Carrying a NEX 5n (storage and usage) while cycling

Take a look at OPTech for a basic neoprene cover for the NEX...

http://optechusa.com/pouches/soft-pouch-digital-d-series.html

I think I have the midsize offset or the M4/3 model, but it fits well on my NEX 7.

A sling type backpack would be the quickest access on the go:

http://www.kata-bags.us/lightri-310-dl-for-mirrorless-camera-or-handycam

You'll probably need a cross-strap for more stability. Here's a video example of how attached to a timbuk2 messenger (skip to 1min mark):

https://www.youtube.com/watch?v=CPidjsVsWkw

And a generic cross-strap, if you don't have some spare webbing:

http://www.rickshawbags.com/zero-cross-strap.html

If you're okay with just the strap these seem interesting:

http://joby.com/camera-straps/ultrafit-sling-strap-for-men/

http://www.carryspeed.com/products/ds-3-camera-sling-strap-with-d-1-wide-platform-ballhead

If you wear a backpack take a look at this basic clip:

http://peakdesignltd.com/capture/

With that said, I use the Peak Design Capture clip attached to a 5.11 sling bag converted with a padded camera insert.  On the go, I attach the camera to the strap via the clip.  For general carrying, I put the camera in the bag along with lenses and tripod / monopod.

Sorry for the long post... I've tried a lot of things.

Hope that helps!