Rock quartet to climb with speed, and then some? (5,8)
I believe the answer is:
mount rushmore
'speed and then some?' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'rock quartet to climb' is the wordplay.
'rock quartet' becomes 'rushmore' (I can't explain this - if you can you should believe this answer much more).
'to' says to put letters next to each other (I've seen this in other clues).
'climb' becomes 'mount' (synonyms).
'rushmore' put after 'mount' is 'MOUNT RUSHMORE'.
'with' acts as a link.
Can you help me to learn more?
(Other definitions for mount rushmore that I've seen before include "Where giant relief carvings of four US presidents are to be seen in South Dakota" , "Where the leaders are stoned" , "national memorial" .)