In an update to its Support forum, Apple warned users that exposing iPhones to high-amplitude vibrations, like those from high-power motorcycle engines, could cause problems with the device's cameras.
What's affected here are the camera's optical image stabilization (OIS) or closed-loop autofocus (AF) technology, which are designed to get rid of shaky shots.
OIS makes photos look less blurry even if the camera is in motion, while closed-loop AF makes focus adjustments if you suddenly move while snapping photos. iPhones 7 and up have at least one of these features, so if you have a newer model mounted on your bike, it could be at risk.
"The OIS and closed-loop AF systems in iPhone are designed for durability," Apple said. "However, as is the case with many consumer electronics that include systems like OIS, long-term direct exposure to high-amplitude vibrations within certain frequency ranges may degrade the performance of these systems and lead to reduced image quality for photos and videos."
This warning from Apple doesn't mean that your iPhone is at risk when you ride a motorcycle or are near them. The camera performance is only affected when you attach it to a bike. But if you're planning to mount your iPhone to a scooter or a smaller motorcycle, Apple recommends using a vibration dampening mount to keep your device safe.