Abstract: An adjustable bicycle is provided as well as an adjustable frame assembly and an adjustable steering column assembly. The frame assembly includes a seat tube, a head tube and a top tube assembly connecting the seat tube to the head tube. The top tube assembly includes a female tube and a male tube having a front attached to the head tube and the rear telescopically engaging with the female tube. The female tube telescopically slides within the first male tube. A locking mechanism fixes the position of the female tube relative to the male tube. The adjustable steering column assembly includes a steerer tube having a top and a bottom, the bottom being operatively engaged within the head tube. A telescopic tube having a bottom telescopically engages within the steerer tube. A steering column locking mechanism fixes the position of the telescopic tube within the steerer tube.