Orbea R10 El Manual Del Propietario página 10

The helmet must sit firmly and level on your head. To
lower the front of the helmet to cover your forehead,
tighten the chin strap and loosen the rear strap. To raise
the front, loosen the chin strap and tighten the rear
strap. (Figure 8)
Fig.8
Correct Incorrect
To check the proper tension, put on the helmet and
fasten the buckle. Open your mouth. You should feel
the strap pulling against your chin.