The present paper offers the chance to experimentally measure, for the first time, the internal
tire strain by optical fiber sensors during the tire rolling in real operating conditions. The phenomena
that take place during the tire rolling are in fact far from being completely understood. Despite several
models available in the technical literature, there is not a correspondently large set of experimental
observations. The paper includes the detailed description of the new multi-sensing technology for an
ongoing vehicle measurement, which the research group has developed in the context of the project
OPTYRE. The experimental apparatus is mainly based on the use of optical fibers with embedded
Fiber Bragg Gratings sensors for the acquisition of the circumferential tire strain. Other sensors are
also installed on the tire, such as a phonic wheel, a uniaxial accelerometer, and a dynamic temperature
sensor. The acquired information is used as input variables in dedicated algorithms that allow the
identification of key parameters, such as the dynamic contact patch, instantaneous dissipation and
instantaneous grip. The OPTYRE project brings a contribution into the field of experimental grip
monitoring of wheeled vehicles, with implications both on passive and active safety characteristics of
cars and motorbikes