## **520 Chain Dimensions: The Complete Guide to Pitch, Roller Width & Sprocket Compatibility**

If you ride a mid-size motorcycle, you have likely encountered the **520 chain dimensions**. Understanding these measurements is critical for safe power transfer, predictable wear, and confident maintenance. This guide breaks down the three core numbers—**pitch, roller width, and sprocket fit**—so you can order and install the correct drivetrain parts the first time.

### **What the “520” Code Actually Means**

The **520 chain dimensions** number is not random. The first digit “5” represents the **pitch** in eighths of an inch. The second and third digits “20” represent the **roller width** in eighths of an inch. So, a 520 chain has a pitch of 5/8 inch (15.875 mm) and an inner roller width of 1/4 inch (6.35 mm). These two figures define how the chain sits on the sprocket and how efficiently it transmits torque.

### **Pitch Breakdown**

**Pitch** is the distance between adjacent pin centers. For a 520 chain, that distance is exactly 5/8 inch. Pitch must match the sprocket tooth spacing precisely. If the pitch is too long, the chain will climb the teeth and accelerate wear. If it is too short, it will bind and crack the sprocket. Always verify that your front and rear sprockets are cut for 5/8-inch pitch.

### **Roller Width & Inner Width**

**Roller width** is often confused with **inner width**. Roller width measures the outer diameter of the roller, while inner width measures the space between the inner plates. For 520 chains, the inner width is 1/4 inch. This dimension determines how the chain fits over the sprocket teeth. A 520 chain will not fit a 530 sprocket because the inner width is too narrow. Conversely, a 530 chain is too wide for a 520 sprocket.

### **Roller Diameter & Pin Length**

**Roller diameter** for a standard 520 chain is 0.400 inch (10.16 mm), and **pin length** is typically 0.740 inch (18.8 mm). These measurements affect **sprocket compatibility** and **chain clearance**. If your motorcycle has a narrow swingarm or chain guard, an oversized pin could rub. Always check the **maximum pin length** allowed by your bike’s specifications before buying a replacement.

### **Sprocket Compatibility Rules**

A 520 chain only works with **520 sprockets**. The sprocket’s tooth thickness must match the chain’s inner width. Using a 520 chain on a 530 sprocket will cause lateral play and rapid wear. Using a 530 chain on a 520 sprocket will not seat properly and can damage the countershaft. When upgrading or replacing, keep the entire drivetrain—chain and both sprockets—in the same series. For a broader comparison of sizes, refer to this detailed guide on 520 chain dimensions and other chain series.

### **Frequently Asked Questions**

**Is a 520 chain stronger than a 525?** Not necessarily. Strength depends on tensile strength and plate thickness, not just width. A high-quality 520 chain can outperform a cheap 525.

**Can I use a 520 chain on a 530 sprocket?** No. The inner width is different, leading to poor engagement and premature failure.

**How often should I measure chain stretch?** Check every 500 miles. A 520 chain is considered worn when it stretches 1% to 1.5% of its original length