Become more suitable for steady cycling? (7)
I believe the answer is:
flatter
This clue is a double definition.
'become' is the first definition.
(I know that become can be written as flatter)
'more suitable for steady cycling?' is the second definition.
(eg flatter roads)
(Other definitions for flatter that I've seen before include "Possibly imitate" , "Less hilly; show to advantage" , "resort to cajolery" , "Praise insincerely" , "Please with undue praise" .)