Honda CB250 Nighthawk Owner's Manual page 118

For the best performance, you should
replace a tire before the tread depth at the
center reaches the following limits:
front
rear
If the wear indicators are visible, replace
the tire immediately as it is no longer safe.
Tire & Tube Repair
Refer to Saf ety Precautions
We strongly recommend that you replace,
not repair, any tire that is punctured or
damaged. A repaired tube will not have
the same reliability as a new one, and it
may fail while you are riding. And the tire
will have lower speed and performance
limits than a new one.
0.06 in (1.5 mm)
0.08 in (2.0 mm)
on page 54
A temporary repair can sometimes be
made in an emergency situation.
However, since a temporary repair may
not hold, you must ride very slowly,
preferably without any cargo or passenger,
and have the tire and tube replaced as soon
as possible.
(For more information on temporary
repairs, see
148 .)
.
If You Have a Flat Tire,
Servicing Your Honda
Tires
page
109