AST, BC Racing solid topmount effects on camber/caster angle

[singlespeed]

Heres a clio AST solid topmount, just like the BC ones in their effect on the geometry. Instead of the bearing being central within the topmount, it is offset to the side, allowing the top of the strut to be off set from the original position.

If the ride height was the same as the standard suspension* moving the top mount will ...
1. As pictured here, this has moved the top of the strut backwards and so increased the caster. However, the strut hasn't moved inboard or outboard so camber will be the same as standard.

I'm half way between 1 and 2, so increased -ve camber and increased caster

2. The top of the strut has moved inboard, so negative camber will have increased. As the strut hasn't moved forwards or backwards, caster will be the same.

3. This has moved the top of the strut forwards and decreased the caster. However, the strut hasn't moved inboard or outboard so camber will be the same as standard.

4. The top of the strut has moved outboard, so negative camber will have decreased or maybe become positive (bad bad bad). As the strut hasn't moved forwards or backwards, caster will be the same.

*reducing ride height will exagerate the angles as the vertical offset between the lower ball joint and the topmount will still be the same, but the distance between them will be less... therefore increased angles

 

[maggi200]

Nice one Neil. I found this very helpful

 

[benmc]

Neil I fitted my solid mounts the other day and after giving the car a good blast out sounds like a constant frog croak at standstill now only quiet though .. Do you know what this is ? Also after the blast out but has gone now, there was a squeak/slight nock when setting off in first but no other gear, when the cars cooled its fine again would you by any chance know what this is too??

Thanks budd

 

[singlespeed]

Ben. Are your topmounts the Compbrake ones with no camber/caster adjustment? Are the mounts fully tightened so theres no movement?

 

[benmc]

Yea and yea to both Neil haha

 

[maggi200]

Callum, this thread is the useful one if you haven't found it yet

 

[mwalsh]

just a note, BC nuts are a lot better then AST ones. due to sending my AST to BC and missing the nut when it came back. BC sent me one of theres, doesn't come undone like the AST one. not sure if other users of AST mounts have had this problem. Nuts can be bought via pure motorsport