Colnago New Mexico road bicycle frame in Columbus steel

Vintage Colnago New Mexico road bicycle frame in Columbus steel

The Colnago New Mexico first version has 2 ribs in the horizontal top tube and the down tube. 
There are 2 ribs on both sides in the rear fork at the bottom. 
The New Mexico has Columbus Record tubes and is of better quality than the first version of the Mexico and Colnago Super.

The Story of the Colnago 'MEXICO' (all comments welcome)

Designed as a tribute to Eddy MERCKX and his world hour record in Mexico.
Launched at the end of 1972 with classic round tubes throughout, Columbus RECORD (the best and lightest tubeset available from Columbus at the time).
This is the main difference from a comparable Super from that time (made with Columbus SL tubes).
The chainstays are also said to be different (no dents on the Mexico, but there are on the Super).
Later, the frame tubes came with specific crimps: two in the top tube and two in the down tube (1983?); this is specific to the Mexico.
The second generation Mexico; some call this the "Nuovo Mexico."
Later, versions with two crimps in the top tube and four crimps in the down tube were released.
This version is actually the third generation and is called the "nuovo Mexico" by most.
The frame tubes here were partly Columbus SL and partly Columbus Record. In 1987, the fourth generation, the 'ESA' Mexico, was released, built with ESACOLNAGO SL tubing (developed by Columbus and Colnago).
It reportedly had four crimps in the top tube, and even six crimps in the down tube.
To simplify matters further, other versions of the Mexico were reportedly made, including a profiled seat tube, which was usually simply round.
Production of the Mexico (and also of the ESACOLNAGO frame tubes) ceased in the early 1990s – R.I.P.