520 Chain Size Explained: Pitch, Roller Diameter & Compatibility Chart
## 520 Chain Size Explained: Pitch, Roller Diameter & Compatibility Chart
If you ride a mid-displacement motorcycle or a powerful dirt bike, you have likely heard about the **520 chain size**. It is one of the most common motorcycle chain specifications on the market, but what do those numbers actually mean? This guide breaks down the technical details and helps you choose the right chain for your bike.
### What Does 520 Mean?
The “520” designation follows a standard numbering system. The **first digit (5)** represents the chain’s pitch in eighths of an inch. A 5 means the pitch is 5/8 inch, or roughly 15.875 mm. The **last two digits (20)** indicate the roller diameter and inner width. A 520 chain has a 1/4 inch roller diameter, which is smaller and lighter than a 530 chain.
Because of its reduced width and weight, this chain size is a popular choice for **sport bikes**, **dual-sport motorcycles**, and **motocross bikes** where saving grams matters. Understanding these dimensions ensures proper fitment and safe operation.
### Pitch, Roller Diameter & Inner Width
Every motorcycle chain is defined by three key measurements. Let’s look at each one for the 520 size:
– **Pitch:** 5/8 inch (15.875 mm) — the distance between three consecutive pins.
– **Roller Diameter:** 1/4 inch (6.35 mm) — the diameter of the rollers that sit on the sprocket teeth.
– **Inner Width:** 1/4 inch (6.35 mm) — the space between the inner plates that fits over the sprocket.
These dimensions must match your **sprockets** exactly. Using a chain with the wrong pitch or roller diameter will cause rapid wear, noise, and potential drivetrain failure.
### 520 vs 525 vs 530: Compatibility Chart
One of the most common mistakes is mixing up chain sizes. Here is a quick comparison:
| Chain Size | Pitch | Roller Diameter | Inner Width |
|————|——-|—————–|————-|
| 520 | 5/8″ | 1/4″ | 1/4″ |
| 525 | 5/8″ | 5/16″ | 5/16″ |
| 530 | 5/8″ | 3/8″ | 3/8″ |
While the pitch is identical across all three, the **roller diameter and inner width differ**. A 520 chain will not fit sprockets designed for a 525 or 530 chain. Always verify your bike’s OEM specification before purchasing.
### When to Choose a 520 Chain
Upgrading to a 520 chain is common in **racing** and **off-road** applications. The lighter weight reduces rotational mass, improving acceleration and suspension response. However, it also has lower tensile strength than a 530 chain, so it is not ideal for high-torque liter bikes.
For a deeper dive into all motorcycle chain dimensions, check out this detailed guide on 520 chain size. It covers conversion charts and real-world compatibility tips.
### Frequently Asked Questions
**Q: Can I replace a 525 chain with a 520?**
A: Yes, but you must also replace both sprockets. The narrower 520 chain requires matching sprockets.
**Q: How often should I replace a 520 chain?**
A: With proper maintenance, every 15,000–20,000 miles. Off-road use may require replacement sooner.
**Q: Is a 520 chain stronger than a 530?**
A: No. The 530 has a larger roller and wider plates,
