RK Racing Chain M520HD-120 120-Link 520 Series - Heavy-Duty Ride

In this review of the RK Racing Chain M520HD-120, the bottom line is clear: this 520 series chain is aimed at riders who need a heavy-duty, serviceable replacement for street or light off-road bikes up to 400cc. The chain's biggest selling point is build consistency - made in Malaysia from Japanese steel with two-point riveted pins and curled bushings - which delivers dependable tensile strength and a pre-stressed, pre-stretched finish that reduces early adjustment needs. It is recommended for riders who value straightforward durability and conventional clip-style master link serviceability.

Key Features

• Japanese steel construction: Provides a consistent base material for strength and wear resistance compared with unspecified economy chains.
• Two-point riveted pins and curled bushings: Improve joint stability under load so the chain resists failure during normal street and off-road use.
• Pre-stressed and pre-stretched: Reduces the amount of initial adjustment and sag-in during the first few hundred miles.
• Heavy-duty tensile rating: A maximum tensile of 7700 pounds/ft offers a high safety margin for bikes in the stated class.
• Standard 120-link length with clip master link: Easy to install and serviceable with common tools for sprocket and drive-train maintenance.
• Compact dimensions: 15.875mm pin-to-pin center and 19.2 links per ft provide a typical fit for many 520-equipped bikes up to 400cc.

Who It's For

The RK M520HD-120 is best for owners of small to mid-size motorcycles and powersports machines up to about 400cc who want a robust replacement chain that uses proven materials and traditional clip master link service. It's suited to riders who perform their own maintenance and prefer a chain that arrives pre-stretched to minimize break-in adjustments.

Riders who need corrosion-resistant or sealed O-ring performance for very high-mileage touring or wet-climate use should look elsewhere; this non O-ring standard chain prioritizes strength and serviceability over sealed lubrication life. Also consider upgraded sealed chains if minimal maintenance and maximum rust resistance are primary concerns.

Pros & Cons

Pros

• Solid construction from Japanese steel gives a reliable tensile capacity for street and light off-road riding.
• Pre-stressed, pre-stretched finish reduces early adjustments and makes initial fit-up simpler.
• Clip-style master link keeps replacement and field repairs quick and familiar.
• Reasonable weight for the class at about 3.65 lb per 100 links balances durability and rotating mass.

Cons

• Non O-ring design means more frequent lubrication and less protection from rust compared with sealed chains.
• Some users report mixed durability outcomes, including occasional stretch and corrosion if not regularly maintained.

Specifications

Series	520
Links	120 links
Pin-to-pin center	15.875mm
Pin length	18.80mm
Maximum tensile	7700 pounds/ft
Weight	3.65 lb per 100 links
Master link type	Clip

Our Verdict

The RK M520HD-120 is a practical, value-focused heavy-duty 520 chain for riders of up to 400cc machines who prioritize strength, easy servicing, and lower initial maintenance thanks to pre-stretching. It represents good value where sealed O-ring protection is not required, but those in corrosive environments should expect to maintain it regularly to avoid rust and premature stretch.

Frequently Asked Questions

Is this chain suitable for my 400cc motorcycle?
The chain is rated for up to 400cc street and non-auburn off-road use and fits typical 520 drivetrains, so it is suitable for most 400cc bikes that accept a 520 chain.

Does this chain come with an O-ring?
No, the M520HD-120 is a standard non O-ring chain, so expect to re-lubricate more often than for sealed chains.

What type of master link is included?
The chain uses a clip-style master link for installation and field repairs.