There is no specific value: if you live on the plains it can last up to 1000km while, in downhill use, it could last only 100km. It depends on how you use it and how much you use the brakes. Let's see how to understand the consumption of a pill.
BRAKE PADS
When the pad is new, the compound (material that comes into contact with the disc) is about 3mm thick. Naturally it is advisable to replace the brake pad before reaching the complete end of the compound, to avoid having no more material and braking iron on iron, therefore metal plate of the pad on the disc. Just one bike ride in this situation is enough to cause damage.
HOW CAN I SEE THE WEAR OF A MTB PADS?
The wear of a pad can be seen simply by eye: you have to look from above the caliper (or from below by lifting the bike in the case of ventilated pads that cover the view) and understand how much material there is on the pad. As mentioned previously, always change the pad with a slight margin in advance so as not to find yourself braking iron to iron.
Indirectly, when the pad is about to run out, the brake starts to become longer in stroke and, in the brake caliper, you start to see the pistons coming out.
FURTHER LINKS
How long do MTB brake discs last?
Here you can find other articles dedicated to maintenance -> Heading 365myarrangement
