Yamaha bikespeed-RS Instructions For The Installation And Description Of The Functions page 8

Bikespeed or the manufacturer of your pedelec cannot guarantee that
brakes, frame, chassis, tires, etc. are designed for the use of the tuning
part.
Before use, the more highly stressed components of the pedelec (e.g.,
frame, brakes, tires, bearings, and suspension, etc.) must be tuned by the
manufacturer or tested and approved by a suitable testing Centre (e.g.,
TÜV or Dekra). If the speed is doubled, it must be considered that the
acting forces are quadrupled. In accordance with EN 15194, it must
therefore be checked that the modified pedelec still meets the
requirements. It is to be assumed that the higher stress is permanently
given.
If a component of the pedelec cannot withstand the higher stress, it must
be upgraded by the manufacturer of the pedelec or by an authorized
specialist workshop, or the bikespeed-RS must not be installed.
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