I really like touring on my SD but am (was) frustrated by the lack of any functional luggage so I took matters into my own hands today. Since I already own a Givi E52 topcase for another bike, I just bought another mounting plate and bolted it directly to the passenger seat. I think it will work just fine.

I cut the center out for the lock assembly. (not pictured)


View from below.


On the bike.




From the back.






BK
USA

Is that a red chain or is rust? Nice job on the mount.

i hate to say this... looks ok but is poorly executed... whinced when i saw holes dilled in seat.

that being said spare seats over in the states are cheap

Please explain how and why you think this is "poorly executed". Sometimes simple is better no?

BK
USA

hmm, i like the idea but it looks like there would be a lot of torsional force on the seat (side to side) with a high center of gravity. the seat really isnt designed for that kind of stress. when a passenger is on board their weight is distributed through the foot pegs and they are not attached solidly to the seat, they can and do move as braking forces/acceleration is applied. ive thought about doing something like this myself but would rather attach it to the subframe somehow. there must be a way just have never looked into it seriously.
you may be fine, and let us know how it works out. id check the bottom of the seat from time to time for fatigue.

i just whinced when i saw holes drilled through the seat... and i agree with strat... attaching to sub frame would be best but not easy.

how does it move around and say 120km/h?

Well aren't you all a bunch of Nervous Nellys. ) that this will stand up to any loads put upon it, within reason.

The seat rests on the rubber pads along the subframe and is fairly stable with a relatively small load such as a loaded topcase on it. Sure it is loaded when accelerating and decelerating, but when just rolling along it is fine as it is almost completely out of the windblast. I do plan to occasionally look at the seat base for any signs of stress fracturing.

I have no problem being the guinea pig.....

BK
USA

ive seen more sercure things break upon heavy langing wheelies... i managed to break a set of exhaust pipes when i got very airbourne over a crest on my hypermotard

but other than that its great... although i think a tank bag could do most of that too.

as for VB... disgusting stuff. I am a fan of James Squire, James Boag, Blue Tongue, Red Back kosiosko and Crown Lagers... only aussie beers worth trying... and they are good

Givi doesn't want the liability. They have no way to know how and by what methods a person will mount their product so of course they will issue a blanket statement recommending against such actions. That doesn't mean other methods won't work.

My 02 Yamaha Vino scooter has a maximum capacity of 165lbs per Yamaha. It states that in the owners manual and on a sticker on the back. I weigh 190 lbs. and have ridden it for almost 8000 miles. It wheelies surprisingly well and has hauled up to 5 people (at the same time!) around the pits of many racetracks in the US with no ill effects.

The rear rack on my BMW has a max capacity of 10 kilos or some such low number. I routinely put twice that on it.

I can produce many more examples of my stupidity/luck but back to the GIVI on the SD.

I can grab the thing and torque it in all directions and it is secure. Sure it flexes and gives a bit but again, I have zero worries about tossing a weeks worth of stuff in there and heading out. Shoot, what are we looking at, 25lbs? The seat flexes and twists a bit with a 150lb. passenger. (yeah yeah yeah, some of their weight is on the footpegs etc. etc. but the majority is on on their behinds) The only real difference with the case would be the load under braking and again, the weight is overall so small that I can't see it being a problem. The only possible failure I can imagine is structure weakening of the plastic seat base over time due to the repeated torsional loading. I will keep an eye on the seat base I suppose.

I promise I will report back with any failures. (and eat my words if I have to!)

BK
not afraid

Not to say I'm a fan of drilling through the seat or even having a topbox in the first place, but as far as whether it will hold up or not, surely this isn't much different to strapping 40 litres of Kriega kit to your seat which a lot of us have done and plenty of others do on other bikes without batting an eyelid.