Friendly rowing mate, geek, mainly after spring loop that holds right bit (8,7)
I believe the answer is:
sparring partner
'rowing mate geek mainly after spring loop that holds right bit' is the definition.
'sparring partner' can be an answer for 'rowing mate' (I've seen this in another clue). I'm not certain of the rest of the definition.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for sparring partner that I've seen before include "jabber" , "whose attacks are helpful, in practice?" , "Argumentative friend" , "Ring mate" , "disputatious associate" .)