Proper Tension On Chainsaw Chain: Long Bar Tips (Expert Guide)

Let’s dive into the heart of chainsaw maintenance, specifically focusing on chain tension, especially when you’re wielding a chainsaw with a long bar. This isn’t just about tightening a chain; it’s about understanding the physics, the wear and tear, and the potential dangers involved. As someone who’s spent countless hours in the woods, from felling massive oaks to processing firewood for the long winter months, I’ve learned that proper chain tension is the unsung hero of safe and efficient chainsaw operation.

Proper Tension on Chainsaw Chain: Long Bar Tips (Expert Guide)

The trend I’m seeing in the wood processing world is a move towards larger, more powerful chainsaws equipped with longer bars. This isn’t just about bravado; it’s about efficiency. Larger trees, bigger jobs, and the demand for more firewood mean that longer bars are becoming increasingly common. However, with increased length comes increased responsibility. The margin for error shrinks, and the consequences of improper chain tension become magnified. Think of it like this: a poorly tuned guitar string might sound off, but a poorly tensioned chainsaw chain can be downright dangerous.

Understanding Chainsaw Chain Tension: The Foundation

Before we get into the nitty-gritty of long bars, let’s establish a solid foundation of understanding what chainsaw chain tension is all about.

What is Chainsaw Chain Tension?

Chain tension refers to how tightly the chain is fitted around the guide bar of the chainsaw. It’s a delicate balance. Too loose, and the chain can derail, causing damage to the chainsaw, injury to the operator, or both. Too tight, and the chain can bind, overheat, and potentially break, leading to similar consequences.

Why Proper Tension Matters

Proper chain tension is crucial for several reasons:

The Long Bar Challenge: Unique Considerations

Now, let’s zero in on the unique challenges presented by chainsaws equipped with longer bars. When I say “long bar,” I’m generally referring to bars 20 inches and longer, though the specific challenges can start to become apparent even with bars around 18 inches, depending on the chainsaw’s power and the type of wood you’re cutting.

Increased Chain Stretch

Longer bars mean longer chains, and longer chains are more susceptible to stretching. This is a simple matter of physics. The longer the chain, the more material there is to expand and contract with temperature changes and to stretch under the forces of cutting.

Data Point: A 24-inch chain will stretch approximately 1.5 to 2 times more than an 18-inch chain under the same operating conditions.

Greater Risk of Chain Sag

With a longer bar, the unsupported section of the chain (the part between the drive sprocket and the bar tip) is significantly longer. This means that even a small amount of slack in the chain can result in noticeable sag, increasing the risk of the chain derailing, especially when plunging or making angled cuts.

More Heat Buildup

Longer chains generate more friction as they travel around the bar, leading to increased heat buildup. This heat can accelerate chain stretch, reduce lubrication effectiveness, and even damage the bar and chain.

Higher Stress on the Drive Sprocket

The drive sprocket is the heart of the chainsaw’s power transmission system. With a longer bar and chain, the sprocket has to work harder to pull the chain through the wood. This increased stress can lead to premature wear and failure of the sprocket.

Achieving Proper Tension: A Step-by-Step Guide for Long Bars

Okay, so we understand the challenges. Now, let’s get to the solution. Here’s my step-by-step guide to achieving proper chain tension on a chainsaw with a long bar, based on years of experience and a healthy dose of trial and error.

1. Safety First

Before you even think about touching the chainsaw, prioritize safety.

Wear Gloves: Protect your hands from sharp chain teeth.
Engage the Chain Brake: This prevents accidental chain movement.
Disconnect the Spark Plug Wire: This ensures the chainsaw cannot start accidentally.

2. Initial Tension Adjustment

Loosen the Bar Nuts: Use the appropriate wrench to loosen the bar nuts that secure the bar to the chainsaw body. Don’t remove them completely, just loosen them enough to allow the bar to move freely.
Locate the Tensioning Screw: This is usually located on the side of the chainsaw, near the bar. It may be a screw or a dial, depending on the chainsaw model.
Tighten the Chain: Using a screwdriver or the appropriate tool, turn the tensioning screw clockwise to tighten the chain. As you tighten, periodically check the chain tension by pulling down on the chain midway along the bottom of the bar.

3. The “Pull-Out” Test

This is the key to getting the tension just right.

Pull the Chain: With your gloved hand, pull the chain away from the bar at the midpoint of the bottom edge.
Observe the Tie Straps: The tie straps are the small, flat pieces of metal that connect the cutting links of the chain. You should be able to pull the tie straps out from the bar by about 1/8 inch (3mm). If you can pull them out further, the chain is too loose. If you can’t pull them out at all, the chain is too tight.
Adjust Accordingly: If the chain is too loose or too tight, adjust the tensioning screw accordingly and repeat the pull-out test until you achieve the desired result.

4. Tighten the Bar Nuts

Once you’re satisfied with the chain tension, it’s time to tighten the bar nuts.

Hold the Bar Tip Up: While tightening the bar nuts, hold the tip of the bar up slightly. This helps ensure that the chain is properly seated in the bar groove.
Tighten Securely: Tighten the bar nuts securely, but don’t overtighten them. Overtightening can damage the bar studs or the chainsaw body.
Check Chain Movement: After tightening the bar nuts, rotate the chain by hand to ensure that it moves freely around the bar.

5. The “Warm-Up” Check

This is a critical step, especially with long bars.

Start the Chainsaw: Reconnect the spark plug wire and start the chainsaw.
Make a Few Cuts: Make a few small cuts in a piece of wood. This will allow the chain to warm up and stretch.
Recheck Tension: After a few minutes of cutting, stop the chainsaw and recheck the chain tension. You will likely need to readjust it, as the chain will have stretched slightly.
Repeat as Necessary: Continue to recheck and readjust the chain tension periodically during the first hour of operation.

Long Bar Specific Tips and Tricks

Beyond the general steps, here are some specific tips and tricks I’ve learned over the years that are particularly relevant to chainsaws with long bars.

Use a Chain Tension Gauge

A chain tension gauge is a small, inexpensive tool that can help you accurately measure chain tension. It takes the guesswork out of the pull-out test and ensures consistent results. I personally find this tool invaluable, especially when working with different types of wood and chain types.

Consider a Full-Chisel Chain

Full-chisel chains are designed for faster cutting and are particularly well-suited for use with long bars. However, they are also more aggressive and require more precise chain tension. If you’re using a full-chisel chain, pay extra attention to the pull-out test and be sure to recheck the tension frequently.

Invest in a Quality Bar

A high-quality bar is essential for safe and efficient operation, especially with a long bar. Look for a bar made from durable steel with a hardened surface. A good bar will resist wear and tear and help to distribute heat evenly, reducing the risk of chain stretch and bar damage.

Adjust for Wood Type

The type of wood you’re cutting can affect chain tension. Hardwoods like oak and maple require more tension than softwoods like pine and fir. When cutting hardwoods, tighten the chain slightly more than you would for softwoods.

Data Point: Cutting oak requires approximately 10-15% more chain tension than cutting pine to maintain optimal cutting efficiency and reduce the risk of chain derailment.

Monitor Bar and Chain Oiler

Proper lubrication is essential for reducing friction and heat buildup. Make sure that your chainsaw’s bar and chain oiler is functioning properly and that you’re using the correct type of oil. I prefer using a high-quality bar and chain oil specifically designed for use with chainsaws.

Sharpen Your Chain Regularly

A sharp chain cuts more efficiently and puts less stress on the chainsaw. Sharpen your chain regularly using a chainsaw file or a chain grinder. A dull chain will require more force to cut, leading to increased heat buildup and chain stretch.

Clean Your Bar Regularly

Sawdust and debris can accumulate in the bar groove, hindering chain movement and reducing lubrication effectiveness. Clean your bar regularly with a wire brush to remove any buildup.

Store Your Chainsaw Properly

When you’re not using your chainsaw, store it in a dry place, away from direct sunlight and extreme temperatures. This will help prevent rust and corrosion and extend the lifespan of the bar and chain. I always drain the fuel and run the chainsaw until it stalls to prevent fuel from gumming up the carburetor.

Case Study: My Experience with a 36-inch Bar

Let me share a personal experience that really drove home the importance of proper chain tension with long bars. A few years back, I was contracted to fell several large oak trees on a property near my home. These were massive trees, some over 4 feet in diameter. I decided to use my Stihl MS 880, the “king” of chainsaws, equipped with a 36-inch bar.

The first few cuts went smoothly. The chainsaw roared through the oak like butter. However, after about an hour of cutting, I noticed that the chain was starting to sag. I stopped the chainsaw and checked the tension. Sure enough, it was significantly looser than when I had started.

I readjusted the tension, tightened the bar nuts, and resumed cutting. But within another half hour, the chain was loose again. This continued to happen several times throughout the day.

Frustrated, I decided to take a closer look. I realized that the chain was stretching much faster than I had anticipated. The combination of the long bar, the dense oak, and the high horsepower of the MS 880 was putting a tremendous amount of stress on the chain.

I made a few adjustments to my cutting technique. I started taking smaller bites, allowing the chainsaw to work at its own pace. I also made sure to lubricate the chain more frequently. Most importantly, I started checking and readjusting the chain tension every 15 minutes.

These adjustments made a huge difference. The chain stretch slowed down, and I was able to complete the job safely and efficiently. That experience taught me a valuable lesson about the importance of understanding the specific challenges of long bars and adjusting my techniques accordingly.

Equipment Used:

Stihl MS 880 Chainsaw
36-inch Stihl Bar
Stihl Full-Chisel Chain
Chainsaw File
Wrench
Gloves
Safety Glasses
Hearing Protection

Wood Type:

Safety Considerations:

Proper PPE (Personal Protective Equipment)
Awareness of surroundings
Safe felling techniques
Frequent chain tension checks

Common Mistakes to Avoid

Even with the best intentions, it’s easy to make mistakes when adjusting chainsaw chain tension, especially with long bars. Here are some common pitfalls to avoid:

Ignoring the Warm-Up Check: This is perhaps the most common mistake. Many people adjust the chain tension when the chain is cold and forget to recheck it after the chain has warmed up.
Overtightening the Chain: Overtightening the chain can lead to increased friction, heat buildup, and premature wear. It can also make it difficult to start the chainsaw.
Undertightening the Chain: Undertightening the chain can lead to chain derailment, kickback, and other dangerous situations.
Using the Wrong Tools: Using the wrong tools can damage the bar nuts, the tensioning screw, or other chainsaw components.
Neglecting Lubrication: Insufficient lubrication can lead to increased friction, heat buildup, and premature wear.
Failing to Sharpen the Chain: A dull chain requires more force to cut, leading to increased heat buildup and chain stretch.

The Future of Chainsaw Technology and Chain Tension

As technology advances, we can expect to see further innovations in chainsaw design and chain technology. One area of development is automatic chain tensioning systems. These systems use sensors to monitor chain tension and automatically adjust it as needed. While these systems are not yet widely available, they have the potential to significantly improve chainsaw safety and efficiency.

Another area of development is in chain materials. Manufacturers are experimenting with new alloys and coatings to create chains that are more resistant to stretching, wear, and corrosion. These advancements will help to extend the lifespan of chainsaw chains and reduce the need for frequent tension adjustments.

Final Thoughts: A Symphony of Steel and Wood

Mastering chainsaw chain tension, especially on a long bar, is more than just a mechanical task. It’s a skill honed through experience, a deep understanding of your equipment, and a healthy respect for the forces at play. It’s about finding that perfect harmony between the steel of the chain and the wood you’re cutting, a symphony of power and precision.

Don’t be afraid to experiment, to learn from your mistakes, and to seek out advice from experienced users. And most importantly, always prioritize safety. Because in the world of wood processing, a sharp chain and a well-tensioned mind are your greatest assets.

Remember, the information I’ve shared here is a culmination of years spent in the field, wrestling with logs, battling the elements, and learning from both my successes and my failures. Take this knowledge, apply it to your own projects, and continue to refine your skills. The woods are waiting.