Chain Size Guide for Dirt Bikes

Chain Size Guide For Dirt Bikes

Choosing the right chain for your dirt bike shouldn’t be guesswork. Our Chain Size Guide for Dirt Bikes breaks down exactly what you need to know so you always get the right size the first time.

Whether you’re dialing in your kid’s 50cc race bike or swapping chains on your full-size 450, this quick guide covers it all.

👉 Shop all dirt bike chains – 420, 428 & 520 sizes in stock and ready to ship.

What Do Chain Sizes Mean?

Dirt bike chain sizes are based on standardized measurements. The numbers (like 420, 428, 520) refer to the pitch and width of the chain links.

• The first digit refers to the pitch (distance between pins), measured in eighths of an inch.

• The last two digits refer to the internal width of the chain.

Most Common Dirt Bike Chain Sizes

Here’s a no-BS breakdown of the chain sizes used on nearly all dirt bikes:

👉 Quick tip: If your bike is 50cc, you’ll almost always need a 420 chain. If it's a midsize bike like an 85cc, you'll want a 428 chain. And if you’re riding full-size MX, trail, or enduro bikes? Go with a 520 chain—it’s the gold standard.

How to Tell Which Chain Size You Need

1. Check your owner’s manual – It’ll list the recommended size.

2. Inspect your current chain – The size is usually stamped on the links.

3. Look at your sprockets – If you're upgrading sprockets too, make sure they match your chain size.

🔗 Need a New Chain?

We’ve got you covered. Shop chains that match every common dirt bike setup:

👉 Shop 420 Dirt Bike Chains
👉 Shop 428 Chains
👉 Shop 520 Chains

Each one’s ready to ship and built for serious abuse.

Final Thoughts: Chain Size = Less Guesswork

Use this Chain Size Guide for Dirt Bikes to get it right every time. Choosing the right chain helps your drivetrain last longer and your bike run smoother. Whether you’re racing, trail riding, or just ripping around the yard—having the right chain is key.

And if you're ever unsure, hit us up—we actually ride, and we're stoked to help.