Wax does not just wear off the surface. A polyethylene base is porous, and the wax sits inside those pores. Once it is gone, snow and grit start working on the base material itself.
How to tell
- The base looks white or grey near the edges and at the nose — that is dried-out polyethylene, not dirt.
- The gear feels sticky on flats and you have to push.
- Run a fingernail over it: the base feels dry instead of leaving a faint waxy trace.
A sensible interval
Roughly every four to six riding days for an average recreational rider. Man-made snow is more abrasive than natural and eats wax faster than people expect — at resorts running snow guns, assume the shorter end. If you only ride a handful of days a season, a hot wax before and after is enough.
A hot wax with an iron lasts far longer than a rub-on, because it genuinely penetrates the pores. Rub-on wax is a stopgap — useful on a trip, not a substitute.