View source for MV Agusta 250 Monocilindrica Bialbero

{{Infobox motorcycle
| name             = MV Agusta 250 Monocilindrica Bialbero
| image            = MV_Agusta_250cc_No54_noBG.jpg
| alt              = Red Italian motorcycle with racing colors and the number “54” painted on the side
| caption          = MV Agusta 250 Monocilindrica Bialbero
| aka              =
| manufacturer     = [[MV Agusta]]
| parent_company   =
| production       = 1956–1959
| assembly         =
| predecessor      = [[MV Agusta 220 Bialbero]]
| successor        = [[MV Agusta 250 Bicilindrica]]
| class            = Racing motorcycle
| engine           = 248.2 cc [[Air cooling|air-cooled]], [[Single-cylinder engine|single-cylinder]] [[Overhead camshaft#Dual overhead camshaft|DOHC]] [[Four-stroke engine|four-stroke]]
| bore_stroke      = 72.6 mm × 60 mm
| compression      = 10:1
| top_speed        = {{convert|125|mph|km/h|abbr=on}}
| power            = {{convert|29|bhp|kW|abbr=on}} at 9800 rpm
| torque           =
| ignition         = [[Ignition coil|coil]]
| transmission     = [[Clutch#Wet vs. dry systems|Wet]] [[Clutch#Multiple plate clutch|multi-plate clutch]], 5 gears, [[chain drive]]
| frame            = [[Motorcycle frame#Full duplex cradle|double cradle]]
| suspension       = Front: [[telescopic fork]]s<br>Rear: [[swingarm]] with hydraulic [[shock absorber]]s
| brakes           = Front: 220 mm [[drum brake]]<br>Rear: 180 mm drum brake
| tires            = Front: 250 x 19<br>Rear 275 x 19
| rake_trail       =
| wheelbase        = 1230 mm
| length           =
| width            =
| height           =
| seat_height      =
| dry_weight       = 96 kg
| wet_weight       =
| fuel_capacity    =
| oil_capacity     =
| fuel_consumption =
| turning_radius   =
| range          =
| related          =
| sp               =
| footnotes        =  <ref name="MV Agusta Club Deutschland" />
}}
The '''MV Agusta 250 Monocilindrica Bialbero''' was a 250 cc factory racer manufactured by the [[Italy|Italian]] brand [[MV Agusta]] from 1956 to 1959. With this machine 15 GPs, 2 Driver Championships<ref name="motogp.com 1956" /><ref name="motogp.com 1958" /> and 2 manufacturers World Championships<ref name="Overwinningen" /> were won.
==Evolution==
MV Agusta had started participating in [[Grand Prix motorcycle racing|road racing]] with motorcycles in the late 1940s and initially concentrated on the 125 and 500 cc classes. [[Piero Remor]] built the [[MV Agusta 125 Bialbero|125 "Bialbero"]] ("twin-cam") for the 125 cc class. The machine was subsequently bored to 175 cc because that class was still very popular in Italy and almost all major brands built production racers for it. The 175 cc machine was further bored to slightly above 200cc, so that in 1955 it was possible to compete in the 250cc class with the [[MV Agusta 203 Bialbero]]. After one race the [[Engine displacement|capacity]] was further increased to 220cc. With that machine, [[Bill Lomas]] completed the [[1955 Grand Prix motorcycle racing season|1955 season]], finishing in third place in the World Championship.<ref>{{cite web |title=motogp.com · 250cc World Standing 1955 |url=http://www.motogp.com/en/Results+Statistics/1955/NAT/250cc/World+Standing |website=www.motogp.com |access-date=18 June 2019 |language=en}}</ref> MV Agusta also won the constructor's title.<ref name="Overwinningen">{{cite web |title=Overwinningen |url=https://www.mvagustaoldtimers.nl/?page_id=31 |website=www.mvagustaoldtimers.nl |publisher=MVagusta-Oldtimers |access-date=18 June 2019 |language=nl}}</ref> In 1956 the machine was finally further developed into a fully-fledged 250cc racer, but that was not possible by further boring of the cylinder, so the [[Stroke (engine)|stroke]] was increased from 56&nbsp;mm to 60&nbsp;mm.<ref name="MV Agusta Club Deutschland">{{cite web |title=MV Agusta Corse 203 - 220 - 250 Monocilindrica 1955-1959 |url=http://www.mv-agusta-club.de/MV%20Agusta/Modelle/MV%20Agusta%20Corse%20-%20203%20-%20220%20-%20250%20Monocilindrica.aspx |website=www.mv-agusta-club.de |publisher=MV Agusta Club Deutschland |access-date=18 June 2019 |language=de}}</ref>
==Technical==
The engine was an [[Air cooling|air-cooled]], [[Single-cylinder engine|single-cylinder]], [[four-stroke engine]] with [[Overhead camshaft#Dual overhead camshaft|double overhead camshafts]] (DOHC). The camshafts were driven by a [[gear train]]. The [[Poppet valve|valves]] were at an angle of 90° to each other and were closed by hairpin valve springs. The [[Bore (engine)|bore]] and [[Stroke (engine)|stroke]] were 72.6&nbsp;mm × 60&nbsp;mm, giving an [[engine displacement]] of 248.2 cc. A [[Dell'Orto]] SS 25 A [[carburetor]] was used.<ref name="MV Agusta Club Deutschland" />
A [[Clutch#Wet vs. dry systems|Wet]] [[Clutch#Multiple plate clutch|multi-plate]] was driven by gears from the [[crankshaft]]. The machine had five speeds. The rear wheel was driven by a [[Chain drive|chain]].<ref name="MV Agusta Club Deutschland" />
The MV Agusta had a [[Motorcycle frame#Full duplex cradle|double cradle frame]] that was constructed from [[41xx steel|chrome molybdenum]] tubes with a diameter of 25&nbsp;mm × 1.2&nbsp;mm. The [[Motorcycle fork|front fork]] was a [[telescopic fork]], and the rear suspension was [[swingarm]] with hydraulic [[shock absorber]]s.<ref name="MV Agusta Club Deutschland" />
==Results==
The machine was successful that year's [[1956 Grand Prix motorcycle racing season|championship]]: [[Carlo Ubbiali]] won five of the six GPs (in the [[1956 Ulster Grand Prix|Ulster Grand Prix]] he set the fastest lap but subsequently retired).{{sfn|Cook|1957}} Ubbiali was world champion and second in the championship was [[Luigi Taveri]] also riding an MV Agusta.<ref name="motogp.com 1956">{{cite web |title=motogp.com · 250cc World Standing 1956 |url=http://www.motogp.com/en/Results+Statistics/1956/NAT/250cc/World+Standing |website=www.motogp.com |access-date=18 June 2019 |language=en}}</ref> MV's dominance in the 250cc class was helped by lack of competition from other factories. [[Moto Guzzi]] (third with [[Enrico Lorenzetti]]) had already stopped developing the 250 Bialbero in 1955,{{sfn|Cook|1956}} [[NSU Motorenwerke|NSU]] (fifth with [[Horst Kassner]]) had withdrawn its factory team at the end of 1955 after the deaths of [[Rupert Hollaus]] and [[Gustav Baumm]],<ref>{{cite web |title=Rupert Hollaus |url=http://www.motorsportmemorial.org/focus.php?db=ms&n=1418 |website=www.motorsportmemorial.org |publisher=Motorsport Memorial |access-date=18 June 2019}}</ref> and Kassner rode with an NSU Sportmax production racer. [[Česká zbrojovka Strakonice|ČZ]] machines were by no means at the level of the Western brands, [[František Bartoš (motorcyclist)|František Bartoš]] was only twelfth.<ref name="motogp.com 1956" />
In 1957 the fortunes for MV Agusta changed. First, [[Mondial (motorcycle manufacturer)|Mondial]] appeared with the 250 Bialbero and two top drivers: [[Cecil Sandford]], who was the 1952 125 cc Champion,<ref>{{cite web |title=motogp.com · 125cc World Standing 1952 |url=http://www.motogp.com/en/Results+Statistics/1952/SPA/125cc/World+Standing |website=www.motogp.com |access-date=18 June 2019 |language=en |archive-date=24 June 2019 |archive-url=https://web.archive.org/web/20190624170047/http://www.motogp.com/en/Results+Statistics/1952/SPA/125cc/World+Standing |url-status=dead }}</ref> and brought experience to the team, and [[Tarquinio Provini]], who was only 23 years old but very talented. The season started well for MV Agusta: Carlo Ubbiali won the first Grand Prix at the [[Hockenheimring]] and his teammate [[Roberto Colombo (motorcyclist)|Roberto Colombo]] came in second. In the [[1957 Isle of Man TT|Lightweight TT]], Taveri and Colombo came in second and third behind Sandford, while Provini set the fastest lap. Ubbiali and Provini dropped out.<ref name="ReferenceB">''The Motor-Cycle'' dated 13 June 1957.</ref> In [[TT Circuit Assen|Assen]] the MVs did not start. Provini won convincingly, ahead of Sandford and [[Sammy Miller]]. Remarkably, MV Agusta dropped this race, Colombo was there, but only started in the 125cc class, in which he finished second. Roberto Colombo died following an accident during practice for [[Circuit de Spa-Francorchamps|Spa-Francorchamps]]  when he was using the [[MV Agusta 350 racers#MV Agusta 350 4C 1954-1964|MV Agusta 350 4C]].<ref>{{cite web |title=Roberto Colombo |url=http://www.motorsportmemorial.org/focus.php?db=ms&n=1422 |website=Motorsport Memorial |access-date=18 June 2019}}</ref> MV withdrew from the 250 cc class for the rest of the season. However, [[John Hartle]], on an experimental twin-cylinder MV Agusta still raced in Spa and won.<ref name="John Hartle career statistics">{{cite web |url=http://www.motogp.com/en/riders/profiles/John+Hartle |title=John Hartle career statistics |publisher=motogp.com |access-date=18 June 2019 }}</ref> Roberto Colombo was posthumously the best 250 cc MV driver that season. He finished fourth in the Championship, Ubbiali came fifth.<ref>{{cite web |title=motogp.com · 250cc World Standing 1957 |url=http://www.motogp.com/en/Results+Statistics/1957/NAT/250cc/World+Standing |website=www.motogp.com |access-date=18 June 2019 |language=en}}</ref>
The fall of 1957 proved be a turning point for world road racing championships. All major Italian brands (Mondial, Moto Guzzi, [[Gilera]] and MV Agusta) decided to withdraw en bloc from the World Championships. The costs of racing were huge and disproportionate to the sales.<ref>{{cite web |title=History of the MotoGP |url=https://www.devittinsurance.com/guides/motorcycle-racing/motogp/motogp-history/ |website=Devitt Insurance |date=2 February 2017 |access-date=18 June 2019}}</ref> For Moto Guzzi and Gilera this was especially so, because their income was solely from motorcycle sales. Mondial was able to make some money with transport tricycles and for Agusta, motorcycle production was still more a hobby than a profession. [[Domenico Agusta|Count Domenico Agusta]] reversed his decision and continued the racing activities. In [[1958 Grand Prix motorcycle racing season|1958]], MV Agusta was the only remaining top racing marque competing, so could engage the top drivers of the time: [[John Surtees]] and John Hartle in the 350 and 500 cc classes and Tarquinio Provini and Carlo Ubbiali in the 125 cc and 250 cc classes. Provini won four of the six 250 cc races that season and became a world champion by a huge margin,<ref name="motogp.com 1958">{{cite web |title=motogp.com · 250cc World Standing 1958 |url=http://www.motogp.com/en/Results+Statistics/1958/NAT/250cc/World+Standing |website=www.motogp.com |access-date=18 June 2019 |language=en}}</ref> and MV won the Constructors Championship.<ref name="Overwinningen" />
The machine was still used in [[1959 Grand Prix motorcycle racing season|1959]] by privateers, but the factory riders had the new MV Agusta 250 Bicilindrica, on which John Hartle had already won in Belgium in 1957.
==References==
{{reflist}}
==Bibliography==
* {{cite book |editor1-last=Cook |editor1-first=R.A.B. |title=Motor Cycling Sports Yearbook 1956 |date=1956 |publisher=Temple Press Ltd }}
* {{cite book |editor1-last=Cook |editor1-first=R.A.B. |title=Motor Cycling Sports Yearbook 1957 |date=1957 |publisher=Temple Press Ltd }}
{{MV Agusta}}
[[Category:MV Agusta motorcycles|250 Monocilindrica Bialbero]]
[[Category:Grand Prix motorcycles]]
[[Category:Motorcycles introduced in 1956]]
[[Category:Single-cylinder motorcycles]]