Ducati MONSTER 821 Owner's Manual page 222

ABS DEVICE
Check that the front (1) and rear (2) phonic wheels are
clean.
Warning
Clogged reading slots would compromise
system proper operation. It is recommended to
disable ABS system in case of muddy road surface
because under this condition the system might be
subject to sudden failure.
Warning
Prolonged wheelies could deactivate the ABS
system.
1
2
Fig. 162
Fig. 163
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