Just curious, aren't you concerned that a car tire on front is going to amplify the steering effort
Ace, that is one of the several questions to be answered by doing this "car tire on the front TEST".
If I don't try it, I will never know the answer.
What I know right now is, I have a 120/70R-15 motorcycle tire on the front wheel, it appears to be a lower profile than just the 70....looks more like a 50 (in appearance), and it only gets worn in the middle half of the tread face, SO....mounting a 125/80R-18 Michelin X car tire, with a relatively flat tread face to begin with should give me close to double the tread On The Ground, it will raise the front of this bike approx. 1.25", and....we will see how it works.
The cost of this Michelin x tire was only $ 111.00 delivered to my place, and with the added cost of dismounting the motorcycle tire, then mounting this car tire to the wheel, I will be out less than $ 200.00 IF it doesn't work.
If it does work, then I will have found a much better tire for the front of this Burgy 650 when used in sidecar rig form.
In the past, I have had 93.14 % success rate on my tire experiments. Only 6.86 % failures, so I am willing to TRY, and if it works, great. If it doesn't work, then lesson learned.
Two Million Mile Rider
Exploring the World in Comfort
OOPS....correction....
I had presumed (never assume) that the 125R-15 Michelin X tire was a 125/80R-15.
NOPE...I was wrong (please don't hang me out to dry).
In inspecting all the data on the sidewalls, it turns out this tire is a 125/90R-15....GULP...which means these sidewalls are 28.5mm taller than the current 120/70R-15 motorcycle tire that is on the bike.
Oh well, just another part of the "experiment" 
Two Million Mile Rider
Exploring the World in Comfort