Aerodynamics; Aeroacoustics - SCHUBERTH J1 Manual Del Usuario

D. THE HELMET

6. AERODYNAMICS

All SCHUBERTH motorcycle and racing helmets are developed and
optimised in SCHUBERTH's own wind tunnel under scientific, precisely
defined conditions. The J1 consequently generates practically no
upward lift and sits quietly in the air current. Combined with the minimal
draft of the visor, the well thought-out aerodynamics ensure that you
can ride even at higher speeds without difficulty. Further characteristic
features of the J1 are improved air resistance and high directional
stability.
Note:
Please note that the strong eddy currents that can occur at the
edges of the wind shadow on faired motorcycles owing to the
body panels can have a considerable effect on the aerodynamic
characteristics of a helmet.

7. AEROACOUSTICS

We have paid particular attention to ensuring the best possible
acoustic properties for the J1 without detracting from comfort. Various
features developed in SCHUBERTH's wind tunnel as well as the specific
choice of materials ensure that the helmet shows minimal draft and
make the helmet quieter*. It actually offers a significantly quieter riding
experience than most full-face helmets, giving you a more relaxed
journey – especially when riding for long periods.
A quiet helmet is characterised by low wind noise. Wind noise arises
through the turbulent swirl of the air flowing around the helmet. The
turbulence generates local pressure fluctuations, which you hear inside
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the helmet as noise (so-called pseudo noise). Only the wearer of the
helmet can hear this noise. With most motorcycles and helmets, this
wind noise covers up engine noise at speeds of 100 kph or more.
* Aeroacoustic values can vary according to the type of motorcycle, bodywork design,
riding position and body size.
Caution:
There is a possibility of slightly underestimating the actual road
speed due to the acoustic optimisation of the helmet and the
accompanying low wind noise, so don't rely on your sense of
hearing to judge road speed – check the speedometer.
Note:
Please note that on faired motorcycles strong eddy currents
occur at the edges of the wind shadow. This can considerably
reduce the aeroacoustic performance of the helmet. The fairing
of the motorcycle should be adjusted so that the departing
turbulence does not strike the bottom surface of the helmet.
Aeroacoustically non-critical area
Aeroacoustically critical area
Aeroacoustically non-critical area
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