves appearance and can help with corrosion resistance.

Cons

• Designed for smaller motocross or mini-works bikes, so not suitable for larger pitch or heavy street applications.
• Customers should verify link count and fitment carefully; one must ensure the 120-link length matches their bike or be prepared to shorten it.

Specifications

Product name	GB420MXZ120 120-Links Gold MX Chain
Brand	RK Racing Chain
Construction	Chromoly steel with seamless rollers and bushings
Pins	Oversized special alloy pins
Heat treatment	RK HIT (Heat Induction Transfer)
Tensile strength	5000 pounds per ft
Link count	120 links with connecting link

Our Verdict

The RK Racing Chain GB420MXZ120 is a well-engineered mini-works chain that offers strong value for riders of small motocross and off-road bikes. With robust chromoly construction, oversized pins and RK's HIT process, it delivers dependable performance and a standout gold finish. Choose it if you need a reliable, lightweight chain that fits the 420-series applications and want a balance of quality chain and appearance.

Frequently Asked Questions

Will this chain fit my bike?
Check your bike's required chain pitch and recommended link count; this is a 420-series 120-link chain intended for mini-works and similar small-displacement drivetrains.

Is the gold finish purely cosmetic?
The gold plating improves appearance and can provide some corrosion resistance, but the chain's longevity comes primarily from chromoly construction and HIT heat treatment.

Does it come with a connecting link?
Yes, the product includes a connecting link to complete installation and sizing on the bike.