The Practical Rollerskier
Sharp Roller Ferrules Make for Better Skiing - Part II
September 9, 2002 - By Mike Muha
In Part I, we briefly discussed when to use roller ferrules and when to use normal baskets, and which surfaces on the tip to sharpen. Today we go into the tools box...
When you use a diamond file, it's definitely easier to do a little filing each time you ski than waiting for the tips to get really dull.
Second, filing while the diamond file is wet supposedly keeps the file from fouling as much. It's also recommended to rinse the file after using it to clear out the filings.
The Bench Grinder
I also needed a 6", 80-grit silicon carbide grinding wheel - something that would cut through carbide ski pole tips. Unfortunately, Home Depot doesn't carry silicon carbide grinding wheels, but Production Tool Supply (multiple locations in Michigan) down the road did. Cost: about $25 (part number MG37099Z8). You'll also find silicon carbide advertised as "green stone".
Two things you need: good light and some water to dip your pole tips into. The light's for pretty obvious reasons. The water is to cool your pole tip. As the grinding stone cuts away at the tip, it generates heat. The heat can loosen the glue that holds the tip in the plastic housing, or even melt the plastic! So dip frequently!
In the second picture, I'm gently resting the tip against the silicon carbide grinding wheel. "Gentle" is the operative word - let the stone do the work. Pushing too hard will simply create more heat and damage the tip or hurt the stone. Move the tip across the surface of the grinder so the grinding stone wears evenly.
NEVER USE THE SIDE OF THE GRINDING STONE - it can score and cause the stone to disintegrate at a zillion RPM and send projectiles into you!
After a few seconds, dip the pole in water (bottom picture). You don't want to hear the water sizzle - that means you're letting the tip get too warm. Repeat: grind, cool, grind, cool...until the tip is sharp.
You can grind away quite a bit of material, particularly on the long edge of the tip, then change the angle for the final finish edge (see Part 1).
Diamond File or Bench Grinder?
The savings come from two places. First, you don't need to buy as many diamond files (I do keep one around to for some fine tuning - but I've had the same one for two years now). Diamond files cost from $10 to $25 and up.
The other, not so obvious savings, is you don't need to buy roller ferrules as often. After a ferrule has worn to a certain point, it simply becomes too much of a pain to sharpen with a diamond file - or you need an entire diamond file to sharpen them. The result is you tend to replace the ferrules instead of sharpening them (at least I do). But the ferrules still have plenty of life in them.
With a grinder, you can keep on using those ferrules - just keep on grinding them down! I'm still using the same set of ferrules I started with this summer, and I have 800 kilometers on them, if not more. And I still have no plans to replace them any time soon.
If you're only occasionally rollerskiing, then diamond files will be much more economical.