The company was established by Mario Mazzetti (1895-1964), formerly of GD, along with Alfonso Morini (b.1898) and two financiers in 1924. Alfonso Morini raced an MM himself and won a class in the 1927 Italian Grand Prix at Monza. The MM won numerous races during the years 1925 to 1929, at which point the 125cc class and ceased a 175 category introduced. A four-stroke 175cc machine was built for racing in this class, and this too was successful. At the time the 175 class was tax-free on the road, so it was also commercially succesful until 1933 when the rules changed, at which point MM introduced a 250cc road machine.
The 175 racers continued to impress for the remainder of the decade, winning world speed records and a 1/2 victory in the Italian Championship with riders Serafini and Bonazzi. Even Scuderia Ferrari campaigned with an MM.
A 350cc sidevalve machine was introduced and it too did well, winning major Italian endurance races in 1939 and 1940 and taking a medal in the 500 class of the International Six Day competition. This machine became the official Bologna police motorcycle (which it remained, apparently, until 1960).
A 500cc version was introduced in 1934, and both the 350 and 500cc SV machines were produced until 1950.
By 1939 the factory was producing around 400 motorcycles per annum and employed sixty people.
During the war they were forced to produce aeroplane parts and in 1943 the factory was destroyed by allied bombs - the war was not kind to MM, which had already suffered financially due to Mazzetti's vocal opposition to Mussolini.
Post-war the company produced a very fast 250 OHC model which sported rear suspension and Italy's first example of telescopic front forks, and this was soon joined by a 350 version. The 250 was as fast as the 500cc Gilera Saturno, whilst the 350 was good for almost 150 km/h.
By 1954 the 250 sported swingarm suspension with hydraulic dampers, a twin-loop cradle frame reminiscent of the featherbed, and a dual seat. There were few other motorcycles on Italian roads which could see it off, no matter the capacity.
Sadly, the market for such machines was fast shrinking, sales fell sharply, and despite the introduction of smaller, budget-priced 125cc motorcycles, MM closed the doors in 1957.
MM 350 Corsa 1938
1. In 1937, Alfonso Morini left MM and established his own company ( Moto Morini ) producing motorized tricycles (a motorcycle chassis, engine and front end with two wheels at the rear). MM has been referred to as being from the initials of Mazzetti & Morini, but this is not so.
2. Nunzia Manicardi has published a book on Mario Mazzetti.
3. An exhibition of the works of Mazzetti took place at Museo del Patrimonio Industriale in 2009/2010 which included sixteen of his motorcycles. Details here: Mario Mazzetti Exhibition
Sat Jan 09 2016
jennklym at Hotmail.com
1939 MM 500cc Italian racing bike
I inherited this bike, and am trying to find any information and the current value. I was not sure how to add to the forum or FB, so any help you can give would be appreciated! Thank you!!
Fri Jul 16 2010
pyoung<at>14engineering dot com
MM 1909 MM
I have posted an article about Mr Rodriguez on my site here: gottfried-rodriguez-around-the-world
I found a bit of info about him on the internet, but there isn't much that has been documented after he left the USA.
(This MM is actually by Marsh Metz, made in Brockton Massachussetts, unrelated to the Italian firm. Great story!)
Fri Oct 09 2009
1wetdog at tiscali.co.uk
mm motorcycle 350cc
any info on this machine as i am trying to restore one, call 07970 563935 or email
(see previous email below)
Thu Nov 13 2008
moto.mm.max at libero.it
I'm an italian likers of bikes MM and I buy all MM materials (bikes, engine, parts, ..). My blog is: motoblogmm.leonardo.it (404)
Tue Nov 11 2008
ittsuapizza at yahoo.co.jp
I'd like to know about .my father's BIKE which name is MM.250cc. built arround 1960. It's still possible to drive after the light tuning.
Please let me know how much worth for money.
The page on Classic Motorcycle Valuations may prove helpful.
Wed Oct 22 2008
peter at walde.at
Handbuch von Motor und gesamten Motorrad
Motto MM 350 C Bj 1934-1938
Habe eine motto MM Bj 1935-1938 restauriert
Habe jetzt probleme mit der Motoreistellung, Startet gut und lÃ¤uft im standgas auch gut. bei zunehmender gas aufnahme regelt der motor ab und hat keine leistung.
frage: Welcher vergaser ist fÃ¼r dieses modell am besten und haben sie unterlagen dafÃ¼r. haben sie auch dafÃ¼r unterlagen zur einstellung der ZÃ¼ndung
Mon Jun 25 2007
lammem at portup dot com
1909 MM motorcycle
MM motorcycle 1909
I have a postcard with Gottfried Rodriguez on the front on an MM motorcycle stating he rode it around the world but can find no info on either him or the cycle, any clues? The postcard is also autographed by him in Toledo, Ohio
Mon Jun 04 2007
jindrich.calta at seznam.cz
I'd like to identify the engine on the added photos. I have got a historic motorbike disjointed in parts and I don't know what is it. It was made about 1940, has 500ccm and there is logo MM on the engine. I'm going to construct it but I dont know how it looks.
I'm looking for some documents and photos of the old motorbikes made by M.M. Can you help me please or advise where can I get some information about M.M.?
Czech Republic, Havlickuv Brod
Thank you. I have found what I had been looking for. The model was made by MM in 1939.
I have recievd several photos from Mr. Giampaolo Tozzi from Bologna (His wifes' father made this motorcycles) and I'would like to share them.
Tue May 30 2006
1wetdog at tiscali.co.uk
MM 350cc Blackburn [Blackburne]
any information on this motorcycle would be nice in assisting with restoration has 350cc blackburn engine fitted very nice velose foot change on albion gear box , which model and which year would be a help thanks will post photos later
MM i think later to become moto morini
which year did MM fit a 350cc Blackburne engine in there bikes I have one and whish to restore it thanks
Wed Apr 05 2006
jamescastleuk at yahoo.co.uk
1950s MM 250 parts
MM 250 - 1950s
Hello there, I have a number of parts in excellent condition for an MM250 that a friend of mine rebuilt a decade ago and has since sold. I have photogaphed these scarce parts and lsited them on ebay and there is no interest which is surprising. I wonder if you could put me in touch with owner's clubs in the USA, UK and Italy. best wishes, James Castle
Tue Jan 31 2006
jindrich.calta at sezanm.cz
I have got an old motorbike disjointed in parts and I don't know what is it. It was made about 1940, has 500ccm and there is logo MM on the engine. I'd like to construct it but I dont know how it looks. I'd like to see some documents and photos of the old motorbikes made by M.M. Can you help me please and advise where can I get some information about M.M.?