Revolutionary move to go on the wagon (9)
I believe the answer is:
cartwheel
'revolutionary move' is the definition.
(I've seen this before)
'go on the wagon' is the wordplay.
'go' becomes 'wheel' (wheeling is a kind of going).
'on' means one lot of letters go next to another.
'the wagon' becomes 'cart' (cart is a kind of wagon).
'wheel' put after 'cart' is 'CARTWHEEL'.
'to' acts as a link.
(Other definitions for cartwheel that I've seen before include "Gymnastic feat" , "Acrobat's manoeuvre" , "liable to get into a rut?" , "Acrobatic movement" , "revolutionary movement" .)