A girl singing on a bicycle. Other cyclist in mask doing stunts. Any knows the title?

best guess is that its:
whats a girl to do
by bat for lashes.
http://www.youtube.com/watch?v=n1wnOUH2j...

As far as music video's go, I remember a video where a girl was riding a bike singing. Recent, relatively.

Corrinne Bailey Rae - Put Your Record On

I'm not sure about the spelling for Corrinne, but try searching the video and see if that's not the one.

=]

Hope you find it!