I lived in PDC for 2 1/2 years. I am unsure that there is such animal as bike rental in PDC, since it is too freaking small of an area to justify a bike. There is no possible way to go anywhere interesting on a bike (Tulum, Chichen Itza, Coba, and Cancun are way too far away under vertical tropical sun) and in all probabilities you will get mugged if you are riding your bike on HWY 307. The roads to other visit points are way too remote and roads are way too dangerous even on a rental car.

Lay down the bike, drink, eat, snorkel, and bum around. No need for cycling.

If you feel vigorous enough, you may pay a ciclocab boy to pedal HIM around. You will make his day.