while training with your poles you need to change the roller ski tips time by time. You can sharpen the tip but better is to change the tips. You can order them direct at 4KAAD.com There are roller tips for 9mm shafts and 10mm shafts to glue with hot melt glue . But the smartest solution is the the Change-IT basket system by 4KAAD which you can just change with your hands from the winter baskets.
Roller ski tips need to be changed when you look for the best training and effect with your roller skis.