1939/1940 BMW 328 Mille Miglia ‘Büegelfalte’ Fender Design

One aspect of the rapid evolution in automobile styling of the 1930s was shaping of fenders.  At the start of the decade, fenders typically were thin (in profile) and ogive-shaped, aft ends blending into running boards.  Then fender skirts appeared while fenders became more rounded in cross-section.  Profiles became teardrop-shaped.  Then some General Motors cars began featuring "suitcase" profiles.  Towards the end of the thirties aft ends of front fenders began creeping over front doors, while lurking in the background during the decade were "tank" bodies, where there weren't fenders at all -- wheel openings being cut into the body's sides.  These few cases mostly were racing cars.

By 1939 those creeping fenders finally touched forward edges of rear fenders in a few instances.  But not in "flow through" style as seen on American cars circa 1948-49.

Today's post features an attractive example: the rebodied 1937 BMW 328 Mille Miglia rennwagen -- racing roadster.  Some background is here:

"In autumn 1939, the car was dismantled at the BMW factory’s racing division in Milbertshofen before being extensively re-engineered and used as the basis for even more streamlined bodywork in preparation for the 1940 season and the Mille Miglia in particular.  To that end, BMW built both an aerodynamic coupé and this lightweight open roadster.

"Its design is credited to Wilhelm Kaiser, a very experienced member of BMW’s new design department, headed by chief stylist Wilhelm Meyerhuber.  A 1:10 scale model was tested in the wind tunnel of pioneering aerodynamicist Prof. Dr.-Ing. Wunibald Kamm, with a long, tapered tail that took advantage of the lowered engine and profile.

"The stunning bodywork was hand-formed by “Blasi” Huber in Ernst Loof’s racing department and made from a lightweight aluminium-magnesium alloy (Al MG 3-4) frequently used in high performance aircraft construction.  Aside from its low silhouette and flowing fenders, the prototype roadster’s fenders had a pronounced ridge along their tops. It resembled the crease in a pair of ironed trousers and gave the unique car the name it still carries today, Bügelfalte or “ironing crease.

"Its panels were formed over an armature of small diameter tubing, preceding the similar superleggera system patented by Carrozzeria Touring in Milan years later."

Note that Touring's Superleggera (super-light) construction was patented in 1936, according to this entry in Wikipedia.  That is why the BMW rennwagen coupe mentioned above, along with some Alfa Romeo racing coupes had bodywork by Touring.

Images of the 1939-1940 redesign are below, along with some photos providing an interesting twist to the story.

Gallery

1937/1940 BMW 328 Mille Miglia - RM Sotheby's Auctions photos
Very attractive.  Curvaceous, but not bloated, thanks to comparatively flat lower fender sides.  The two-segment BMW grille blends well.

Especially keep this image in mind because it shows the fender profiles.  Especially note the transition from front fender to rear.  The front fender and body seem to merge immediately in front of the rear fender.  There is a suggestion that the front fender has a small upwards curve at that point, but that might be an artifact of the curved door cutline.

Again, a very fine design with no obvious flaws.  Though the front and rear would be less pure if bumpers were added.

Overhead view highlighting those fender creases.

1939 Alfa Romeo 6C 2500 SS Cabriolet by Pinin Farina - Gooding Auctions photos
Mario Revelli, Conte di Beaumont has been credited with the design.  As best I can tell from limited Internet information, this design is slightly earlier than the BMW's.

Its fenders are almost identical with those on the BMW, allowance made for differing wheelbases.  There's even a slight flattening at the aft end of the front fender's curve.

The aft end is also similar to that of the BMW.  The main differences in the design are the grilles (less nice on the Alfa) and the cockpit zones.  The BMW was a racing car, the Alfa was a sports car, so seating and passenger requirements differed.

As mentioned, I am inclined to think that the Alfa Romeo was designed first, so its features were likely borrowed by the Germans.  And Revelli's long experience with aerodynamic design features makes the result consistent with his other work in the mid-late '30s.  That said, there remains the possibility of simultaneous invention due to the circumstances of the times, as in the apparent case of the Calculus by Isaac Newton  and Gottfried Leibniz.

1942 Buick 50 Super Convertible - Mecum Auctions photo
That kind of fender shape saw production on some of Buick's 1942 models, as shown here.

1949 Jaguar XK120 Roadster - unknown original photo source
A variation with a less-distinct rear fender is the classic XK120 Jaguar design.  Some other 1950-vintage sports cars had the fender concept discussed here.