The most common and most likely answer to this crossword clue is the 2 plus 4 plus 4 letter word ON YOUR BIKE
I've seen this crossword clue in The Guardian
O
N
Y
O
U
R
B
I
K
E
Buddy explains!
The straight part
We know that "Here your panniers/get lost" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case here your panniers/get lost = on your bike.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.