THE RUBBER-BUMPER B
While the V8 came and went, a second intended MGB successor, known internally as ADO21, also failed to make production. Styled by Harris Mann and Paul Hughes of the Austin-Morris design office in Longbridge, the ADO21 was a wedge-shaped, mid-engine coupe with fashionable “flying buttress” sail panels. It was to have had a De Dion rear suspension and a choice of three engines: the 1,275 cc (78 cu. in.) A-series four from the Mini Cooper 1275GT, the new 1,748 cc (107 cu. in.) E4, or the 2,227 cc (136) E6. The smaller engine would allow the ADO21 to succeed the Spridget and Triumph Spitfire, but the six-cylinder E-series engines would have made it a credible successor to the MGB and MGC as well. Had the car made it to production, it might well have been called the MGD.
British Leyland’s enthusiasm for the ADO21 gradually diminished throughout 1970. The main problem appears to have been cost. Although the ADO21 used or adapted many components from other Austin Morris products, it would probably have been significantly more expensive to build than the MGB. Moreover, British Leyland’s market research showed that the vital American market strongly preferred conventional engineering. The ADO21 was finally canceled in late December and the prototype was scrapped about a year later.
(Some sources suggest that the ADO21 lost an in-house competition with a Triumph design that later became the TR7, but author David Knowles says that was not the case. The TR7 did indeed emerge from a design contest between Austin-Morris and Triumph, but while the Austin-Morris entry — also styled by Harris Mann — was badged as an MG, it was not the ADO21, which had died months earlier. Roy Brocklehurst, who succeeded Syd Enever as MG’s chief engineer in 1971, felt that the ADO21 did influence the TR7, but its impact, if any, was stylistic rather than mechanical.)
With the collapse of the ADO21 project, the four-cylinder MGB soldiered on. If it had continued unmolested, that might not have been so bad, but the latest American safety standards made that impossible. Starting in 1973, U.S. regulations required bumpers capable of withstanding a 5 mph (8 km/h) frontal impact and a 2.5 mph (4 km/h) rear impact, increased the following year to 5 mph (8 km/h) both front and rear. By 1975, the bumpers also had to absorb that impact without any damage to the body structure or frame. It was an extremely challenging requirement, especially for cars that had been designed more than a decade before the standards were even conceived.
Since failure to meet the new requirements would force the withdrawal of the MGB from the American market, the engineers at Abingdon worked frantically to find alternatives. As a stopgap, early 1974 MGBs added comically large rubber overriders to the existing bumpers. These were replaced late in the year by completely new steel bumpers with conformal plastic covers to integrate them with the shape of the body. This was arguably a more satisfactory solution than the massive chrome battering rams of many contemporary Detroit cars, which would have been disastrous on the MGB. The new bumpers’ aesthetic impact probably would have been mitigated if they had been body-colored, like those of the later Porsche 924 and 928, but they were available only in flat black, which gave the B a somewhat unfinished appearance.
At the same time, the four-cylinder MGB was raised about 1.5 inches (38 mm) to comply with new U.S. bumper-height requirements. This wreaked havoc on the B’s center of gravity, compounded on roadsters by the deletion of the front anti-roll bar, apparently as a cost-saving measure. The result was substantial body lean and a much tipsier feel than earlier MGBs, only partially mitigated by the belated standardization of front and rear anti-roll bars in 1977.
The redesigned bumpers also contributed to the MGB’s burgeoning curb weight, which was beginning to approach that of the old MGC. That was bad enough for unrestricted British cars, but North American Bs had to be detuned significantly to meet federal emissions standards, losing their dual exhausts and trading their twin S.U.s for a single Zenith-Stromberg carburetor. Power ratings quietly disappeared from MG’s advertising and brochures.
While the motoring press averted its collective eyes, these various indignities had surprisingly little impact on the MGB’s popularity. Business was down from its early-seventies peak, but the B was still good for between 20,000 and 30,000 sales a year, comparable to its mid-sixties volume. The MGB had outlived several direct rivals and few of the ones that remained were in significantly better shape. The late “rubber-bumper” B had become a sort of aging diva — no longer as trim, pretty, or graceful as it had once been, but still sustained by the loyalty of its many fans.