All the above is good info. Trikes i'd avoid, it's like having a sidecar with no body on both sides, so you while you gain the stability you loose a lot of the carrying ability and all turns are "towards the chair". I followed a narrow Goldwing Trike to the Dragon and corners I'd be blatting through at 40-50, he was having to take at walking pace. He had no more luggage than a normal wing, so while he no doubt had his reasons for wanting something that didn't fall over, it didn't float my boat.
I should perhaps explain this better: A turn away from the chair transfers the weight onto the sidecar, so it's just like a car, too much speed you slide. With practice you can use the slide to your advantage, but at first snap the throttle shut and the chair will help you. A turn away from the sidecar lightens the sidecar wheel. Too fast and your nice stable outfit becomes a bike with a 700 kg pannier on one side
. This is known as flying the chair and is huge fun unless you didn't practice and go straight on into the oncoming traffic
Urals I can understand you avoiding. While they are perfect off road and the reverse gear has huge advanatges I know the 650's had components made of cheese and were assembled by drunken chimps (I threatened to put mine through the showroom window and got my cash back). The 750's are better but how better long term I don't know. The trick with a Ural is to only buy from totally first class experts who've fixed the problems and will support you.
The Ural chair is the most practical about and can be adapted to fit as on the BMW above, my Triumph and just about any bike with a proper frame. Oilhead BMW's get expensive as you need to buy lots to metalwork to add strength and rigidity to the bike. I had an R1100R, but wouldn't go that route again.
Unless you are totally minted, you'll need to ignore some of the advice you will get until you know about your own machine. Leading link forks are will reduce the steering loads, but you don't need them. I'm 5'7"/1.7m and not exactly fit (eat the wrong stuff, drink too much, rather partial to the odd cigar/pipe), but I can handle an 800 kg outfit on sand, mud, snow or the motorway for full days. Likewise, car tyres last longer but can introduce bad handling (my R1100R/Charnwood Meteor did lock to lock tank slappers at 85 mph
). The cost of new rims etc. will buy you a lot of old style bike tyres.
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