The most common and most likely answer to this crossword clue is the 6 letter word LEVERS
I've seen this crossword clue in Independent
L
E
V
E
R
S
Buddy explains!

The straight part
We know that "bars" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case bars = levers.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does LEVERS mean?
LEVERS noun- (except in generalized senses below) A crowbar.
- A rigid piece which is capable of turning about one point, or axis (the fulcrum), and in which are two or more other points where forces are applied; — used for transmitting and modifying force and motion.
- A small such piece to trigger or control a mechanical device (like a button).
- A bar, as a capstan bar, applied to a rotatory piece to turn it.
- An arm on a rock shaft, to give motion to the shaft or to obtain motion from it.
- To move with a lever.
- To use, operate or move (something) like a lever (physically).
- To use (something) like a lever (in an abstract sense).
- To increase the share of debt in the capitalization of a business.
- A levee.