A Pelican Case is perfect for a bike because they are "Unbreakable, watertight, dustproof, chemical resistant and corrosion proof...just some of the features that Pelican™ offers and total protection for your equipment. The Pelican dry box is made of ultra-high-impact structural copolymer that makes it extremely durable. Its exclusive 1/4" (6.4 mm) neoprene o-ring and ABS latches seal perfectly and it includes an automatic purge valve for quick equalization after changes in atmospheric pressure. Your equipment can fit into the high-density foam of the case for total subjection and protection against impact, vibration or shock. This case is NATO codified and tested to IP-67 (Ingress Protection). You break it, Pelican replaces it... forever."
http://www.amazon.com/Pelican-Water-Tight-Protective-Pelicase/dp/B000EBMCHE/ref=sr_1_14?s=sporting-goods&ie=UTF8&qid=1391288855&sr=1-14&keywords=small+pelican+case (Case I used)
http://shimanocenters.blogspot.com/2009/11/nirve-classic-mens-cruiser-bike-product.html (my bike)
Step 1: Tools and Items Needed
Tools and Parts
-Big Crescent Wrench or a Bike Head Set Wrench
-Assorted Ratchets and Sockets
-Wrench for MountingNuts
-Screw Driver for Bolts
-Assorted Nuts and Bolts
You will also need mounting hardware to be able to mount from the wheels and headset.
http://www.amazon.com/Nirve-Basket-Mounting-Hardware-Black/dp/B000QFRSNG (This is what I used)