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Founded by Mario Cavedagna and Oreste Drusiani1, the CM firm of Via Aglebert 22 Bologna developed a reputation for very reliable motorcycles well suited to competition work. The first machine was an OHV 175cc with a
three-speed Burman gearbox, with their first serious heavyweight appearing in 1933, an OHV 500cc model. This was followed by an OHC 250 in 1934. The year up until 1940 saw the range expanded with 350cc machines, and several of these remained in production throughout the war.
In 1936 Astra machines were entirely manufactured by CM Bologna, according to the page on Astra history2.
In the late 1930s the factory had around 40 employees, of whom 10 were apprentices.
Mario Cavedagni died on November 14, 1940 and was succeeded by his wife Irma Ginepri, who led the C.M. firm through the difficulties of the war years assisted by loyal collaborators. She saved the workers' jobs, and hid precious motorcycles, machinery and stock from the ravages of the fascists.
The firm was one of the few permitted to continue production during the war - their output was mainly motocarri and similar utility three-wheelers, but of course they maintained development of the machines they were passionate about whilst they awaited the end of the fascist curse.
As a result of the efforts of Irma Ginepri the company was well-placed to resume production once Mussolini had seen justice provided by those who reviled him, his long-suffering countrymen.
Production of pre-war models resumed in late 1945, and new range of machines was revealed in the early postwar period with the bevel-drive OHC four-speed Gheppio 250 of 1947
along with three OHV models; the Rampichino 250, and Sparviero and Grifone 500s, all with 4 speed gearboxes. 3
1949 saw the introduction of their first lightweight (motoleggera) 125cc two-stroke with rear suspension and telescopic forks.
This was followed in 1950 by a 500cc twin with a 180 degree crank.
The beautiful Francolini OHV 175 appeared in 1956 along with its less sporty Centauro sibling.
The final design was a 150cc two-stroke scooter which did not enter production. The Italian motorcycle industry was in turmoil with many factories closing. CM, unfortunately, was another victim.
The assets of the company were purchased by Mauro Negrini.
Engine: OHV twin-port vertical single cylinder with cast iron body and head. Bore 58.8, stroke 64.0. Cylinder capacity cc 173.7.
Ignition: magnet with Marelli
Carburettor: Dell'Orto (Original Amac)
Primary: chain drive protected by sheet crankcase
Multiple dry disk clutch
3-speed Burman, hand change
Chain drive transmission
Tubular chassis
CM 175 Turismo 1933
Engine: OHV twin-port vertical single with cast iron barrel and head. Bore 58.8, stroke 64.0. Cylinder capacity 173.7 cc.
Ignition: Magneti Marelli
Carburettor: Amac
Heavy duty lubrication lubrication with gear pump
Primary: chain drive
Multiple dry disk clutch
4-speed Burman, hand change
Final drive: Roller chain
Tyres: 3.00x19
Brakes: Expansion lateral
Electrical system: Lucas 6 Volt headlight, tail light, horn, dynamo, battery
Maximum speed km/h 85
CM 250 Lusso 1934
Engine: OHV twin-port vertical single with cast iron barrel and head. Bore 64.8, stroke 74.0 mm. Displacement 244cc.
Ignition: Magneti Marelli
Carburettor: Amal
Primary transmission: chain in alloy chaincase
Multiple disc clutch
4-speed Burman gearbox, hand change
Final Drive: Chain Drive
Frame: Cradle, steel
Tyres: 3.00x19
Brakes: Expansion lateral
Electrics: Lucas 6v dynamo, headlight, tail light, horn, battery
Maximum speed km/h 110
CM 250 Sport 1934
Engine: OHV twin-port vertical single with cast iron barrel and head. Bore 64.8, stroke 74.0 mm. Displacement 244.0 cc.
Ignition: Magneti Marelli
Amal carburetor
Dry sump lubrication
Primary: chain drive
Multiple dry disk clutch
Gearbox: 4-speed Burman, foot change
Final drive: chain
Chassis: tubular frame
Tyres: 3.00x19
Brakes: Expansion lateral
Electrical system with Marelli light, tail light, horn, dynamo, battery 6 Volt
Maximum speed km/h 115
CM 500 Lusso 1935
Engine: OHV twin-port vertical single with cast iron barrel and head. Bore 78.8, stroke 100.0 mm. Displacement 487.6 cc
Exhaust: dual exhaust, raised (high pipes)
Electrics: Bosch lighting and ignition
Dry sump lubrication
Primary: chain
drive Multiple disk clutch
4-speed Burman, foot change.
Tyres: 3.50x19
Brakes: Expansion lateral
Electrical system with Bosch headlight, tail light, horn, dynamo, ammeter, battery 6 Volt
Maximum speed 130 km/h
CM 500 Sport 1935
Engine: OHV twin-port vertical single with cast iron barrel and head. Bore 78.8, stroke 100.0. Displacement cc 487.6.
Ignition: Magneti Marelli
Carburettor: Dell'Orto
Dry sump lubrication
Primary: chain
Multiple disc clutch
4-speed Burman gearbox, foot shift
Tyres: 3.50x19
Brakes: Expansion lateral
Electrical system with headlight, tail light, horn, dynamo, ammeter, battery 6 Volt
Maximum speed km/h 135 -140
CM 350 Super Sport 1935
4-stroke vertical single cylinder engine with cast iron barrel and head. Bore 71.8, stroke 84.0, capacity cc 340.1. Valve Valve Distributed by Rods and Balancers
Ignition: Magneti Marelli
Carburettor: Dell'Orto
Dry Sump Lubrication
Primary: Chain transmission with alloy chaincase
Multiple Disc Clutch
4-speed Burman gearbox, foot shift
Chain Transmission
Tyres: 3.00x19
Brakes: Expansion lateral
Electrical system with Marelli light, tail light, horn, dynamo, battery 6 Volt
Maximum speed km/h 115
CM 250 SZ 1935
Engine: OHV vertical single with cast iron barrel and head, single exhaust port. Bore 54.8, stroke mm 74.0. Displacement cc 244.0.
Ignition: Magneti Marelli
Carburettor: Dell'Orto
Primary: chain drive under light alloy light oil seal
3-speed Burman gearbox, hand change
Chain-chain
Chassis: tubular frame
CM 350 Turismo 1935
4-stroke vertical single-cylinder engine with cast iron barrel and head. Bore 71.8. Stroke 84.0. Cylinder displacement cc 340.1. Valve Valve Distributed by Rods and Balancers
Ignition: Magneti Marelli
Carburettor: Amal
Gearbox: 4-speed Burman, foot change
Chain Transmission
Tyres: 3.00x19
Brakes: Expansion lateral
Electrical system with Lucas headlight, tail light, horn, dynamo, battery 6 Volt
Maximum speed km/h 110
CM 350 AB 1937
4-stroke vertical single cylinder engine with cast iron barrel and head. Bore 71.8, stroke 84.0, capacity cc 340.1. Valve Valve Distributed by Rods and Balancers
Ignition: Magneti Marelli
Carburettor: Dell'Orto
Primary: Chain Drive Under Lightweight Alloy Cover
Clutch: Multiple plate
Gearbox 4 - speed Burman, foot shift
Frame: Cradle, parallelogram fork, CM rear suspension with swingarm
Tyres: 3,25x19
Brakes: Expansion lateral
Electrical system with Marelli headlight, tail light, horn, dynamo, battery 6 Volt
Maximum speed km/h 115
Other models:
1931 175cc Type GD 70A Normale OHV.
1932 175cc Turismo OHV twin-port.
1933 175cc Turismo OHV single port 4 speed gearbox.
Enrico Ruffini and Antonio Campigotto have written a history of C.M., published by Giorgio Nada Editore. Moto Bolognesi C.M.
Notes 1. It is likely that CM also used Astra engines.
2. An article from Museo del Patrimonio Industriale speaks of the Laurenti brothers and Alfonso Drusiani, rather than his father Oreste Drusiani. Biblioteca Salaborsa has an article on Mondial which speaks of Oreste.
3. Gheppio 250 (Kestrel), Sparviero 500 (Sparrow Hawk), Grifone 500 (Griffon).
23-Nov-2018
k.engelen at gmail.com
Guzzi with CM motocarro 1943
Do hou have information about guzzi and CM working to make a motocarro ad the war?
Karel engelen
Joure netherlands
Can find no evidence of co-operation between the two marques. Ed.
Wed Jan 19 2011
cpabavon at aol.com
1955 francolino cm 175
hi we are in need of a wiring diagram for 1955 francolino cm175
massachusetts
Sat Aug 14 2010
abrantkoskimauricio<at>hotmaildot com moto cm 500cc raice
mauricio cm
ola eu tenho 1 moto CM 500 cc raice 1947 para venda 1 abraço
mauricio 18 . 97936599
brasil
Fri Dec 04 2009
lyndemotorsports at yahoodot com CM Three Wheeler motocarro
CM Motocarro
Still needing any service manuals or books
Vermont
Tue Jun 28 2005
cofranzk1 at virgilio.it CM italian motorcycles
devo restaurare una CM 125 del 49 cerco foto o letteratura
Wed Apr 20 2005
lyndemtc at sover.net cm motorcycles
I have a CM motorcycle (actually a three wheeler) and need any service
literature available.
Thanks
Stan
December 18, 2002
CM Motorcycles And Literature Wanted: I am interested in finding anything
on these bikes, especially the 125 and 250 two-strokes of the '50's. Also,
I have a limited selection of literature which I will gladly share with
others.
Bill Hooben, whh at post dot com
If you have a query about CM motorcycles please contact us