That's interesting. I have the medium and small moto fizz----the medium shown below is big.
I've seen a big one---it would have to go in the trunk of a car for me
It is monstrous.
The medium actually overwhelms my 950---works better on the KLR for packing too much "poo poo" !!
The medium would be way to big for your X-challenge.
Motofizz needs to rename their bags.
Large---for the guys who takes way too much "poo poo".
Medium--for the guy who takes too much "poo poo".
Small--for the guy who packs a little too much "poo poo".
I love the bags by the way---neatest things I've seen and come with a rain cover.
The expandable sides are the cats.