The document discusses valve float, which occurs at high engine speeds when the inertial forces on valve components become comparable to the elastic force of springs, preventing valves from closing properly. While desmo distribution systems avoid this issue and provide modest performance gains, their use has been limited mainly to racing due to greater complexity and cost compared to conventional valve systems commonly used in production motorcycles.

1. Conclucion
1
The most important is that you can work at a higher priority system to a
conventional distribution engine (and we know that the two most direct
ways to increase the power of an engine cylinder is climbing the same
speed or use the boost). At high speeds, the inertial forces generated
in the components (valves and springs) are very high and can become
the same order of magnitude as the elastic force produced by springs
in compression stage. The problem is served: the springs are not
capable of causing the closure of the valves. This phenomenon is
known as "valve float."
2
The benefits seem conclusive against the disadvantages, but the fact
is that, to date, its use (desmo distribution) has been limited practically
the competition and I say almost because some brands like Ducati
models they use in their street . In practice, the performance
improvement of the distribution compared to the conventional desmo
has been almost testimonial, in fact, the reason that the Ducati is
rather incorporate commercial technology.