Bultaco 155 M2
The logical development of the Tralla 101 was to increase its cylinder capacity to 155cc by enlarging the cylinder bore. As stated in the advertising brochure at the time “The longest distances without becoming tired”, the improved torque at low revs was to increase the versatility of this model by allowing a passenger and even permitting the addition of a sidecar to the already prepared frame. The colour blue was used for the first time in this model was designated by Bultaco for touring and utilitarian models whilst red prevailed for its sports bikes.