I'm going to try and answer your question, and I am not putting any method for doing the 3-wheel alignment down. Like any tool, the proficiency of the operator plays a major role in the use of that equipment. For people like Lamonster, Squared Away, etc, who have been around since day one, their proficiency in using their equipment is second to none. They have data collected from back when the laser alignment system was introduced. To this day, the 3-wheel alignment is still done with reference cards, a laser level on a patented hub and tape measure. Other ways of doing the alignment comprised of taking measurements off the chassis, which in the alignment world is a no no; or building a jig to square up the front wheels (reverse trikes); or rear wheels (regular trikes). What I have done for the past two years uses none of the above, and I can see camber, caster, toe, and thrust angle live. I can make adjustment to that vehicle, live, and can verify my adjustment by sitting on my Spyder and looking at the change of the reading with the vehicle loaded, which is how it travels while on the road. The accuracy of this system is 0.01° for toe, 0.1° for camber and caster, and 0.01° for thrust angle. To get a straight steering wheel or handlebar when doing the alignment, you have to do a minimum of a thrust angle alignment with refence to the rear wheel for reverse trikes. My system will also do regular trikes, where you can see the rear individual toe, camber, and thrust angle. This will help the guys that ride regular trikes to get their vehicle handling better.
The system that I have repeats and you will also, most importantly, have a printed record of the before and after measurements. Record keeping is very, very important to this process. For the customer, dealers, and OEMs. It is nonexistent at this time. To this day, if you are not standing watching the alignment being performed, are you sure it's being done or done correctly? I have not done anywhere close to the volume of alignments Lamonster or Square Away have done, but what I can say is that there are about 60 printouts that single and dual riders have for their records showing what their 3 wheel vehicles look like; and after doing their alignment, I tell each of them not to trust what I have done and to allow me to prove that it was correct. I've had single riders &/or husbands and wives sit on their trikes so they could see the reading of the vehicle when weighted. This is why I have two specs; single rider and dual riders. With the level of accuracy of my system, those same people have told me of the changes in the way their Spyder handles, and that they are having to retrain themselves. Handling issues that they got used to and thought were normal are no longer there.
I don't know if the people that are doing the alignments are using low friction turnplates under the front wheels when making adjustments, but I do know they are not taking wheel and hub runout into consideration. The system has no way to compensate for it.
