DeWalt DCM571 vs Greenworks GD40BC

These two get cross-shopped more often than you’d expect, given how differently they’re built. The DeWalt DCM571 is a 54V FlexVolt machine with a bike handle, designed around pushing a metal blade through brambles and light woody scrub. The Greenworks GD40BC runs on the 40V G40 platform and leads with a genuinely wide 40 cm line cutting width, with a battery already in the box. Both can technically run a blade, so the real question is which one was actually engineered for the job you have.

At a glance

	DeWalt DCM571	Greenworks GD40BC
Power system	54V XR FlexVolt, brushless	40V G40, brushless
Cutting attachment	Line or metal blade	Line head and blade both supplied
Cutting width	38 cm	40 cm
Battery	Often sold bare — battery/charger extra	4 Ah battery commonly included
Battery platform	DeWalt XR/FlexVolt (wide trade-tool range)	Greenworks G40 (40+ garden tools)
Best suited to	Brambles, scrub, light woody growth	Open grass, medium-to-large lawns
Our rating	8.2	8.0

Power and what each is actually built for

On paper, 54V beats 40V, and that gap shows up in how the DeWalt behaves under load. The DCM571’s FlexVolt motor is tuned for torque, which is why DeWalt paired it with a bike handle rather than a simple loop — two-handed control matters once you’re swinging a blade through brambles or a light sapling rather than just spinning line through grass. The Greenworks GD40BC takes a different approach: its 40V G40 motor is tuned to hold line speed across a wide 40 cm swath, which is the standout figure in this comparison and one of the widest cutting widths in its class. Neither figure tells the whole story on its own — the DeWalt’s advantage is torque under resistance, the Greenworks’ is sheer ground coverage on open grass.

The box matters as much as the spec sheet

This is where the two diverge in a way that’s easy to overlook. The Greenworks GD40BC is commonly sold with both a line head and a metal blade in the box, plus a 4 Ah battery, so it’s ready to run either job the day it arrives. The DeWalt DCM571 will also accept a metal blade, and that capability is central to why it has a bike handle in the first place, but it’s frequently sold as a bare tool on the FlexVolt platform — meaning battery, charger, and possibly the blade attachment itself, need checking against the specific listing before you buy. If you’re starting from zero with no existing battery platform, that difference can matter more to your total spend than the headline tool price.

Cutting width vs blade-first design

Line width and blade capability pull in different directions, and each tool leans into one. The Greenworks’ 40 cm cut is genuinely wide for this class, which means fewer passes and faster work across an open lawn, paddock edge, or large garden with nothing woodier than tall grass. The DeWalt’s 38 cm line width is narrower, but that’s not really where it’s trying to win — its bike handle and FlexVolt torque exist to keep a blade steady and controlled through brambles, scrub, and light woody stems that would simply wrap around or stall a line-only setup. If your ground is mixed, with some open grass and some genuinely woody patches, the deciding factor is which task happens more often on your land.

Choose the DeWalt DCM571 if…

• Your ground regularly includes brambles, scrub, or light woody growth that needs sustained blade work
• You already own, or plan to build out, a DeWalt XR/FlexVolt battery collection
• You want a bike handle built specifically around two-handed blade control
• You’re comfortable checking listings carefully for what battery and attachments are actually included

Choose the Greenworks GD40BC if…

• Your work is mostly open grass, lawns, or field margins where a wide cut saves real time
• You want a battery, line head, and blade all included without hunting for a compatible bundle
• You’re building out, or already own, tools on the Greenworks G40 platform
• You’d rather have the widest practical line width in this class than maximum blade torque

Which should you buy?

If brambles, scrub, or light woody growth are a regular part of your ground, the DeWalt DCM571 is the more purpose-built tool — its 54V FlexVolt motor and bike handle exist specifically to keep a blade under control through that kind of resistance, and it’s worth the extra checking on battery and attachment inclusions to get it. If your work is mostly grass, and covering ground quickly matters more than blade torque, the Greenworks GD40BC is the more complete out-of-the-box package, with its wide 40 cm cut, included battery, and both a line head and blade ready to go from day one.

As always with cordless tools, weigh the battery platform as much as the machine itself: DeWalt’s FlexVolt system pays off if you’re already carrying its trade tools, while Greenworks’ G40 platform is built for gardens, not workshops, so pick the ecosystem that matches the rest of what you own.