The most common and most likely answer to this crossword clue is the 9 letter word PATROLMEN
I've seen this crossword clue in Independent
P
A
T
R
O
L
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The straight part
We know that "parking Montreal cycles (9)" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case parking montreal cycles (9) = patrolmen.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 PATROLMEN mean?
PATROLMEN noun- A police officer, especially a junior officer assigned patrol duty instead of detection or supervision.