It's all the rage over detective getting on your bike (3,2)
I believe the answer is:
hop it
'on your bike' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'it's all the rage over detective' is the wordplay.
'it's all the rage' becomes 'hot' (I can't explain this - if you can you should believe this answer much more).
'over' indicates putting letters inside.
'detective' becomes 'pi' (I've seen this in other clues).
'hot' enclosing 'pi' is 'HOP IT'.
'getting' is the link.
Can you help me to learn more?
(Other definitions for hop it that I've seen before include "Run along now!" , "Go away (colloq.)" , "Scram!" , "Clear off!" , "Skedaddle!" .)