My lead-free scooter managed around 150 -- fast vehicle (10)
I believe the answer is:
motorcycle
'fast vehicle' is the definition.
'my lead-free scooter managed around 150' is the wordplay.
'lead-free' means to remove the first letter (the letter which leads the word is removed).
'managed' indicates an anagram.
'around' means one lot of letters goes inside another.
'150' becomes 'cl'.
'scooter' with its first letter taken off is 'cooter'.
'my'+'cooter'='mycooter'
'mycooter' with letters rearranged gives 'motorcye'.
'motorcye' going around 'cl' is 'MOTORCYCLE'.
(Other definitions for motorcycle that I've seen before include "Triumph for rider, perhaps" , "It's used for scrambling" , "transport" , "Petrol-driven two-wheeler" , "Two-wheeled vehicle" .)