GD - CM Sport
 Back to brands list

GD D2-492-51-12
Photo ou archives : D. Ganneau

Capacity : 175
Model : CM Sport
Production : 1928 -
Category : (R) Street Bike


175 CM - 1929

A missed opportunity

Founding members Gherardo Ghirardi and Guido Dall 'Oglio left GD in 1925 to found a new marque, Dall'Oglio. After only building little two-stroke singles, it closed in 1928. GD's remaining founder-manager, Mario Ghirardi, was gradually losing his influence. For his future models, Ghirardi had to rely on designs produced at CM by Alfonso Drusiani and Mario Cavedagni. While Cavedagni had left GD at the end of 1925, he remained on good terms with his old boss.

New Regulations

Consequently, the 175 that GD launched in 1929 was a complete break from the previous productions of the marque, but was suited to the new Italian vehicle-licensing regulations established in 1928. These gave a great stimulus to the national motorcycle industry, for they raised the limit for lightweight bikes, which could be ridden without a license or road tax, from 125 to 175cc. Pedals were not required, there was no weight limit and the minimum age for riders was cut to 18.

Lack of Preparation

The GD 175 CM was a vertical single-cylinder two-stroke with siamesed intake ports and twin exhaust pipe. Three were entered in the International Six Days' Trial in 1929, but their lack of preparation did nothing for the marque's reputation or the model's commercial chances. Besides, the clients preferred the rival four-stroke models. Despite the arrival of designer Ubaldo Fangarezzi at GD in 1929, the company abandoned motorcycle production in 1931 and closed down in 1934.


Engine: 172cc (58x65mm) air-cooled single-cylinder; magneto ignition

Valves: two-stroke; ports controlled by piston skirt

Fuel System: carburetor

Transmission: 3-speed, chain final drive

Suspension: girder forks (front); rigid (rear)

Brakes: drum (front & rear)

Wheels: 3.00x25 inch (front & rear)

Weight: 220 lb

Maximum Speed: 50 mph

No longer capable of developing its own models, GD was compelled to rely on CM to design its new 175. It was the beginning of the end for a once great marque.

Motorcycle encyclopedia Moto Passion, realised by François-Marie Dumas, include almost 2000 photos presented with an exhaustive history of the motorcycles exhibited.

This unique collection has been realised with the participation of many specialists. With many thanks in particular to Yves Campion, Michael Dregni, Didier Ganneau, Jean Goyard, Helmut Krackowizer, Michel Montange, Christian Rey, Bernard Salvat, Mick Woollett, etc

One can order here

  • Original cards on paper (in french)
  • High resolution scans or original documents presented and signed with my name.

Please contact me at for conditions and copyright.

© Tous droits réservés
François-Marie Dumas

Accueil - Motos NOUGIER - Motos insolites - Motos japonaises - Unusual Motorcycles - Scooters du Monde - Motos Passion - Motos GILLET - Liens - Contact

Moto Collection - François-Marie Dumas

Valid XHTML 1.0 Transitional CSS Valide !

Mentions légales