Laces in shoes (6)
I believe the answer is:
spikes
This clue could be a double definition.
'laces' is the first definition.
('spike' can be a synonym of 'lace')
'shoes' is the second definition.
The definition and answer can be both man-made objects as well as being plural nouns.
Maybe there's an association between them I don't understand?
'in' is the link.
Can you help me to learn more?
(Other definitions for spikes that I've seen before include "Running shoes" , "Sharp points on athletes' shoes" , "Makes (a gun) useless" , "Prongs" .)