Production of the machine was initially complex and located across different parts of England, with the engines produced in Wolverhampton, frames in Manchester, while components and final assembly was at Burrage Grove, Plumstead. In late 1968 Plumstead works was subject to a Greater London Council compulsory purchase order, and closed in July 1969. With assistance of a Government subsidy, the assembly line was moved to North Way, Andover; with the Test Department in an aircraft hangar on Thruxton Airfield. Frame manufacturing was transferred to Wolverhampton, where a second production line produced about 80 complete machines each week. Components and complete engines and gearboxes were also shipped overnight, from Wolverhampton to the Andover assembly line.
The production racer, featuring an OHV tuned engine, front disk brake and was finished in bright yellow - known as the 'Yellow Peril'. In March to June 1970 the updated S called the 'Roadster' had the 750 cc OHV engine, low-level exhaust, upward angled silencers with reverse cones. September 1970 saw the introduction of the classic 'Fastback Mk2', which had alloy levers with modified stands and chain guards. The "Street Scrambler" and the "Hi Rider" were launched in May 1971, with the "Fastback Long Range" with increased petrol tank capacity from July 1971.
The "Combat" engine was introduced in January 1972 saw the appearance of the "Mk4 Fastback", updated "Roadster" and the "750 Interstate". The "Combat" delivered 65 brake horsepower (48 kW) at 6500 rpm with a 10:1 compression ratio, but the stressed 750 cc twin proved extremely unreliable, with main bearing failures and broken pistons common.
The 'Combat' engine combined with quality control problems gave the company a bad reputation, which was highly covered in the press. By the middle of 1972 BSA Triumph group were in serious financial trouble. The UK Government decided to bail the company out with a financial rescue package, providing it would agree to merge with Norton Villiers. Norton Villiers Triumph was duly formed and the new company got off to a shaky start.
The last of the 750 series, the MkV was produced from November 1972 to mid-1973 as a 1973 model and featured improved crank bearings and the standard grind camshaft. Compression was reduced to 9.4:1.
Mk2 850 cc. In January 1973 the "Mk.5 Fastback" was launched and the "Long Range" was discontinued, foreshadowing the first 850 cc machines launched in April 1973. The "Roadster", "Hi Rider" and the "Interstate" all began to use a new 828 cc. engine, which had similar power to the 750 cc models but were less stressed.
1973 also saw the start of development on a new machine with a monocoque pressed steel frame, that also included a 500 cc twin, stepped piston engine called the 'Wulf'. However, as the Norton Villiers Triumph company was again in serious financial problems, development of the 'Wulf' was dropped in favour of the rotary Wankel type engine inherited from BSA.
In late 1973 redundancy notices were issued at Andover, followed by a sit-in at the works. The Conservative Government withdrew the subsidy in early 1974, restored by the Labour party post the general election. NVT resultantly decided to concentrate production of the Commando at Wolverhampton and Small Heath, causing unrest at Meriden which resulted in a workers" sit in and stopping production at Small Heath. By the end of 1974 NVT had lost over £3 million.
However, the company still managed to produce new Commando models, with 1974 seeing the release of the Roadster based "JPN Replica" and the "Mk.2a Interstate".
Mk3 850 cc. The 850 cc MK3 Commando was launched in March 1975 and for the first time was fitted with an "electric starter" - better described as electric "assister", as it would soon drain the battery. The range of models was reduced to just two machines, the "Mk.3 Interstate" and the "Roadster", both with a left side gear change, right foot brake and rear disk brake to comply with United States vehicle regulations. The specification remained unchanged until October 1977 when the last machines were made, although few 'Roadster's were made in the end due to the higher cash sales value of the Interstate.
Source: Graces Guide