The Bristol VR was originally designed for single-deck or double-deck bodywork. The design featured a longitudinal mounted engine set behind the rear offside wheels, rather than the more typical transverse layout. A choice of Gardner 6LX or 6LW engines or the Leyland O.600 engine were to be available. The transmission was a semi-automatic unit by Self-Changing Gears. Originally intended to be designated the Bristol N-type, the chassis became known as the Bristol VR, an abbreviation for Vertical Rear, a reference to the layout of the engine. Two lengths were available, 32ft 9in and 36ft, and these were designated VRS and VRL respectively. A drop-centre rear axle and low frame were employed to keep the height of the vehicle down.
Two prototypes were built in spring 1966, and were shown at the 1966 Earls Court Motor Show. This was the first show at which Bristol could exhibit since 1948, their products being available to the open market again. The prototypes had 80-seat bodies by ECW (Eastern Coach Works) and entered service with Central SMT and Bristol Omnibus.
In July 1967 Bristol introduced a new version, to be known as the VRT, with a more conventional transverse-engined layout. The chassis also became exclusively a double-decker. There was also a choice of two frame heights. The longitudinal mounted version remained, and became known as the VRL. However in July 1968 the British government introduced a grant intended to modernize the British bus fleets, and speed the introduction of one-man operation. The standard specification for the grant required a transverse rear-engined vehicle, with the result that few VRLs were produced.
The first production vehicles entered service with Eastern Scottish, a member of the Scottish Bus Group, in December 1968. Almost immediately problems were experienced with the transmission and overheating of the engine, problems similar to those experienced by early versions of the Leyland Atlantean and Daimler Fleetline. A large number of the initial production versions entered service with the Scottish Bus Group. Continued reliability issues resulted in 1973 in the exchange, on a one-to-one basis, of 91 Bristol VRTs from Central SMT, Eastern Scottish and Western SMT for front-engined Bristol Lodekka FLF6Gs from the National Bus Company.
A revision of the vehicle, the Series 2, was introduced in 1970, with changes including a the replacement of the single piece wrap around engine compartment door with a 3 piece version with a lift up rear section and swing out sides. In 1974 the Series 3 was introduced, with the main changes being to the engine compartment to keep in line with new noise legislation, the most visible change being to move the ventilation grills from alongside the engine to higher up, just below the top deck windows, connected to the engine compartment by trunking, plus the removal of the grilles from the rear engine compartment door. The short, lowheight version, became the standard vehicle for the National Bus Company. The VRT remained in production until 1981, by which time 4531 had been built. The Leyland Olympian, the successor to the VR, shared many similarities to the series 3 VR, although with updates such as air suspension.
Later versions of the VR proved reliable, and remain in service with many independent bus operators across the United Kingdom. A notable number have been exported to other countries. Some of the major bus companies still operate VRs, including Wilts & Dorset (all expected to be withdrawn in 2007), and until recently, First Devon & Cornwall Buses, who withdrew their last service VRs in December 2006 (although a few were retained for open top tourist services and special events.).
The Bristol VR was typically built with an ECW body, however, examples exist that carried bodies by Northern Counties, Alexander and East Lancs, with a few rare VRs having Willowbrook bodywork. The ECW body was distinctive for its rounded rear upper deck, a feature carried over from the ECW bodywork on the Bristol Lodekka and having its roots in ECW's styling on the Bristol K-type. The vehicles were typically constructed in the two heights set in the bus grant standards, 13 ft 8 in (4.17 m) and 14 ft 6 in (4.42 m). Other versions were built, including 13 ft 5 in (4.09 m) for City of Oxford Motor Services, and the 14 ft 2 in (4.32 m) height allowed under later versions of the grant specification along with the 13 ft 10 in (4.22 m) convertible open-toppers for companies such as Hants & Dorset, Southdown and Devon General.
The chassis code of a Bristol VR is very logical, and reveals a lot of information regarding the vehicle. The format is VRw/xxx/yyy, where w is the engine orientation (T or L: transverse or longitudinal, respectively. The prototype chassis carried an X here, i.e. VRX), xxx reflects the chassis details, and yyy the engine, e.g. VRT/SL3/6LXB is a short, low, Series 3 with a transverse Gardner 6LXB engine. The VRT/SL3/6LXB with ECW bodywork is the most common variant of the VR.
The chassis types are as follows:
* LH - Long/High; Series 1 (note: VRLs were only of the form VRL/LH)
* LH2 - Long/High; Series 2
* LL - Long/Low; Series 1; built primarily for Scottish Omnibus
* LL2 - Long/Low; Series 2; built primarily for Reading Transport
* LL3 - Long/Low; Series 3
* SL - Short/Low; Series 1
* SL2 - Short/Low; Series 2
* SL3 - Short/Low; Series 3
* 6LXB - Gardner 6LXB (Gearbox: Type RV90 5-speed semi-automatic)