If you’re anything like me, at some point you might’ve wondered about the difference between straight shaft vs curved shaft string trimmers. My use the word “might’ve” here is definitely tongue-in-cheek. Up until I started researching this article, I had never really invested any thought on the issue. One string trimmer design was the same as any other, at least in my mind. And, if I’m being honest, I’m not entirely sure that I’ve ever been consciously aware any sort of variety existed…Sure, I’ve worked on a few lawn crews over the years, and I work on my own lawn from time to time. But, as far as I’ve been concerned, I’ll use whatever string trimmer is readily available, and probably only if the lawn really needs it. If the available tool works as intended, what’s left to think about?
Then there was the recent best string trimmer shootout which featured exclusively straight shaft models. It seems that’s the preferred form factor for cordless at present, though some curve models do exist.
Of course, for the lawn care professional, or even the more-zealous-than-I-happen-to-be landscaping enthusiast, there is such a thing as making your job easier. Considering which design to use makes sense. Having the right tool for the job at hand will streamline operations, and there is some obvious benefit to “working smarter, not harder.” With that said, I’ve done my research, and learned the error of my ways. Therefore, the focus of this article is to lay out those key differences to help others assess their options, and ultimately, settle on a design that makes for “smarter” work.
The Inner Workings of the Shaft
Let’s look at the string trimmer shaft and its function. In both curved and straight shaft trimmers, a motor connects to a cutting head by way of a shaft. The shaft on both models is going to be where the handle and the throttle are mounted. Within the metal shaft, a drive cable runs the length of the shaft, spun by the engine, and turns the cutting head at the other end of the trimmer.
The curve of the shaft, or lack thereof, will influence the drive cable. In a model like the Makita brushless curved shaft string trimmer, the drive cable will need to be flexible to accommodate the curve in the shaft. This will have a direct effect on the durability of the cable, as the drive cable constantly bends and spins within the metal shaft. This shouldn’t be too much of a concern with light or moderate use. However, the professional user will probably look for more durability.
In a straight shaft system like the EGO Power Head string trimmer, the drive cable accomplishes the same function, but since there is no curve to account for, the cable is less vulnerable to breakage. The straight shaft design can be accommodating as to what type of driving mechanism the string trimmer employs. Straight shaft string trimmers can employ a variety of driving mechanisms, from steel cables to solid steel drive shafts. Because the drive cable/shaft experiences less bending, straight shaft trimmers tend to be more durable.
Straight Shaft vs Curved Shaft String Trimmers
Aside from the aforementioned durability considerations, both the curved shaft and the straight shaft design have their own respective pros and cons to consider.
Curved Shaft String Trimmers
A curved shaft usually means a shorter shaft. This results in a lighter string trimmer, which can be beneficial for longer jobs. Curved shaft trimmers also tend to feel well-balanced, which helps with maneuverability in close areas. Because of their reduced length and weight, curved shaft trimmers might be the preferred option for shorter folks, as well as people who only have a smaller area to manage. You can manage yards that require less heavy duty trimming more quickly and easily with this design. Curved shaft string trimmers also tend to cost less than their straight shaft counterparts.
The curved shaft design does have its cons, though. For one thing, taller people will be forced to bend over, which can become uncomfortable. The curved shaft can also get in the way when trying to get under lawn furniture or underbrush.
For another thing, because of the arched driveline, the curved shaft trimmer will generate less torque and cutting power than a straight shaft would allow. As previously stated, the lifespan of the drive cable typically loses to a straight shaft. However, due to the curve, a cable driveline remains the only option for the curved shaft user. In fact, the available options generally become very limited with this string trimmer. Curved shafts usually won’t accommodate attachments, and users tend to be relegated to the world of lighter duty nylon string. These negatives won’t outweigh the benefits for the casual user, but the Pro will opt for the heavier duty straight shaft.
Straight Shaft String Trimmers
The straight shaft design is more functional. First of all, the straight shaft will be longer, which extends the reach. Taller people will enjoy this feature as it will save some back pain with extended use. Also, a level driveline will generate less vibration, and because of a lower gear reduction, a straight shaft trimmer will generate more torque. The straight shaft string trimmer will provide a more comfortable experience on a long enough timeline.
Secondly, the straight shaft trimmer will be much more flexible and attachment-capable. Because of the greater torque and power, the user can fit the cutting head with a variety of string gauges. Metal blades can replace string should the need ever arise. Plenty of straight shaft models have features that allow the cutting head to be removed altogether and replaced with a different attachment head. Some options include pole saws, edgers, hedge clippers, or even cultivators for tilling.
In the straight shaft vs curved shaft string trimmers argument, the straight shaft design will lose some points when it comes to weight and cost. Because of the extended shaft, the straight shaft string trimmer typically weighs more and feels less balanced than the curved shaft. Shorter people might struggle with this design as well. Because professionals are likely to use straight over curved shafts, the increased quality of the components also drives up the price. Pro grade models tend to include more features, further affecting the price point.
OK, Sum It Up Already!
To summarize the straight shaft vs curved shaft string trimmers argument…both have their benefits and their weaknesses. However, when considering straight shaft vs curved shaft string trimmers, your intentions matter. Do you work with these tools daily? Are you casual homeowner with a small yard? Are you tall or short?
Curved shaft string trimmers will appeal mostly to homeowners who don’t need to use it every day. They also work better for users who don’t have a lot of ground to cover. A lighter and more balanced unit provides better maneuverability, assuming that you won’t have to get under too many obstacles. Those who might be vertically challenged might appreciate a string trimmer that isn’t as tall as they are. If your trimming needs focus primarily around grass and weeds, the curved shaft could stand out as a “smarter” option. This weighs even further considering the lower average cost.
Straight shaft string trimmers will make a lot of sense for those who require a more functional and durable option. Professionals who pick up a trimmer 15 times a day will, no doubt, benefit from the increased durability and power that the straight shaft provides. When time is money, the ability to move through a job quickly becomes paramount. And, with the extended reach a straight shaft provides, you’ll likely spend less time bending over. This will save you some stress on your lower back. Functionally, the variety of attachments a straight shaft accommodates will open this trimmer up to a variety of applications.