The German automaker says it found the issue during its ongoing durability testing, and that it's very unlikely they would detach in real-world driving.
There are many pros and cons of using e-bikes over mopeds and vice versa. E-bikes aren't as heavily regulated, but mopeds usually have better performance.
To make an air-cooled Porsche 911 rev to 12,000 rpm, one of the mods you'll need is a lighter 24-valve cylinder head, like the one built by Swindon Powertrain.