Hold off on purchasing that iPhone mount for your motorbike. In a new Apple Support post first seen by MacRumors, the tech giant has warned that high amplitude vibrations, "specifically those generated by high-power motorcycle engines" transmitted through handlebars, can damage its phones' cameras. As the publication notes, that damage can be permanent. A simple Google search will surface posts over the past few years by users whose cameras were ruined after they mounted their iPhone on their bike, mostly so they can use it for navigation.
While Apple didn't say why it's issuing a warning now, it did explain the reason why attaching the iPhone to a motorcycle can destroy its camera. The company said that the camera's optical image stabilization (OIS) and closed-loop autofocus (AF) features can be damaged by long-term exposure to high-amplitude vibrations. A camera's OIS makes it possible for a device's gyroscope to sense movement. In turn, the gyroscope changes its angle and the lens moves accordingly to prevent blur when you accidentally move while taking a photo.
Meanwhile with closed-loop AF, a phone's onboard magnetic sensors measure vibrations to compensate for the movement, so the lens can be positioned accurately. As MacRumor notes, all models since the iPhone 7 come with both features.
Thus, Apple says it's not recommended to attach iPhones to motorcycles with high-power or high-volume engines. For mopeds and scooters, you may want to buy a vibration-dampening mount to lessen the risk of damage — or simply just use another GPS device to make sure you don't ruin a device that costs hundreds to over a thousand dollars.