Meldrew wrote:I used all sorts of hard panniers in my biking years and I can't remember having a single handling problem from them being fully loaded or mounted in the usual place. That includes the time I rode my BMW R65 from Andorra over the Pyrenees, up to Roscoff in Brittany for the ferry to Plymouth, and then back up to Cumbria in atrocious weather. The overloaded Krauser panniers were full of Le Creuset cast iron cookware I'd bought in Andorra and with all my other stuff the bike was so heavy both wheels touched the ground when it was on the main stand.
I once had a MZ ETZ 250 fitted with a set of genuine East German Pneumant hard panniers, being flat fronted and wide they had the aerodynamic qualities of a large breeze block fixed to either side of the bike.They didn't affect handling in any way but they robbed the MZ of acceleration when overtaking, cruising speed, and MPG. Though that wouldn't have bothered another MZ rider I used to know years ago.
He toured with so much kit he always used two sets of soft panniers on his MZ. The back end was like a panniers sandwich, one pair slung over the back seat, a load of camping stuff strapped on top of them, and another set of loaded panniers bungeed on top of them. He had even more stuff strapped to the rear carrier and in his tank bag, he was a regular at MZ camping weekends and rallies in the UK and Europe so 'handling' couldn't have been an issue for him either.
That other old chestnut that surfaces occasionally is 'top boxes affect handling'. They don't, or certainly haven't on any bike or scooter I've fitted them to. I've been using the Givi E55 for about 3 years now and it's a case of...

fill it, lock it, and forget about it.
Tankslappers on: TDM850, TDM900, BMW R100GS, CBR600, GSX750, ZX10, ZZr100, ZZR600, GPz600R, suggests you are wrong. ANY weight aft of the CG, high of the rotation point WILL have an effect on handling. It's a matter of fact. That you don't recognise it is only an indictment of your own faculties. I'm sorry, but that is the actuality of the situation. And having been part of a legal case where loading was a causation factor, the Law will agree with me as well.
I notice every kilo that is loaded aft of the rear wheel spindle, right up to the point that it causes a crash.
Weight at the back, high up, is a fucking disaster for motorcycle handling. and even worse for scooters which don't have a front end bias to start with.
No door is closed to an open mind.
Except a closed door, which a mind can't open, but even a stupid hand can.