The Record Triumph
THE RECORD TRIUMPH
LEPPAN BRUFLODT TREMULIS
THE FELLOW WHO COINED “When you want something done right do it yourself,” passed on to posterity a rule that many men live by and with which many have achieved unparalleled success in one field or another. But we know of one man who would surely take you to task on this advice.
That man is Bob Leppan.
His twin-Triumph-engine streamliner Gyronaut X-l is the product of several good minds, and the argument in favor of this approach is hardly debatable. How
can you quarrel about the design of record-breaking motorcycles with a man who has the fastest machine on two wheels?
So much for the fundamental approach. Let’s see how the collective effort has attained the established goal.
The Gyronaut’s various components and systems are hung on a frame constructed of chrome-moly tubing with main members that are 2-1/2 inches in diameter. In execution, the design is not unlike modern aircraft. The rear wheel is mounted rigidly, and the front is hinged
but permitted only slight movement. This is only speculation, but this design feature probably damps out long-wave oscillations. Minimal, but essential, steering is handled by a gutted Triumph sprung hub. Because the hub does not rotate with the wheel, it can be used for mounting the vertical steering axis.
Gyronaut is powered with two 650cc Triumphs mounted in tandem, aft of the cockpit. By current go-fast standards the engines are rather mild. Modifications include H & C cams, Wertz pushrods, Web-
co valve springs, 10.5:1 Hepolite pistons and four 1-1/8-inch Amal 389s. Power output is about 110 bhp at 7,300 rpm. A single transmission is employed and contains standard ratio gears. Overall top gear is 1.89:1.
The cockpit of the X-l is sumptuous but functional. The tuck-and-roll upholstery would be most welcome should the vehicle suddenly, and rapidly, start changing its intended attitude.
The Gyronaut is scrupulously detailed and spotlessly clean, both inside and out,
The design is aesthetically pleasing and, judging by its performance, aerodynamically sound.
Leppan credits his success to the effort of his enthusiastic team, and, in particular, to builder Jim Bruflodt and envelope designer Alex Tremulis.
With the resources of this talented group behind him, Leppan’s mount for next year — a four-engine streamliner to break 300 mph — will probably eclipse the achievement of “old” X-l.
