3mm TOE IN
Seems to be the ideal setting for the Triking with standard width track.
An easy way to measure this is with two pieces of wood held against the wheel rims, projecting forward to give a clear area to measure in.
Take 2 pieces of straight wood (say 20x40mm) 1100 long. Let’s call them rods.
Mount each piece on 2 legs so that they stand at the centre line of the front wheels.
Glue 2 18mm spacers to the rods to stand them away from the tyres, ensuring they making contact with the wheel rims.
(The metal rods in picture are to keep it in contact with wheel rim, might need something heavier)
You can now measure across the rods with a non-drooping steel tape (or even another piece of wood that you can mark) at the front of the wheel, and again 18″ further forward.
Adjust the track rods to give a 3mm toe in setting. Remember to keep an eye on the steering wheel to keep it vertical when driving straight ahead.
After each adjustment, you MUST roll the car back and forward a bit to settle the tyres on the ground surface. Then re-check the setting.