They leave the family when they are about 14 years old, shortly after reaching sexual maturity, and then they have a long time before they can compete for mating with females. They go off and spend time with other young males until they grow up some more. A 14-year-old male will be less than half the size of an adult male. So he just bides his time for about 15 years, then he starts being sexually active. 

The penis of adult African bull elephant can reach lengths of four feet and weigh 60 pounds. The reproductive canal of an African elephant female is over eight feet long. Female elephants are only fertile two or three days during every four month estrus cycle. Males are only sexually active for short time when they are in musth. Often times the cycles of male and females don’t coincide