Alignment Help
It depends on what type turn plates you have. I have an old set of Hunter turn plates I rebuilt that allow complete jounce and rebound, so the front end can be jacked up and set back down fine. It makes adjusting the cams much easier.
Most of the turn plates out there that are affordable enough for home use are just that, turn plates. They do not have a sliding component, just rotating. For those plates, “jouncing” the bumper will never fully settle the car. The plates have to slip for that to work.
The problem is that the wheels make contact with the plate/ground when the suspension is fully extended. At that point, the wheels have a ton of positive camber. As the the suspension sits down, the track width increases slightly and the camber changes with the decreasing ride height. But the tires are on the ground, and the resistance you get from the tires not sliding on the ground holds the suspension up. So unless you have it on slip plates in the front, you have roll the wheels to let the suspension settle. That’s why when you put the car on the ground after jacking it up it stays higher than the ride height has been set.
If you run skinny, hard front tires they may reduce that effect and make “jouncing” the suspension more effective because the tires may slide on the ground. If you run wide, soft front tires they’re not gonna slide, enhancing the ride height change and making the “jouncing” thing useless.
When I was taught alignment, the thing that helped me the most, was my mentor emphasizing
- A bicycle HAS + Caster .
Hope it helps someone else .
Yup. And a shopping cart wheel has negative caster. Which is why you want positive caster.
With the UCA you want to move the top of the spindle as far back as you can get it. So you adjust the front leg of the UCA so it moves away from the frame, pushing the ball joint backward. And you adjust the rear leg of the UCA so it moves toward the frame, pulling the ball joint back. That’s max caster.
Then you adjust the camber. If you don’t have enough negative camber, use the front adjuster to pull the ball joint back in a little. If you have too much negative camber, use the rear adjuster to push it out. Both adjusters should have been maxed out, so you only have one direction left to move anyway.