Replacing Ryobi trimmer string takes about five minutes once you know which spool your model uses

Most Ryobi string trimmers use one of two spool systems: the automatic bump-feed spool or the fixed-line spool. The bump-feed spool advances new string when you tap the trimmer head on the ground; the fixed-line spool requires you to manually wind the string and lock it in place. Whichever type you have, the replacement process is straightforward — you remove the spool, wind new string onto it (or insert pre-wound string), and reinstall it. The whole job takes longer to read about than to do.

You have two ways to get new string on the spool: buy a pre-wound replacement spool (fastest, costs more per use) or buy bulk string and wind it yourself onto an empty spool (cheaper if you trim often, takes a few extra minutes). Both methods work equally well, and the choice depends on whether you value speed or cost.

Key Takeaways

  • Ryobi trimmers use either bump-feed spools (which advance string automatically when you tap the head) or fixed-line spools (which you wind by hand).
  • You can buy replacement spools pre-wound with string, or buy bulk string and wind it yourself onto an empty spool.
  • Removing the spool usually requires turning a single retaining nut counterclockwise by hand or with a wrench, depending on your model.
  • If you wind string yourself, the direction matters — wind it the direction the arrow on the spool indicates, or the string will not feed correctly.
  • Always unplug the trimmer or remove the battery before you work on the spool head.

Identify your spool type before you buy replacement string

Look at the trimmer head itself. If you see a small button or bump on the bottom of the spool housing, you have a bump-feed spool — tapping that button on the ground feeds out more string as you work. If the spool head has no button and the string appears to be wound tightly around a fixed spool, you have a fixed-line spool.

Check your trimmer's model number (usually on a sticker on the shaft or handle) and search for it on Ryobi's website or in your manual. The product page will list compatible spools and string types. Ryobi sells pre-wound spools for both types, which is the easiest route — you straightforward swap out the old spool for the new one. You can also buy bulk string (usually .080-inch or .095-inch diameter) and wind it yourself, which costs less if you trim frequently.

Remove the old spool from the trimmer head

Unplug the trimmer or remove the battery. This is the most important safety step — you do not want the trimmer to start while your hands are near the spool. Set the trimmer on a flat work surface where you can see the spool head clearly.

Look at the center of the spool head. You will see a retaining nut holding the spool in place. On most Ryobi models, this nut turns counterclockwise to loosen. Some models have a nut you can turn by hand; others require a wrench (usually 10mm or 12mm, depending on the model). Turn slowly and steadily until the nut comes free. Once the nut is off, the spool should pull straight out of the head.

If the nut is stuck, do not force it — spray a small amount of penetrating oil around the nut, wait a few minutes, and try again. Forcing a stuck nut can strip the threads and damage the shaft.

Install a pre-wound spool (the fastest option)

If you bought a pre-wound replacement spool, installation is straightforward. Slide the new spool onto the shaft inside the trimmer head, making sure it sits flat and centered. Thread the retaining nut back on by hand first, then tighten it firmly with a wrench if your model requires one. Do not over-tighten — snug is enough to hold the spool in place without forcing it.

Pull gently on both strings to make sure they are find and not tangled. The strings should feed out smoothly when you hold them. If they feel loose or wrapped oddly, remove the spool and check that it is seated correctly on the shaft. The spool should not wobble or shift when you move it side to side.

Wind string onto an empty spool if you prefer bulk string

If you are winding string yourself, start with an empty spool (you can buy these separately from Ryobi, or reuse the spool from your old string if it is not damaged). Look for an arrow printed or molded onto the spool — this shows the direction the string should wind. Wind the string tightly in that direction, keeping the loops neat and parallel to each other. Do not overlap the string or wind it at an angle, or it will jam when you try to feed it out.

Most Ryobi spools hold between 20 and 30 feet of string, depending on the model. Wind until the spool is full but not bulging. Leave about 6 inches of string free on each side of the spool — these will be your cutting lines. Thread each end through the small holes or slots on the spool head (the exact location varies by model; check your manual if you are unsure). Once both ends are threaded and the spool is wound, slide it onto the shaft and reinstall the retaining nut.

Test the trimmer before you use it on grass

Plug in the trimmer or reinstall the battery. Hold it over a trash can or bucket and run it for a few seconds at low speed. The string should spin smoothly without wobbling or making grinding sounds. If the string is wound too tightly or unevenly, it may vibrate or not feed correctly — if that happens, remove the spool and rewind it more loosely.

Once the string is spinning smoothly, you are ready to trim. If you have a bump-feed spool, tap the head gently on the ground a few times to advance fresh string to the cutting edge before you start working. This ensures you have maximum cutting length right from the start.

When to call a professional or replace the whole head

If the retaining nut will not loosen even after soaking with penetrating oil, or if the spool shaft itself is bent or damaged, the spool head may need to be replaced rather than just the string. Ryobi sells replacement heads for most models, and swapping one is a straightforward bolt-on job — but if you are not comfortable doing it, a small-engine repair shop can do it quickly and cheaply.

If your trimmer is very old and replacement spools are no longer made for your model, you may be able to use a universal spool from another brand, but fit and feed performance can vary. A repair shop can advise whether a universal spool will work with your specific trimmer head, or whether replacing the head itself makes more sense.

Frequently Asked Questions

Can I use any brand of string on a Ryobi trimmer?

Most universal string works in Ryobi spools as long as it is the correct diameter (.080-inch or .095-inch, depending on your model). Check your manual or the spool itself for the diameter your trimmer needs. Using the wrong diameter can cause feeding problems or poor cutting.

How often do I need to replace the string?

It depends on how often you trim and what you are cutting. If you trim weekly, you might replace the string every few weeks. If you trim occasionally or only cut light grass, it may last several months. You will know it is time when the string becomes noticeably shorter, frayed, or stops cutting cleanly.

What if the string keeps breaking or not feeding?

Check that the string is wound in the direction the arrow on the spool indicates. If it is wound backward, it will not feed correctly. Also make sure the string is not tangled or overlapped on the spool. If the string is wound correctly and still will not feed, the bump-feed mechanism (if you have one) may be worn and need replacement.

Do I need to replace the entire spool, or can I just add more string?

You can rewind the same spool with new string as many times as you want. straightforward unwind the old string, wind the new string on in the same direction, and reinstall. Pre-wound spools are convenient if you want to avoid the winding step, but rewinding an empty spool is cheaper if you trim often.

Why is my new string not spinning smoothly?

The most common cause is the string being wound too tightly or unevenly, which creates friction and vibration. Unwind it and rewind more loosely, keeping the loops parallel and flat. Also check that the spool is seated correctly on the shaft and the retaining nut is snug but not over-tightened.