I think we can say the goal is to reduce trail and retain the stock angle (ride height) lengthening the wheel base by changing fork angle is going to change the lever angle compressing the front spring, which is why I liked this plus I personally have less than $300 in it in parts and powder coating,the welder and I collaborate but neither of us knew much about sidecars, allowing me the rear wheel purchase.
I have only ridden 4 sidecars in my brief career a Ural at a dealer demo, my 83 wing/ural with Steerite, Claudes Red Baron and mine, Claude liked it thought it worked as well as his, but he liked my gsa gearing open exhaust and unrestricted airbox and was pretty impressed with the whole thing, so his opinion may be biased.
I couldn't tell any difference in the way they handled except his sat lower not being a gsa and had the regular 1150gs single plug, I'm a little lean a little plugged up blues, which we worked on.
I'd personally like to try leading links but I don't want to pay for them.
If I started over I'd use a R1100 it's lower overall,geared lower is just as easy to warm up a bit and cheaper to start with, or an r1150r trying to get the weight lower to the ground.I think I remember you scaled yours around 850 and I'd bet mines even heavier.If I didn't mind going to BMW rallies without a bike mine would be a Mini Cooper.DB
Patience: A minor form of despair disguised as a virture.