Top positive review
5.0 out of 5 starsexcellent if use 3rd party trimmer head
Reviewed in the United States on January 2, 2014
This trimmer does have very serious issues, as reported by the negative reviews. The problem is that all the electric trimmers are quite poor, according to the reviews.
The greenworks does have plenty of power, which makes it well worth the price by itself. The main issue is the trimmer head which does not release line and it very frequently sucks the line back through the hole so you have to restring. You have to pull both ends of line while pushing the center bumphead button and it will take many attempts for each successful release of line. I became very skilled at restringing, even with poor instructions, but it is still inconvenient to spend 90% of your time restringing or struggling to pull out some line so you can do a little more trimming. I followed one reviewer's advice to have Greenworks send out a replacement trimmer head. It seemed to be a little better but still awful. My old Ryobi bumpfeed, which finally wore out, had the same problem but nowhere near as bad. This is a one star trimmer, basically unusable without modification.
I saw two 3rd party trimmer heads being used with this greenworks in the greenworks reviews or trimmer head reviews. I tried the pivotrim pro, since one guy said he couldn't get the tanaka 32308 to fit (it may be more difficult even after you remove the shaft extension). This trimmer becomes five stars with the commercial trimmer head. It has plenty of power for any 3rd party trimmer heads, which are usually only used on gas trimmers. I only used two looped lines on the pivotrim, which seemed to be plenty, instead of all four. It cuts close to the ground, too. It is industrial power and more dangerous as some reviewers have mentioned. You should have goggles (a face shield would be better), long pants, shirt, covered shoes, and hearing protection. Cover your glass doors and windows, too, if you have small rocks or gravel in your yard. It rips through dirt and rocks and will shatter glass. It cuts through bunch grass with little problem, though the pivotrim will break line right at the loop sometimes when it gets really tough. It is also a little harder to handle because of the power.
If, like me, you do have a problem with the greenworks trimmer head, try a 3rd party trimmer head on the greenworks trimmer. If your current trimmer just has a worn out trimmer head you might be able to just replace it without buying a whole new trimmer. You can always buy the greenworks trimmer later or the 3rd party trimmer head later if either doesn't fit or work. Greenworks does not recommend that you use a 3rd party trimmer head. They also say you should not use size 95 line, even though it says 80 or 95 right on the original trimmer head. I think it will actually take 65 line, too, if that's all you have.
Use the pivotrim method 4:
1. remove the spool
2. rotate the shaft and cylinder until the cylinder hole lines up with the hole in the nonrotating core inside
3. put a screwdriver or metal rod through the hole to lock the shaft extension
4. turn the shaft extension nut clockwise with a socket wrench or regular wrench (it should come off fairly easily)
5. one of the included pivotrim nuts threads easily onto the threaded base shaft
You'll want to get the thickest, 105, and highest quality line that still fits for the pivotrim. The orange precut hex line breaks at the loop almost instantly because it is too cheap. My 105 round line barely fit through the loop holes so 105 hex edge line may or may not fit.
The greenworks does have other issues I can live with. The trigger is very hard to keep pressed, as mentioned by others, and you have to keep it pressed all the way down. I put one finger over another finger but I still have to rest my finger after a few minutes. The trimmer itself is heavy but not enough to be a real problem. This could be a serious drawback for someone of below average size and strength, though. The main trimmer shaft did pop out on me once, but was fine after putting it back in the hole again. The cord retainer only works on very small gauge extension cords. It is functional if you push the looped cord through the front and loop it back around, but you are much better off just tying the connection with an overhand knot the same as securing two extension cords together.
This is probably the only viable electric trimmer. I highly recommend it when used with an upgrade trimmer head.
12 Jan 2016 Update:
When my pivotrim pro broke down to almost nothing left I replaced it with a Tanaka 32308 trimmer head. It installs easy enough, especially if you are just switching between a pivotrim and a Tanaka, but the Tanaka with two string ends doesn't have near the power of the pivotrim with two double string ends, which you will need for tall tough grass.
You can bypass the hard to press button problem with a velcro strap. I bought the 8 inch velcro cable ties from Swiss Precision to cinch down the button below and trigger on top before use. It's a little bit of a pain but a lot less pain than resting your fingers between runs.
