On The Pegs November 2018 - Volume 3 - Issue 11 | Page 78

On The Pegs
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On The Pegs
Vol. 3 Issue 11 - November 2018
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ment. Further names in the project were the constructor engineers Ruben Helmin,
Allan Kastberg and Egil Skoog.
A test protocol from the Royal Technical University, KTH, was performed by the
end of January in 1952. This engine reliability try-out was performed during vari-
ous conditions. Primus motor Carl Heimdahl in power source development was of
course present at KTH in Stockholm. This all happened before Olof Edlund came
to the engine laboratory. The tests were done in the cold room at the institution
for combustion technique with the aim to establish adequate greasing for clutch
and gearbox. Minus 30 degrees Celsius was set as a standard. It was an interesting
and satisfactory conclusion that the goods withstood this coldness without prob-
lems. It was noted that the throttle was sluggish and that neither the lighting nor
the signal worked at this freezing temperature. The Husqvarna people were thor-
ough in the development stage and it is no coincidence that the material was up
to standards. Their homework had been done right from the start.
two-ply tires, under-powered brakes, a frame that was not up to standards for
the potent engine and finally front forks that were more like rubber bands with
poor damping characteristics.
The following statements are an excerpt from the Silver Arrow book of instruc-
tions: ‘During the running-in period of this vehicle, the engine should always be
allowed to work easily, i.e. shift down over hills and heavy conditions. The work-
load on the motor should never be strained. The running-in period for engines
with hard-chromed cylinder-walls is 4-5,000 kilometres and you will not get full
performance before this distance. The abrasion in the cylinder is normally not
more than 0.004 millimetres over 10,000 kilometres of riding”.
One of the men behind the work was Carl Heimdahl. His background with
Husqvarna went way back as he had both ridden races for the factory as well as
being a test rider with deep knowledge in the mysteries of research and develop-
ment. Having an education as an engineer with a master’s degree, Carl Heimdahl
came to Husqvarna in the thirties with excellent technical knowledge. Another
engineer behind the scenes was Olof Edlund, who worked a lot for this invest-