Aligment Maths Check.

[Chris01573]

Hi All, just trying to get the alignment somwhere handy, I am using the fishing line method creating two parallel lines a few inches from each side of the wheelbase with the line set at the centre of the wheels. I then measure the distance from the nylon line to the back and front edge of the rims and after adjustment am at this point. Have I calculated this correctly ? Alignment.png

[flying farmer]

Can't see any reason that shouldn't work.

When you have adjusted it, roll the car backwards and forwards a few yards to allow the suspension to settle. Toe in will cause the suspension to jack up both front and rear when travelling forwards, conversly it will drag the wheels apart and lower the car when travelling backwards which is why I try to get the alignment very close to parallel both front and rear

[Chris01573]

Thanks Neil, I can't work out if I am supposed to take difference between the two readings (leading edge and trailing edge of the rim) and treat this as the amount of toe (as I have shown above), or whether I am supposed to halve the difference and this is the amount of Toe ?

[flying farmer]

The tracking gauges I use give it as a total since each half is resting on a wheel rim.

I generally aim for parallel at the rear to a total of 1/16 inch maximum toe in at the front. I also ballast the driving seat to approximately my weight when setting up the rear suspension as I noticed uneven tyre wear on my TR when I tracked it up empty (this was 35 years ago), but the rear suspension is similar on the Stag

I found that the semi trailing arm suspension undergoes slight tracking changes as the suspension rises and falls.Obviously this happens less if you have uprated springs, but setting up the rear suspension is generally a one off unlike the front suspension where ball joint and bush changes over the years will require re-tracking. This makes it worth ballasting the car to its expected normal kerb weight before tracking the back end.

It is only really when you have worn a set of tyres out that you find how well you have done the job

[jbuckl]

After a new set of tyres & resetting tracking, I cannot help myself from running my hand over the tyre tread block.
Usually the blocks will lift and can be felt if there’s anything out.