the brakes on the newer bicycle the disk brakes do they need to be replaced or do they last forever?
hahahha sounds hilarious whatever ur imagination thinks.
You will have to replace the pads. Eventually also the disks if you use them a lot down hill and they over heat. If they are hydraulic you need to take care of that, fluid level, bleeding the line. The main thing with disk brakes is that they don't lock or they shouldn't if they are working properly. They also keep the heat away from the tire, although they may heat the grease of the bearings. They don't get wet of muddy, so they are more reliable on some circumstances.
Disc brakes wear just like the disc brakes on a car or motorcycle. Good disc brakes work very well, cheap ones don't work as well as good v-brakes.
