RK GC415HRU-140 Racing Gold Chain - 415 x 140 Links

The RK GC Racing Gold Chain Series GC415HRU is a purpose-built sprint racing chain in 415 pitch, supplied here in a 140 link length with a clip-type master link included.

The GC series is RK's latest generation of the HRU racing chain. Both the inner and outer plates are polished and gold plated, which improves seal durability over the previous GB generation. Compared to that older chain, the GC delivers roughly 15% more strength, two to three times the durability, and about 10% less weight.

At the heart of it is RK's Ultra Thin U-Ring seal — under half the thickness of a conventional O-ring. That lets the chain hold its lubrication like a sealed chain while carrying close to the weight of an unsealed one, so it resists elongation over a race weekend and keeps power going to the rear wheel instead of into friction.

Why a sealed chain is worth it

Non-sealed chains are cheap up front, but the grease gets flung out within a session or two and grit works its way straight into the pins and bushings. From there they stretch fast — most riders are chasing adjustment every weekend and replacing the chain two or three times a season.

The U-ring seals on the HRU keep the factory lubricant where it belongs and keep contamination out, so the chain holds its length instead of growing. We ran one of these for a full season of racing on our own bikes without replacing it — just routine cleaning and lube. Fewer adjustments, less sprocket wear, and one chain instead of a stack of them.

Fitment

This is a 415 pitch chain, and 415 is a conversion. It is intended for race bikes that have already been converted to 415 with matching front and rear sprockets — the narrower pitch is a common race-prep step to cut rotating mass and drivetrain drag. A 415 chain will not run on 420 sprockets, so confirm your sprockets before ordering.

Rated for up to 250cc race / 60 HP applications. At 140 links it suits longer wheelbase and taller gearing setups; count the links on your current chain first. You can size down by removing links, but the chain cannot be lengthened.

Specifications

• Part number: GC415HRU-140
• Pitch: 415
• Links: 140
• Finish: Gold plated inner and outer plates
• Seal: Ultra Thin U-Ring
• Tensile strength: 4,800 lbs
• Rating: Up to 250cc race / 60 HP
• Master link: Clip type, included

Racing use only. RK does not recommend the HRU series for street use.