Whilst the MTE group was still developing their BB9003 and 9004 prototypes, loco CC7121 smashed the world record for rail speed by reaching 243 km/h on a trial run on the PLM line between Dijon and Beaune. On March 28th and 29th 1955, after several months of tests, the CC7107 and BB9004 together reached 331 km/h on the line between Bordeaux and Hendaye in what was a new world record. The train was made up of three type DEV passenger coaches of 1946 which were sufficiently streamlined to allow low drag forces at high speed. During these high speed tests the ride of the CC7107 deteriorated following the considerable lateral forces which resulted from the destruction of the rubber silent-block bump stops.

As high speed current collection was not sufficiently understood at the time the pantograph head on CC7107 was dislodged after achieving the maximum speed, causing an impressive arc to be drawn. These tests resulted in a great deal of information being gathered which allowed very high speeds to be run in France - up to 200 km/h with the famous Mistral in 1967 then even higher with TGV in the 1970's.

However following the introduction of the BB9200's which ran at 160 km/h the CC7100's began to be overshadowed. The arrival of more classes of locos gradually confined them to freight trains. Still used sporadically to top and tail push-pull sets and particularly on freight, the CC7100 class was slowly reduced to five examples at the beginning of 2001. Locos CC7102, 7105, 7110, 7126 and 7140 then continued to work around Lyon, Dijon, Miramas and Narbonne on light duties.

Finally driven out by the BB 27000's , the withdrawal of the last locomotive took place in December 2001 after a career spanning 49 years.