Karrueche Tran Bikini Racing in Cancun

RED ALERT!! Karrueche Tran's got major wheels in the sand ... and the alert is necessary because she showed off her speed while rocking a very small bikini that was hanging on for its life.

Karrueche's in Cancun with a friend, and the ladies decided to go head-to-head in a race on the beach. Again, ZERO tracksuits were worn during this athletic competition ... which is exactly why you should start clicking through the gallery.