I've also wondered why you don't see hard cases for bicycles like you do for motorcycles.
I hated the ones on my BMW, they were clamshells and you couldn't really put much in them without removing them. There were plenty of other aftermarket options. They're all really too heavy-duty for bicycles, though.
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Genesis 49:16-17
"Well, well!" said Holmes, impatiently. "A good cyclist does not need a high road. The moor is intersected with paths and the moon is at the full."