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McLain's Speed At Main & Houston

Above shows two frames from the Hughes film, 7 frames apart, showing Mclain passing in the foreground. The film was shot from the corner of Main & Houston. (The 'F' - frame - numbers are arbitrary, just the difference counts) . According to an analysis of the known rate at which the JFK limo. warning lights flash in the same movie (see picture below) ...

"President Kennedy's vehicle was equipped with two bright red alternately flashing light signals mounted on the front bumper of the Lincoln Continental which, according to Ford Motor Company, flashed alternately for .41 sec/sec each, i.e., in 1 second both lights would flash "on" 2.439 (.41 sec "on", .41 sec "off", with the remaining .18 seconds divided into two transition sequences of .09 second between illumination and extinction, resulting in .50 sec total "on" time, with the midway point in transition time (t*time) .09 seconds, considered as beginning and end of "on"-time... From the number of illuminated frames observed in the Hughes Film we estimate that Hughes' 8 mm. camera operated at 17.073 fps. (.41 sec = 7 frames, 1 sec = x frames; therefore, 1 sec = 17.073). This was 1.227 frames per second slower than Zapruder's camera by the FBI 18.3 fps estimate, "

... the frame rate of the film is 17.073 fps.

The length of the bike is about 2.21 meters. McClain covers this distance in 7 X 1/17.073 secs.

This gives a speed of 12.08 mph.

See also this sidebar on the question of the movie speed

Above is a sideview of Bobby Hargis, minutes after the assassination.

"Judging from the tank emblem it is a 1963-1964 FL or FLH. The 1964 FL's were introduced in August 1963."
"OK, possibly a 1963 Model FL." "Early 60's FL." (comments on the picture from the newsgroup

Hargis's bike seems to be a 64-FL DuoGlide. (The 64 was actually introduced in 63).
McLain's bike appears identical, in all pictures I can find. The bike is 7.61 feet ( 2.21metres) long.

"Two Milwaukee officers with brand new 1962 HD bikes, a DUOGLIDE....."

"The final stop of the day is the "Boot Hill Saloon", "Across from the Cemetery". Here I meet Steve who tells me he has the only 1964-FL Dallas Police bike, in circulation that was behind President Kennedys' limo that fateful day, and get this, he's only asking $85,000 for a piece of American history.."

In reference to this bike, it is interesting to note that: "A "real" motorcycle, for these people, can be nothing less than the biggest, most powerful model Harley-Davidson has to offer " - yes, they are talking about the Duo-Glide FLH .

The Duo-Glide FLH is Harley-Davidson's ultra-plus-ultra model for the heavyweight fancier, and to get a full understanding of just what it is that attracts so many road-riders to the H-D banner, we were furnished one of these machines for a road test. It was obvious (to us, at least) that the makers of the FLH had not concerned themselves too much with the usual design goals of reducing size and weight - which is no more than reasonable, considering that those are precisely the qualities that the customers want. The FLH has a 61-inch wheelbase (substantially more than has been found necessary on even the largest of foreign-built motorcycles)

Gary Mack, Curator, Sixth Floor Museum at Dealey Plaza


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