Mark C said:
Hi Al, how cofident do you feel the mounting system and boxes would hold up to an off/ slide.
Hard to say... as they have no parallel edges, they are very ridgid. If you just slid down the road, I suspect that all you'd get are scratches... They'd definately protect you from being pinned under the bike
I spent some time as I installed them trying to figure out what would go first in a crash, The bullets (2) are each held on by two small screws running through a sturdy SS piece, that would mean shearing off 4 or 8 screw diameters to get them to come off. It's possible that the blocks (on the cases) that the bullets insert into, could get pulled out of the cases, ripping a square of aluminum (backed by a stainless plate), about 3" on a side... I'm not sure of the shear stress specs for the case material...
As you can see in the images, the mounts go a long way to strengthening the bike's rear frame, that's a heafty block of aluminum clamped down the side there... (of course this may mean that the first point of frame breakage is lower on the sub-frame closer to the engine...)
One (perhaps) negative aspect of the whole system is they mount almost along a line at the top edge of the cases (the bullets are offset by an inch or two). The levering action (lifting up or pushing in on the bottom edge of the case) is resisted by a single (pretty thin) bent stainless plate (you can see it in the background of the image of the mounts), that slips over a hard point attached to the passenger foot-peg mount. (and a cross brace to the back of other case) If smashed inwards, or pried outwards with enough force, it could let go (by bending the plate or shearing off two machine screws),and the cases could then hing along the top edge, bending stuff because of the slight offset and force multipication theirin...
Having a fair bit of experience designing stuff just like this (for Oceanography)... and before that a career fixing Helicopters... without running any numbers of any kind, and with no experience with motorcycle crash dynamics... I think they are sturdy enough to take a fall on rough ground... but I have no intention of testing this "feeling"
Also, i feel that the design is very "recoverable" in the field, as the most likely breakage is some screws shearing off, bent aluminum (can be bashed out), or bent stainless plate (can be bent back)
Hope this makes sense,
Al...