User of products from top line machine might have these uncomfortable feelings when cycling (7,3,4)

'these uncomfortable feelings when cycling' is the definition.
(you might get needles and pins when cycling)

'user of products from top line machine might have' is the wordplay.
I cannot really understand how this works, but
'from' could be 'in' (I've seen this in other clues) and 'in' is found in the answer.
'line' could be 'l' (used when specifying particular lines from a poem) and 'l' is found within the answer.
'have' could be 'need' (synonyms) and 'need' is present in the answer.
This explanation may well be incorrect...

Can you help me to learn more?