Frame for cycles, in particular for mountain bikes

A frame (10) for cycles (1), comprising:

• a seat tube (11) to the top end (11a) of which a saddle (12) is to be connected, and
• a front structure (14) and a rear structure (15) which have, in side view, a generally V-shaped configuration with the ends (14a, 14b;
• 15a, 15b) connected to the seat tube (11) and the respective vertices (14c, 5c) facing in opposite directions relative to the seat tube (11),
• wherein the front structure (14) and the rear structure (15) are substantially identical to one another and interchangeable and have respective first ends (14a, 15a) connected to an end portion (11a or 11b) of the seat tube (11) and respective second ends (14b, 15b) connected to a central or intermediate portion (11c) of the seat tube (11), whereby the frame (10) is adapted to assume selectively one of a plurality of different configurations by rotating one or both of said structures (14, 15) and connecting the first end (14a, 15a) of the or each rotated structure (14, 15) to the other end portion (11b or 11a) of the seat tube.