I've had multiple versions of custom molded ear buds over the years. My experience is that...
If it's all silicone, i.e., no hard outside cover, at some point the wire catches on something and pulls everything right out of the silicone and that you have to send it in to get that fixed.
If it's all hard plastic, the wire never pulls out, but the plastic's lack of give starts to hurt my ears. After a couple days of touring, it hurts too much to continue use. Especially if your helmet puts any pressure anywhere near your ears.
If it's silicone on the inside with a hard shell on the outside, this type seems to be the sweet spot; the hard shell prevents pull out damage and the silicone prevents ear pain.
At the moment, I'm using Rider Buds (
https://www.indiegogo.com/projects/riderbuds-ultimate-earphones-for-motorcyclists#/) as an experiment. I can wear the Rider Buds longer than hard custom fitted, but not as long as soft custom, so I'm looking forward to getting fitted for custom again for the hard outside/soft inside version.
I've also used Plugfones (
https://www.plugfones.com/?gclid=CjwKCAjwg4-EBhBwEiwAzYAlsjkvsKahGNcIxnD3zVgRt7-8ODgw4s1xYf2ZNfIXH2LQnkpkk-HQdBoCG7gQAvD_BwE). They're an inexpensive option if your ears will tolerate them. Mine don't tolerate them for multi-day rides.
