It is reinforced in a way, because the lower tank bolts have long protrusions that are wider than the tank itself, which are hidden behind the sacrificial grey panels. Basically any impact energy applied to the side of the tank "should" go through these bolts and to the frame.

I too have seen the hose split by sharp rocks, particularly flints like we get here in Norfolk, but then again I've never had an issue. I do think its a little too easy to get a bit OCD about protection, you have to draw the line somewhere or you end up with a bike that weighs as much as a car and you'll never pick it up! There's also a lot of stuff on the market that masquerading as protection, but really is just bling as the parts they are quoted as protecting are either strong enough anyway or already protected (most such examples to be found in the TT catalogue!)

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