What's the cause of this kind of tyre damage? What's causing this type of damage to the tyre? It's a 25 x 622 tyre on a 13 x 622 rim. Tyre is a Schwalbe Active Line K-Guard. The tyre itself doesn't seem worn. ![Tyte](

Another possible cause is misadjusted rim brakes where the brake pad makes contact with the tire's sidewall.