Dull roller ferrules slip, and slipping poles cause blisters, poor technique, and even an occasional fall if you're really hammering. As the pavement turns colder and harder in the fall, poles tend to slip even more. Attempts to pound a dull pole into pavement to make it stick causes wrist and elbow pain. And those of us skiing behind you really don't look forward your pole slipping into us...
Sharp pole tips make for better rollerskiing.
Three different pole tips could be used for rollerskiing: steel tips found on cheap ski poles, carbide tips found on better quality ski baskets, and carbide tips bound on rollerski ferrules.
Avoid using cheap baskets; steel tips dull amazingly fast. (If you're reading this article, it's unlikely you have poles with steel tips). That leaves baskets with carbide tips and roller ferrules.
Rollerski Ferrules vs. Ski Baskets
Three main features differentiate a ferrule from a normal ski pole basket:
The rollerski ferrule (left) has a longer tip, no basket, and the tip extends deeper into the plastic than a normal ski basket (right).
There are exceptions: I have seen normal baskets with long tips, and ferrules with short tips, but in general, ferrules have the most exposed carbide.
Which to use? If you don't rollerski much, use your regular poles. If you're cheap and have a source of free ski baskets (and the first kilometer of a mass start race is an excellent place to find broken ski poles with attached racing baskets), you can create your own ferrule by hacking off the basket. When the tip gets too dull to sharpen, toss it away and put on a "new" one. If you live to rollerski, ferrules might be more cost effective in the long run.
In a perfect world, you would sharpen the ferrule first along the white line, then along the black.
What Surface to Sharpen?
Ski poles generally have two angles cut into the tip, represented by the white and black lines in the photo at the right (the angles are quite visible on the right tip). These are the only surfaces of the tip that need sharpening.
People who sharpen their tips on other surfaces - especially the surface opposite the white lined surface - usually end up making their tips duller or less able to dig into the asphalt because the angle produced is too square. Stick with the white and black surfaces...
Next Time - We haven't actually talked about tools for sharpening poles! Hint: you're nail file ain't gonna do it... In the next installment, we'll visit the common diamond file and lowly bench grinder. Till then - get out and rollerski!