If your poles are slipping there are various ways to combat the issue. The Leki Expander for Classic Lock – Red 14mm is a great choice.
Separate your poles and let the insides dry, worth doing regularly.
Clean the inside with cloth
Replace the expanders (red for older poles, black, blue or green split dowels for current poles
Scrub the insides of the poles with Leki cleaning brushes and brush out any dust created with cloth.
If you have trekking poles, take the smallest section out and turn it around, if the black tip doesn’t go all the way in then you need the classic line brushes (and 16 and 18 mm expanders or split dowels). If it goes all the way in then you need the Lite brushes and 14 and 16mm expanders or split dowels depending on what your pole has on the end of the sections).
Blue and Black split dowels are fitted in Classic size poles and Green and Blue in Lite and Ultralight poles.
The brushes come with two black adapters that enable you to attach them to the end of either a screw on or split dowel pole to help you clean out your poles.