We have a sizable number of bikers among our customers - custom earplugs, custom IEMs, and Shure sleeves. Frankly, it depends on the size of your ears, but if you are wearing the SE425 successfully, the sleeve should work fine. Feel free to contact Sensaphonics directly with any questions. You might also want to check out some biker forums. I know the k1600forum.com (BMW) has had discussions.
7/17/14 at 9:50am