There can be no doubt about the fact that chain size is extremely important when it comes to the adrenaline-fueled world of BMX, where every millisecond and inch counts because getting it right can make all the difference between a flawless ride and a frustrating experience.
To ensure optimal performance, durability, and rider safety, you must understand the intricacies of chain sizing as a BMX rider, regardless of how long you have been riding the sport. You will always encounter the question what size chain do I need for my BMX bike?
We’ll cover everything you need to know about BMX chain sizing, so you can make an informed decision that will enhance your riding experience.
What Size Chain Do I Need for My BMX Bike?
At the heart of every BMX setup lies the chain – the unsung hero that transfers power from your pedals to the wheels, propelling you forward with each revolution. However, finding the right chain size can be a daunting task, especially for those new to the world of BMX.
The key to unlocking the perfect fit lies in understanding the relationship between your bike’s rear sprocket size, the number of teeth on your chainring, and the overall chain length.
BMX Chain Size Chart
To simplify the process of determining the appropriate chain size, refer to the following BMX chain size chart:
| Rear Sprocket Size (Teeth) | Chainring Size (Teeth) | Chain Length (Links) |
| 16 | 25 | 96 – 100 |
| 17 | 25 | 98 – 102 |
| 18 | 25 | 100 – 104 |
| 19 | 25 | 102 – 106 |
| 20 | 25 | 104 – 108 |
This chart provides a general guideline for matching your rear sprocket and chainring sizes with the corresponding chain length, measured in the number of links. It’s important to note that these recommendations are approximate, and your specific setup may require slight adjustments based on factors such as frame geometry and personal preferences.
BMX Sprocket Sizes:
BMX bikes are renowned for their agility and responsiveness, which is largely attributed to their smaller sprocket sizes compared to other cycling disciplines. The most common rear sprocket sizes range from 16 to 20 teeth, while the chainring size is typically 25 teeth.
Understanding these sprocket sizes is crucial when consulting the BMX chain size chart, as they directly influence the required chain length.
20 Inch BMX Bike Chain
If you’re riding a 20-inch BMX bike, the standard chain length typically falls between 104 and 108 links, assuming a 25-tooth chainring and a 20-tooth rear sprocket.
However, it’s always wise to double-check your specific bike’s measurements and consult the manufacturer’s recommendations or a professional bike mechanic for optimal chain sizing, as variations can occur due to frame geometry and personal preference.
BMX Bikes and Chain Considerations
BMX bikes are designed to withstand the rigors of high-intensity riding, with riders frequently performing tricks, jumps, and stunts that put significant stress on the drivetrain.
As a result, choosing a high-quality, durable chain is essential to ensure reliable performance and longevity.
Popular BMX chain brands like KMC, Shadow Conspiracy, and Odyssey are renowned for their strength and durability, making them ideal choices for BMX enthusiasts. Learn how tight should BMX chain be.
Best BMX Chain:
When selecting the best BMX chain, several factors come into play, including strength, weight, and smooth operation. KMC’s BMX chains, such as the KMC Z510HX, are widely regarded as industry leaders, offering exceptional durability and performance.
These chains feature reinforced side plates and hollow pins, providing strength without compromising weight or pedaling efficiency.
Odyssey’s Blaster and DirectDrive chains are also highly sought after, boasting a unique design that minimizes chain stretch and ensures smooth shifting. Additionally, brands like Shadow Conspiracy and Federal offer high-quality BMX chains tailored for various riding styles and preferences.
Proper Chain Maintenance
While selecting the right chain size is crucial, proper maintenance is equally important to ensure optimal performance and longevity. Regular cleaning and lubrication are essential to prevent premature wear and tear, as well as to minimize the risk of chain snapping or derailment.
Use a high-quality bicycle chain lubricant specifically designed for BMX chains, and apply it sparingly to avoid attracting dirt and grime. Additionally, inspect your chain regularly for signs of wear, such as stretched or damaged links, and replace them as needed to maintain optimal performance and safety.
Frame Geometry and Chain Sizing
What size chain do I need for my BMX bike? When selecting the appropriate chain size, it’s important to consider your bike’s frame geometry. BMX frames can vary in design, with different chainstay lengths and bottom bracket heights, which can impact the required chain length.
Consult your bike manufacturer’s specifications or seek advice from an experienced BMX mechanic to ensure you choose the correct chain size for your specific frame.
Chain Tension and Adjustment
Proper chain tension is essential for smooth pedaling, efficient power transfer, and minimizing wear on your drivetrain components. Too much tension can cause excessive stress on the chain and other components, while too little tension can lead to chain derailment or slippage.
To adjust the chain tension on your BMX bike, follow these steps:
- Shift the rear derailleur to the smallest cog (if applicable).
- Loosen the rear axle nuts or quick-release skewer.
- Adjust the position of the rear wheel by sliding it forward or backward in the dropouts until the desired tension is achieved.
- Re-tighten the axle nuts or quick-release skewer.
- Check the chain tension by pulling it away from the chainstay – it should have about 1/2 inch of vertical play.
Remember, proper chain tension is essential for performance and safety, as a loose or overly tight chain can lead to potential mishaps or injuries.
Chain Compatibility
When replacing your BMX chain, it’s crucial to ensure compatibility with your existing drivetrain components, such as the chainring and rear sprocket.
Most BMX chains are designed to work with standard BMX drivetrains, but it’s always best to consult your manufacturer’s specifications or seek advice from a professional bike mechanic to ensure a seamless and compatible installation.
Specialized BMX Chains
In addition to standard BMX chains, some manufacturers offer specialized chains designed for specific riding styles or applications.
For example, half-link chains are popular among BMX riders who frequently perform grinds or stalls, as they provide a tighter clearance between the chainstay and the chain, reducing the risk of hangups or snags.
Similarly, colored or anodized chains are available for those seeking a personal touch or a unique aesthetic appeal to their BMX setup.
How to Measure Your BMX Chain Size
While consulting the BMX chain size chart and manufacturer recommendations is a good starting point, accurately measuring your existing chain can provide invaluable insights into the perfect chain size for your bike. Here’s a step-by-step guide to measuring your BMX chain size like a pro:
Step 1: Gather Your Tools
Before you begin, make sure you have the following tools on hand:
- A ruler or caliper (for precise measurements)
- A chain wear indicator tool (optional but recommended)
- A clean, well-lit workspace
Step 2: Shift Into the Appropriate Gear
Start by shifting your rear derailleur (if applicable) to the smallest cog to ensure maximum chain slack. This will make the chain easier to work with and provide a more accurate measurement.
Step 3: Count the Links
With the chain slack, carefully count the number of links from one end of the chain to the other. Make sure to include both the inner and outer links in your count. Record this number for reference.
Step 4: Measure the Chain Length
Next, use your ruler or caliper to measure the overall length of the chain from one end to the other. Measure along the inner side of the chain, ensuring it’s taut but not stretched. Record this measurement in inches or centimeters.
Step 5: Check for Chain Wear (Optional)
If you have a chain wear indicator tool, this is an excellent opportunity to check for any signs of excessive wear or stretch. Insert the tool between the chain links, and if it fits snugly, it may be time to replace your chain.
Step 6: Compare Your Measurements
With your chain link count and length measurements in hand, consult your bike manufacturer’s specifications or the BMX chain size chart to determine the appropriate chain size for your setup.
Remember, the chain length should fall within the recommended range for your specific combination of rear sprocket and chainring sizes.
Step 7: Consider Additional Factors
While the measurements provide a solid foundation, it’s essential to consider additional factors that may influence your final chain size decision. These include:
- Frame geometry: Different chainstay lengths and bottom bracket heights may require slight adjustments to the chain length.
- Riding style: If you frequently perform grinds or stalls, a shorter chain may be preferable to prevent snags or hangups.
- Personal preference: Some riders prefer a slightly tighter or looser chain tension based on their riding style and comfort.
By following these step-by-step instructions, you can accurately measure your BMX chain size and make an informed decision that maximizes performance, reliability, and safety on the trails and in the park.
Here you can learn more about the Best BMX bikes for beginners.
Conclusion
Choosing the right chain size for your BMX bike is a crucial step in ensuring optimal performance, safety, and longevity. By understanding the relationship between sprocket sizes, chainring teeth, and chain length, you can confidently select a chain that fits your bike like a glove.
Remember, a properly sized and maintained chain not only enhances your riding experience but also reduces the risk of costly repairs and potential injuries.
Embrace the thrill of BMX riding by equipping your bike with the perfect chain, and get ready to conquer the streets, parks, and trails with unparalleled smoothness and power.
Whether you’re a seasoned BMX rider or just starting, mastering the art of BMX chain sizing will elevate your game and unlock a world of exhilarating adventures on two wheels.
So, what are you waiting for? Gear up, pedal hard, and let your skills soar to new heights with the perfect chain by your side.
FAQs:
Q1: how can I tell what size bike chain I need?
A: To determine the right bike chain size, you need to consider the number of teeth on your rear sprocket and chainring. Consult a BMX chain size chart that matches your sprocket/chainring combination to the recommended chain length in links.
Q2: what BMX chain should I get?
A: When choosing a BMX chain, consider reputable brands like KMC, Shadow Conspiracy, and Odyssey that offer durable and high-performance options. Look for features like reinforced side plates, hollow pins, and anti-stretch designs.
The best chain will depend on your budget, riding style, and personal preferences for weight, strength, and smoothness.
Q3: what is the difference between 18 and 3 32-chain BMX?
A: The 1/8″ and 3/32″ measurements refer to the chain’s inner width or roller diameter. BMX bikes typically use the narrower 1/8″ chains, which are lighter and more compact, suiting the smaller sprockets and tighter clearances.
The slightly wider 3/32″ chains are more common on larger bicycles and can provide increased durability but may not fit properly on BMX drivetrains.
Q4: what size sprocket is best for BMX?
A: The most common rear sprocket sizes for BMX bikes range from 16 to 20 teeth, with 25 teeth being the standard for the chainring.
Smaller sprockets like 16-18 teeth provide higher top-end speed but sacrifice low-end torque, while larger sprockets like 19-20 teeth offer better acceleration and climbing ability. The ideal size depends on your riding style, terrain, and personal preference.
Q5: how do you calculate chain size?
A: To calculate the appropriate chain size, you need to consider the number of teeth on your rear sprocket and chainring. Consult a BMX chain size chart that matches your sprocket/chainring combination to the recommended chain length in links.
Alternatively, you can measure your existing chain’s length in inches or centimeters and count the number of links to find a suitable replacement size.