RK 420 MRU Sealed Chain, 120 Links, Black (BL420MRU-120)

The RK BL420MRU-120 420 MRU chain is a lightweight, low-friction drive chain designed for reliable performance on compact motorcycles and small-displacement applications. Its sealed U-Ring construction helps retain lubrication while limiting the entry of dirt and moisture, making it an excellent replacement chain for Honda® Monkey and Honda® Grom models. The black finish provides a clean, durable appearance suitable for street and recreational riding.
RK MRU chains use proprietary Ultra Thin Seal U-Rings, with a seal thickness of less than half that of many conventional O-ring seals. This design helps reduce friction and rotational resistance while maintaining dependable sealing performance. Compared with comparable non-sealed 420 chains, the BL420MRU-120 is engineered to provide up to four times longer chain life and require fewer chain adjustments, helping simplify routine maintenance.
With 120 links, the RK BL420MRU-120 offers a practical fit for applications using 420-pitch chain and can be cut to length when required for proper installation. Always confirm the motorcycle manufacturer’s chain specifications, sprocket compatibility, and final link count before installation. The chain should be properly lubricated, tensioned, and maintained according to the motorcycle manufacturer’s recommendations for best service life.

Features:

• Brand: RK

• Part Number: BL420MRU-120

• Chain Type: 420 MRU sealed chain

• Link Count: 120 links

• Seal Design: Proprietary Ultra Thin Seal U-Rings

• Performance: Engineered for up to four times longer chain life than comparable non-sealed 420 chains

• Maintenance: Designed to require fewer chain adjustments than comparable non-sealed chains

• Construction: Lightweight, low-friction sealed design

• Finish: Black

• Application: Suitable for Honda® Monkey and Honda® Grom motorcycles

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