How To Tension A Chainsaw Chain On Long Bars (Pro Arborist Tips)

Okay, let’s dive into the nitty-gritty of tensioning a chainsaw chain on long bars. It’s a skill that separates the pros from the… well, let’s just say those who spend more time wrestling with a dull chain than actually cutting wood. I’ve spent years in the woods, from thinning pine plantations to tackling massive oaks in urban settings. I’ve seen firsthand the frustration (and danger) of a poorly tensioned chain, especially when you’re dealing with the added length of a long bar. This isn’t just about making a saw run smoother; it’s about safety, efficiency, and extending the life of your equipment. I’m going to share my hard-earned knowledge to help you master this essential technique. Forget quick fixes; we’re building a foundation of understanding.

How to Tension a Chainsaw Chain on Long Bars (Pro Arborist Tips)

A properly tensioned chain is crucial for safe and efficient chainsaw operation, especially when using longer bars. A loose chain can derail, causing injury or damage to the saw. Too tight, and you risk premature wear and tear on the bar, chain, and drive sprocket. Long bars magnify these issues, making precise tensioning even more critical.

Understanding the Basics: Chain Tension Terminology

Before we get into the step-by-step, let’s define some key terms:

Chain Pitch: The distance between any three consecutive rivets on the chain, divided by two. Common pitches are .325″, 3/8″, and .404″.
Chain Gauge: The thickness of the drive links (the part of the chain that sits in the bar groove). Common gauges are .050″, .058″, and .063″.
Drive Links: The teeth on the chain that engage with the drive sprocket.
Bar Groove: The slot in the chainsaw bar that the drive links run in.
Tensioning Screw: The screw that adjusts the position of the bar, thus affecting chain tension.
Side Cover: The cover that protects the clutch, sprocket, and bar mounting area.
Chain Catcher: A safety device that catches a broken or derailed chain, preventing it from flying back towards the operator.

Why Long Bars Demand Extra Attention

Longer bars (typically 20 inches or more) are fantastic for felling larger trees and reaching difficult spots. However, they also present unique challenges:

Increased Chain Sag: The longer the chain, the more it will sag under its own weight. This makes accurate tensioning more difficult.
Greater Friction: A longer chain has more contact with the bar, leading to increased friction and heat. Proper tension is crucial to minimize this.
Higher Risk of Kickback: While kickback is a risk with any chainsaw, longer bars can exacerbate the problem if the chain isn’t properly maintained.

Step-by-Step Guide to Tensioning a Chainsaw Chain on Long Bars

Here’s my tried-and-true method, refined over years of felling and limbing:

Step 1: Safety First!

Engage the Chain Brake: Always, always engage the chain brake before making any adjustments.
Wear Gloves: Protect your hands from sharp chain teeth.
Turn Off the Saw: Make sure the engine is completely off. Never adjust the chain while the saw is running.
Cool Down Period: Allow the saw and bar to cool down if you’ve been using it. Heat expands the metal, affecting tension.

Step 2: Loosen the Bar Nuts

Locate the Bar Nuts: These are typically located on the side cover, near the base of the bar.
Use a Combination Wrench or Scrench: This is a specialized tool that combines a screwdriver and a wrench for chainsaw maintenance.
Loosen, Don’t Remove: Loosen the bar nuts just enough so that you can move the bar with some effort. You don’t want them completely off, as this can make reassembly more difficult.

Step 3: Locate the Tensioning Screw

Side-Mounted Tensioner: Most modern chainsaws have a tensioning screw located on the side of the saw, often accessible through a hole in the side cover.
Front-Mounted Tensioner: Some older models have the tensioner located at the front of the saw, near the bar.
Internal Tensioner: A few saws have an internal tensioner, requiring the side cover to be removed for adjustment. This is less common on professional-grade saws designed for long bars.

Step 4: Adjust the Chain Tension

Lift the Bar Tip: This is crucial. Use one hand to lift the tip of the bar upwards. This removes the slack from the underside of the chain.
Turn the Tensioning Screw:
- Clockwise (Tighten): Turning the screw clockwise will move the bar outwards, tightening the chain.
- Counter-Clockwise (Loosen): Turning the screw counter-clockwise will move the bar inwards, loosening the chain.
The Sweet Spot: Aim for a tension where the chain can be pulled down slightly from the bar, about 1/8 inch (3mm) to 1/4 inch (6mm) at the midpoint of the bar. You should be able to easily pull the chain around the bar by hand. The drive links should remain seated in the bar groove.
Long Bar Adjustment: With long bars, I find it helpful to over-tension slightly while lifting the bar tip, then slowly loosen until I reach the desired play. This compensates for the increased sag.
A Trick I Use: I often use a small piece of wood or a screwdriver handle to gently push down on the chain while tensioning. This helps me visualize the amount of sag.

Step 5: Tighten the Bar Nuts

Maintain Bar Tip Lift: While tightening the bar nuts, continue to hold the bar tip upwards. This prevents the bar from shifting and losing the tension you just set.
Tighten Securely: Tighten the bar nuts firmly, but don’t overtighten. You want them snug enough to hold the bar in place, but not so tight that you risk stripping the threads. I use a torque wrench set to the manufacturer’s specifications whenever possible. Typically, this is around 14-17 Nm (10-12 ft-lbs).
Alternating Tightening: Tighten the bar nuts in an alternating pattern (like tightening lug nuts on a car wheel) to ensure even pressure.

Step 6: The Final Check

Rotate the Chain: Release the chain brake and manually rotate the chain around the bar. It should move smoothly and freely. If it feels tight or binding, loosen the tension slightly.
Chain Sag Test: Hold the saw horizontally and observe the chain sag. It should be minimal.
Drive Link Check: Make sure all the drive links are fully seated in the bar groove.
Visual Inspection: Double-check that the bar is properly seated against the saw body and that the bar nuts are securely tightened.

Step 7: The “Hot Check” (Critical for Long Bars)

Start the Saw: After tensioning, start the saw and make a few test cuts into a piece of wood.
Observe Chain Tension: After the test cuts, stop the saw and check the chain tension again. The chain will often loosen slightly as the metal heats up and expands.
Re-Adjust if Necessary: If the chain is too loose, repeat steps 4-6 to re-tension. This “hot check” is especially important when using long bars, as they are more prone to expansion and contraction.

Pro Arborist Tips for Long Bar Tensioning

Here are some extra tips I’ve learned over the years that can make a big difference:

Chain Break-In: New chains will stretch more than older chains. After installing a new chain, tension it frequently during the first few hours of use.
Bar Rail Maintenance: Keep the bar rails clean and free of debris. Use a bar rail dressing tool to ensure the rails are smooth and even. Uneven rails can cause the chain to bind and wear unevenly.
Proper Lubrication: Use a high-quality bar and chain oil. Proper lubrication reduces friction and heat, which helps maintain chain tension and extends the life of the bar and chain. I prefer a synthetic oil, especially when working in cold weather.
Chain Sharpening: A sharp chain cuts more efficiently and requires less force, reducing stress on the bar and chain. Sharpen your chain regularly using a file or a chain grinder. I use a Stihl 2-in-1 file for quick touch-ups in the field.
Bar Rotation: Rotate the bar regularly (top to bottom) to distribute wear evenly. This helps prevent the bar from developing a “banana” shape.
Inspect Sprocket: Regularly inspect the drive sprocket for wear. A worn sprocket can damage the chain and affect tension.
Temperature Considerations: Ambient temperature affects chain tension. In cold weather, the chain will contract, so you may need to loosen it slightly. In hot weather, the chain will expand, so you may need to tighten it slightly.
Wood Type Matters: Cutting hardwoods (like oak or maple) generates more heat than cutting softwoods (like pine or fir). Adjust your chain tension accordingly. For hardwoods, I tend to run the chain a bit looser.
Chain Choice: Use the correct chain for your saw and the type of wood you are cutting. Using the wrong chain can lead to poor performance and increased wear. I typically use a full-chisel chain for felling and a semi-chisel chain for limbing, as it’s more forgiving in dirty conditions.
Don’t Over-Tension: Over-tensioning the chain is a common mistake. It puts unnecessary stress on the bar, chain, and drive sprocket, leading to premature wear and potential damage. It also increases the risk of kickback.
Listen to Your Saw: Pay attention to how your saw is running. If it sounds strained or the chain is smoking, stop and check the tension.
Keep a Spare Chain: Always carry a spare chain with you in the field. This allows you to quickly replace a damaged or dull chain and keep working.

Real-World Examples and Case Studies

Case Study 1: Felling a Large Oak with a 28-inch Bar

I was hired to remove a large, leaning oak tree that was threatening a house. The tree was about 40 inches in diameter at the base, requiring a 28-inch bar on my Stihl MS 462.

The Challenge: The oak was located on a slope, making it difficult to get a good footing. The tree also had a lot of dead limbs, increasing the risk of falling debris.
The Solution: I started by carefully assessing the tree and planning my felling cut. I used a bore cut to control the direction of the fall. Before making the felling cut, I meticulously tensioned the chain, paying close attention to the “hot check” after the initial cuts.
The Result: The tree fell exactly where I intended it to, without damaging the house. The properly tensioned chain allowed me to make clean, efficient cuts, even in the dense oak wood.

Case Study 2: Bucking Firewood with a 20-inch Bar

I regularly buck firewood using a Husqvarna 455 Rancher with a 20-inch bar.

The Challenge: Bucking firewood can be repetitive and physically demanding. A dull or poorly tensioned chain can make the job even harder.
The Solution: I use a firewood bucking stand to raise the logs off the ground, making it easier to cut them. I also sharpen my chain frequently and check the tension after every few cuts.
The Result: By maintaining a sharp and properly tensioned chain, I can buck a large amount of firewood quickly and efficiently, with minimal fatigue.

Understanding Wood Types and Their Impact on Chain Tension

The type of wood you’re cutting significantly impacts chain tension.

Softwoods (Pine, Fir, Spruce): These woods are generally easier to cut and generate less heat. You can usually run the chain a bit tighter when cutting softwoods.
Hardwoods (Oak, Maple, Hickory): These woods are denser and generate more heat. It’s best to run the chain a bit looser when cutting hardwoods to prevent overheating and binding.
Green Wood vs. Seasoned Wood: Green wood (freshly cut) has a higher moisture content, which can cause the chain to bind. Seasoned wood (dried) is easier to cut and generates less friction.

Tools and Equipment: A Deeper Dive

Chainsaws: For long bars, I recommend professional-grade saws with powerful engines (50cc or larger). My go-to saws are the Stihl MS 462 and the Husqvarna 572XP.
Bars: Choose a bar that is appropriate for the size of your saw and the type of wood you are cutting. I prefer laminated bars for general use and solid bars for heavy-duty applications.
Chains: Use a chain that is compatible with your bar and sprocket. I recommend Oregon and Stihl chains.
Combination Wrench/Scrench: This is an essential tool for chainsaw maintenance.
Chain Sharpener: A chain sharpener is a must-have for keeping your chain sharp. I use a Stihl 2-in-1 file for quick touch-ups and a bench grinder for more extensive sharpening.
Bar Rail Dressing Tool: This tool is used to smooth and even out the bar rails.
Bar and Chain Oil: Use a high-quality bar and chain oil to lubricate the chain and bar.
Torque Wrench: A torque wrench is recommended for tightening the bar nuts to the correct specification.
Safety Gear: Always wear safety glasses, hearing protection, gloves, and chaps when operating a chainsaw.

Drying Methods for Firewood

Since we’re talking about wood processing, let’s briefly touch on firewood drying. Proper drying is crucial for efficient burning.

Air Drying: The most common method. Stack the wood in a well-ventilated area, off the ground, and covered to protect it from rain and snow. Aim for a moisture content of 20% or less. This typically takes 6-12 months, depending on the climate and wood type.
Kiln Drying: A faster method that uses heat to dry the wood. Kiln-dried firewood typically has a moisture content of 10-15%.
Solar Drying: Using a solar kiln can accelerate the drying process.

Strategic Advantages of Proper Chain Tension

Increased Cutting Efficiency: A properly tensioned chain cuts faster and more efficiently, saving you time and energy.
Reduced Wear and Tear: Proper tension reduces stress on the bar, chain, and drive sprocket, extending their lifespan.
Improved Safety: A properly tensioned chain is less likely to derail, reducing the risk of injury.
Better Fuel Economy: A sharp and properly tensioned chain requires less power to cut, resulting in better fuel economy.
Professional Results: A properly maintained chainsaw produces cleaner, more accurate cuts, resulting in a more professional-looking finished product.

Costs, Material Specs, and Timing Estimates

Chainsaw: Professional-grade chainsaws suitable for long bars typically cost between $800 and $1500.
Bars: Bars range in price from $50 to $200, depending on the length and type.
Chains: Chains typically cost between $30 and $50.
Bar and Chain Oil: A gallon of high-quality bar and chain oil costs around $20-$30.
Sharpening: Professional chain sharpening costs around $10-$20 per chain.
Drying Time: Air drying firewood typically takes 6-12 months. Kiln drying takes a few days to a week.
Skill Level: Tensioning a chainsaw chain is a basic skill that can be learned by anyone with a little practice. Sharpening a chain requires more skill and experience.

Challenges Faced by Global DIYers and Small-Scale Logging Businesses

Access to Quality Equipment: In some parts of the world, access to high-quality chainsaws and maintenance tools can be limited.
Training and Education: Proper training and education on chainsaw safety and maintenance are not always readily available.
Financial Constraints: Small-scale logging businesses may have limited financial resources to invest in new equipment and training.
Environmental Regulations: Environmental regulations related to logging and firewood production can vary widely from country to country.
Safety Standards: Safety standards for chainsaw operation may not be consistently enforced in all regions.

Practical Next Steps

Now that you have a solid understanding of how to tension a chainsaw chain on long bars, here are some practical next steps you can take:

Practice on a Shorter Bar: If you’re new to chainsaw operation, start by practicing tensioning on a shorter bar (16-18 inches). This will give you a better feel for the process before moving on to longer bars.
Watch Videos: Watch online videos of experienced arborists demonstrating chain tensioning techniques.
Take a Chainsaw Safety Course: Consider taking a chainsaw safety course offered by a reputable organization. This will provide you with hands-on training and valuable safety information.
Practice Regularly: The more you practice, the better you will become at tensioning your chainsaw chain.
Consult Your Owner’s Manual: Always refer to your chainsaw owner’s manual for specific instructions and recommendations.
Experiment with Different Techniques: Don’t be afraid to experiment with different tensioning techniques to find what works best for you.
Ask for Help: If you’re struggling with chain tensioning, don’t hesitate to ask for help from a more experienced chainsaw operator.

Conclusion

Mastering the art of tensioning a chainsaw chain, especially on long bars, is a fundamental skill for any arborist, logger, or serious woodworker. It’s not just about making your saw run smoother; it’s about safety, efficiency, and prolonging the life of your valuable equipment. By following the steps and tips I’ve shared, and with a little practice, you’ll be able to confidently tackle any cutting task with a properly tensioned chain. Remember, a well-maintained chainsaw is a safe and productive chainsaw. Now get out there and make some sawdust!

How to Tension a Chainsaw Chain on Long Bars (Pro Arborist Tips)