What Size Chain Does My 1987 Honda CR125 Dirt Bike Use?

Shop Dirt Bike Parts for a 1987 Honda CR125 Dirt Bike.

Introduction

Using the correct chain size is essential for the performance, safety, and longevity of your 1987 Honda CR125 dirt bike. The right chain ensures smooth power delivery, reduces wear on your sprockets, and helps prevent unexpected breakdowns on the track or trail. For a high-revving, lightweight motocross machine like the 1987 CR125, matching the chain to the bike's specifications is key to getting the most out of every ride.

What Chain Size Does the 1987 Honda CR125 Use?

The 1987 Honda CR125 typically uses a 520 chain size as its OEM specification. This is the standard for most 125cc motocross bikes from this era, offering a good balance of strength and weight for the CR125's power output. There are no significant regional or trim variations for this model year, but if your bike has been modified or has aftermarket sprockets, it's always wise to double-check. If you're unsure, you can verify the chain size by checking the markings on your current chain or consulting your owner's manual.

Understanding Dirt Bike Chain Sizes

The "520" in a 520 chain refers to two key measurements:
  • Pitch: The distance between the centers of two adjacent pins, measured in eighths of an inch. For a 520 chain, the pitch is 5/8 inch.
  • Width: The internal width between the inner plates, measured in eighths of an inch. For a 520 chain, the width is 2/8 inch (or 1/4 inch).
Many dirt bikes, especially in the 125cc class like your 1987 CR125, use the 520 size because it provides the right mix of durability and low weight for racing and aggressive riding.

How Many Links Does the Chain Have?

The typical OEM chain for a 1987 Honda CR125 comes with 114 links. However, this number can change based on:
  • Switching to larger or smaller sprockets
  • Adjusting the axle position for chain tension
  • Modifying the wheelbase for handling preferences
Always count your current chain's links or measure carefully if you've made any changes to your bike's setup.

Factors That Can Affect Chain Size or Length

Several factors can influence the ideal chain size or length for your 1987 CR125:
  • Riding type: Motocross, trail, or enduro riding may require different gearing and chain lengths.
  • Engine displacement and torque: While the CR125 is a 125cc bike, engine modifications can affect chain requirements.
  • Aftermarket sprockets: Changing sprocket sizes alters the required chain length.
  • Suspension setup: Adjustments to suspension or wheelbase can also impact chain length.

How to Confirm the Correct Chain for Your Bike

To ensure you're using the right chain on your 1987 Honda CR125, follow these steps:
  • Check the side plates of your current chain for stamped size markings (e.g., "520").
  • Count the number of links, including the master link.
  • Reference your owner's manual for OEM specifications.
  • If in doubt, measure the pitch (distance between pins) and width (between inner plates) with a caliper.

When Should You Replace Your Chain?

Replace your chain if you notice:
  • Excessive stretching or kinking
  • Visible rust, corrosion, or stiff links
  • Uneven wear or damaged rollers
It's best practice to replace your chain and sprockets together, as worn sprockets can quickly damage a new chain and vice versa. Riding with a worn or incorrect chain increases the risk of breakage, poor performance, and even safety hazards on the track or trail.

Related Shopping Categories

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Shop Chain Lubricant for a 1987 Honda CR125 Dirt Bike.

Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.