Fizan's Flexi Expanders could give your stiff trekking poles a new lease of life, check your expanders for wear.
Fizan says: Replaces the part of the Pole that slips inside and provides the locking mechanism. Each pack contains 2 each of all required sizes. Different packs for each type of Fizan pole.
Fizan's Replacement Flexi Expanders could give your trekking poles a new lease of life - if they are stiff to deploy take a close look at the condition of the expanders - if they are worn they should be replaced.