It's very dependant on your ears and the eartip size you use. I personally would not bike with them, because as good as the passthrough audio is, there could be

It's very dependant on your ears and the eartip size you use. I personally would not bike with them, because as good as the passthrough audio is, there could be small differences in localizing sound that could really cause trouble on a bike. The passthrough is great, but not life or death situation great. Edit: this is for the Pros. The open non-pros seem like they would be safe for biking at lower volumes.