Today I finally revamped the comment notifications so that they work a bit better.
First, when you post a comment on a bike, you'll now be notified when someone replies to your comment.
Also, when you're the owner of a bike and someone posts a reply, you'll now get an improved email notification noting that there's a reply and linking directly to it on your bike's page.
These two changes should improve commenting and make it harder to miss replies. Let me know if you've got any feedback or suggestions to make the site work better. Cheers!