Originally Posted by
kamtsa
This mirror should fit virtually on any bike due to its three degrees of freedom. Also good quality and very stable (no vibrations).
http://amzn.com/B0009R96YK
Ah yes my favourite mirror of all time. Unfortunately it doesn't fit with the new Trek FX bikes as their handlebars have a different design where you can't simply open up an end and plop it in.
I will try some of the other suggestions on this post. Cheers!