Karl also covers "wear and tear parts", as long as a sudden event causes the damage. The broken derailleur is insured just like the burst tire. Karl just doesn't insure ordinary wear and tear. If you want to replace a worn-out tube after a season just because you'd like a new one, Karl can't replace that for you. The same applies if the battery of your e-bike no longer provides the usual performance, without there being an external reason for it. The replacement cannot be submitted to Karl, that concerns the manufacturer's warranty.