Brifter cable wraps tightly around a small diameter drum and with its smaller diameter,
the brifter is a high stress area where cable breaks are common. The brake cable are
larger diameter and more of straight pull in the brifter, or a more gentle curve. Brake
cables will last years longer than brifter cables but an annual pull out of the cables and
exam is a good idea. The L shifter cable will last significantly longer than the R shifter
cable but much shorter time than the brake cables.