Where to get tips for rollerski poles:
Call Jenex at 603-672-2600. Mention that you are from CSU. Order rollerski tips AND get a diamond hone for sharpening them.
Jenex also sells very reasonably priced poles. You can get them without any snow tips and just use them for rollerskiing if you want to avoid the work of changing tips spring and fall.
You can also buy poles and roller ski tips from Chris Li of the BikewaySource in Bedford (http://www.bikewaysource.com/) . Chris will mount them for you.
How to change pole tips:
Boil a pot of water on the stove. Put pole tip into the boiling water for about 30 seconds. Try to pull off pole tip (a pot holder or other hand protection highly recommended!!). If the tip doesn't come off then boil longer. If the tips are really stubborn then it may take two people - one pulling the pole and the other pulling the ferrule. (Additional note: Coach Alex suggests you can also use a hair dryer to remove tips if you don't have access to boiling water (i.e. if you're in a hotel or a college dorm or something) Turn the hairdryer on to "high" and slowly rotate the pole so that the hot air gets all sides. Then take off the tip as above.)
Once the old ferrule is off then you can put on the new roller ferrule. Dip the tip of the pole in the boiling water to heat up the remaining glue, then slide the new tip on. Put the pole tip on board on the floor and press down hard to make sure it goes all the way on. If the tip is at all loose then use a glue gun to add glue to the end of the shaft before putting on the tip. Be sure to use the yellow "hobby" glue and not the white glue. The yellow glue softens when heated so you can take the tips off again later.
Warning: most folks put the tips on facing backwards. It is counter-intuitive how they should go on. The tips need to point FORWARD. If you hold the tip and imagine it leaning forward you'll see why this works. Don't sweat it though, if you get it wrong I have a quick trick to rotate them in the field. (Heat the tips in the exhaust pipe of the car).
A CSU family has fun changing tips: