The Gender Divide
At almost all levels of competition, female endurance athletes compete separately from their male teammates. For a majority of these events, the men will compete for a longer period of time, and over a greater distance, than the women. They will compete for more sponsors, greater airtime, and more prize money than the women.
Media Coverage
It's just a given at this point: women's sports don't make it to air. While NBC airs many cycling races over the course of the year, there are few clips, if any, of a women's race among their collection, even though many races are run with both genders.
Competitive Opportunity
In most elite endurance events, men and women compete separately and for different race distances. In some cases, though, women have a significantly shorter season to go along with the shorter races. At the UCI WorldTour, there are 37 men's events, with 16 of them spanning multiple days. For the Women's WorldTour, there are only 20 events, five of which are multiple stages.
Prize Money and Sponsorships
While FIS and the IAAF have done well in equalizing the prize monies given out at major events, the UCI still has minimum payouts for races that are widely different between the two genders. At the highest level, the entirety of the prize money given out to the women's field is less than half of what the male winner of an event will receive.