a roll or electrical tape
OR
a mitor saw (sorry bout spelling) and some pcv or abs pipe (pvc is harder and white, abs is softer and black) (65mm pvc fits OVER my wheels)

TIPS: if u go for the pipe option and it is not a tight fit, dont glue it on, wrap electrical tape around your wheels first.
if the pipe is a really close fit but wont quite get on, use some soap or mr. sheen (furniture polish), they stay wet for a while but when the dry the work like a really crappy glue, so u can still take them off.