This should probably be moved to General.. but anyways...
Since you're a bicyclist.. you probably want a backpack style carrying bag... i don't know of any notebook bavkpacks that are *that* protective... i have a nice Targus one... one thing you might look into is one of the solid aluminum briefcases with foam padding... then simply cary that in a backpack?? Falcon Northwest gives you an awesome aluminum carrying caes with the purchase of a notebook and you can have it custom painted to any color/images of your choice with automative-grade finishes.. NICE!!
Hope this helps..