Pine's great new selection for a hill climber (5,4)
I believe the answer is:
first gear
'a hill climber' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I don't see?
'pine's great new selection' is the wordplay.
I cannot really see how this works, but
an anagram of 'great' is 'tgear' which is within the answer.
The remaining letters 'firs' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'for' acts as a link.
Can you help me to learn more?
(Other definitions for first gear that I've seen before include "infants' clothes" , "It's engaged, for a start" , "What may be selected in a vehicle" .)