The most common and most likely answer to this crossword clue is the 7 plus 4 letter word DRIVING TEST
D
R
I
V
I
N
G
T
E
S
T
Buddy explains!
The straight part
We know that "It involves manoeuvres to vet street riding" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case it involves manoeuvres to vet street riding = driving test.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.