20-10-2019, 09:19 PM
I note, on re-reading this thread, that it originally started out as an inquiry as to the advisability of altering the caster angle to make the car more stable. Somewhere on 'U Tube' there is a video of comparative driving tests on several pre-war Austins including a 10, 12/4 and an18/6, which I now cannot find. The commentator remarks (as I recall) that all the cars had very little self-centering characteristics because the caster angle was not very great. All the cars seemed stable at speed however, which , in the case of the 18, was about 70.
When I bought my first Austin Seven in the late '60s, all the front suspension and steering was shot and it was all over the road like a frightened rabbit. Overhauling everything in sight behind the front wheels cured the problem.
During the late seventies and early eighties, I had a special, built mostly out of bits I had acquired during ownership of my first one. This ran on standard suspension with a Girling front axle. This car was tuned and was capable of 70mph in a straight line. During the build, all the shackle pins, and all the steering gear was completely overhauled and, running on 4.50X17 tyres at (as I recall, as the car was probably not more than 6 to 7 cwt. all up) about 22psi, the car behaved itself very well indeed.
I am aware (from my days with the special) the important effect that tyre pressures have on handing. I replaced the tyres on my car shortly after buying it with 3.50 x 19 Mitas's and run them at 26psi front and rear. This appears perfectly satisfactory for a half ton car.
All the cars that I have ever driven with solid beam front axles tend to bump steer to a greater or lesser extend. My Series 3 Landrover does, as well as the Seven but you soon get used to allowing the car to pick its way over the lumps and bumps with a relaxed grip on the steering wheel.
I am lucky with my present saloon, inasmuch as it is an 'un-got-at' car, but I recently began to have handing problems beyond 40mph. Once again, the front suspension is all good and tight. I have the correctly handed radius rods (yes, after reading the comments in this thread I did check) and the only thing that I could find amiss was that the nearside track rod end had play in it. As I commented earlier, correcting this has not only sharpened the steering response, but has cured the car's waywardness (such as it was) at speed.
The RP, with its perpendicular architecture and narrow track, is never going to handle as well as a more modern car but, on the standard setup in well maintained condition, it behaves itself very well.
The moral of the tale is: if you are having handing problems,especially on a standard car, make sure that all the suspension and steering joints are in good order and lubricated and that the correct bits have been fitted and correct any faults found before playing around with the steering geometry. I have discovered that even a small amount of play somewhere can have a profound effect on the car's behaviour.
When I bought my first Austin Seven in the late '60s, all the front suspension and steering was shot and it was all over the road like a frightened rabbit. Overhauling everything in sight behind the front wheels cured the problem.
During the late seventies and early eighties, I had a special, built mostly out of bits I had acquired during ownership of my first one. This ran on standard suspension with a Girling front axle. This car was tuned and was capable of 70mph in a straight line. During the build, all the shackle pins, and all the steering gear was completely overhauled and, running on 4.50X17 tyres at (as I recall, as the car was probably not more than 6 to 7 cwt. all up) about 22psi, the car behaved itself very well indeed.
I am aware (from my days with the special) the important effect that tyre pressures have on handing. I replaced the tyres on my car shortly after buying it with 3.50 x 19 Mitas's and run them at 26psi front and rear. This appears perfectly satisfactory for a half ton car.
All the cars that I have ever driven with solid beam front axles tend to bump steer to a greater or lesser extend. My Series 3 Landrover does, as well as the Seven but you soon get used to allowing the car to pick its way over the lumps and bumps with a relaxed grip on the steering wheel.
I am lucky with my present saloon, inasmuch as it is an 'un-got-at' car, but I recently began to have handing problems beyond 40mph. Once again, the front suspension is all good and tight. I have the correctly handed radius rods (yes, after reading the comments in this thread I did check) and the only thing that I could find amiss was that the nearside track rod end had play in it. As I commented earlier, correcting this has not only sharpened the steering response, but has cured the car's waywardness (such as it was) at speed.
The RP, with its perpendicular architecture and narrow track, is never going to handle as well as a more modern car but, on the standard setup in well maintained condition, it behaves itself very well.
The moral of the tale is: if you are having handing problems,especially on a standard car, make sure that all the suspension and steering joints are in good order and lubricated and that the correct bits have been fitted and correct any faults found before playing around with the steering geometry. I have discovered that even a small amount of play somewhere can have a profound effect on the car's behaviour.