E.g. Mamil when sporting lurid ergonomic clothes (5)
I believe the answer is:
rider
'e g mamil' is the definition.
(term for a cyclist - 'middle-aged man in lycra')
'sporting lurid ergonomic clothes' is the wordplay.
'clothes' indicates the answer is hidden within the clue (the letters clothe the hidden word).
'RIDER' is hidden within 'sporting lurid ergonomic'.
'when' acts as a link.
(Other definitions for rider that I've seen before include "One on a horse or cycle" , "Additional bit" , "One who's got up" , "Person on horseback" , "given little weight" .)