Walker’s tip: to speed up? (6)
I believe the answer is:
toecap
'walker's tip' is the definition.
'toecap' can be an answer for 'tip' (I have seen 'Tip of shoe' mean 'toecap' so perhaps 'tip' could also mean 'toecap'). I am unsure of the 'walker's' bit.
'to speed up?' is the wordplay.
'speed' becomes 'pace' (pace is a kind of speed).
'up?' says the letters should be written in reverse (in down clue: letters go upwards).
'pace' reversed gives 'ecap'.
'to'+'ecap'='TOECAP'
Can you help me to learn more?
(Other definitions for toecap that I've seen before include "Boot or shoe item" , "Capote (anag.)" , "part of footwear" , "part of Oxford, perhaps" , "Protective cover on boot or shoe" .)