Yamaha TT-R125(P) Owner's Service Manual page 418

REAR WHEEL AND REAR BRAKE
5 - 27
NOTE:
The bending value is shown by one half of the
dial gauge reading.
WARNING
Do not attempt to straighten a bent axle.
Drum brake
1. Inspect:
Brake shoe lining surface
Glazed areas
Use coarse sand paper.
NOTE:
After polishing, wipe the polished particles with
a cloth.
2. Measure:
Brake shoe lining thickness a
Out of specification
Brake shoe lining thickness:
Standard
4.0 mm
(0.16 in)
NOTE:
Replace the brake shoes and springs as a set
if either is worn to the limit.
3. Measure:
Brake drum inside diameter a
Out of specification
Brake drum inside diameter:
Standard
110 mm
(4.33 in)
CHAS
Polish.
Replace.
<Limit>
2.0 mm
(0.08 in)
Replace.
<Limit>
111 mm
(4.37 in)