It?s completely Sporadic and I have double checked to make sure it wasn?t my phone because any certified Apple charger I use charges my phone completely fine and I have no problems with them. Clearance between the bikes and vehicle, and ground clearance are great. Highly recommend them! The case adds minimal bulk but good overall protection. I wear a 9M and love the fit and length of the shoes are spot on my size. I think I did need to download a driver or something, but it hasnt impacted performance or changed my computer with downloads. I got a 12 . Threw the box away so I had to have it away to a friend instead of returning. The Kelli Flat doesnt cover up the sides of your feet as much, either. So customer is disappointed as they dont blend in with work uniformthey are like 2 different shoes as buckle on one side have to use last hole but not on other shoe, one shoe is very hard to do up, customer not happy as alot of money for faulty goods