u/HomeEleph

I got these magic speed 4 less than 4 months ago and have only done a little over 400km in them. However, the back of the heel has worn out completely and is rubbing painfully on my foot (see photo of shoes). Does anyone know why? I haven’t had this problem with any other shoes and normally wear them until the sole is looking worn out (over 500km). I had to stop and buy compeed blister plasters to complete a long training run. The length seems fine and is the same as previous shoes. How can I avoid this in the future? Thanks!