4 replies to this topic

[spiguy]

Me again folks,

 

Getting lots of Q&A done today   Dunno if this is 'normal', hence the question, but if I jack up the front of the mini to do anything, then after I drop it back down, there is quite a bit of positive camber on the front wheels. After running up and down the road a bit, it goes back to normal. Is this common on minis, or does it indicate slop somewhere that shouldn't be there?  I have replaced balljoints recently so I know they are good, and when I had it all in bits to do front cones, the top and bottom arms felt fine with no sign of play. I know that the suspension will settle back down and that an increase in suspension height creates camber, but just bouncing the car to settle the suspension height doesn't get rid of it - it takes a wee drive to get rid of.

 

Cheers

Edited by carlukemini, 16 February 2015 - 05:03 PM.

[Tamworthbay]

It's normal, the tyres just need to move a bit to settle into the normal position.

[Dan]

Because the car has the type of suspension it has, in order for the car to drop on its wheels the track must get wider. The arms pivot directly across the car, not inline like they do at the rear. At the rear the wheels rotate as the car drops, providing the handbrake is off, to allow the suspension to drop. At the front the wheel rotation is not inline with the suspension travel, and the tyres can't slide sideways across the tarmac to allow the drop, so the car sits high until the wheels have tuned a bit and the tyres have scrubbed sideways a little as they turned. If you want to see a demonstration of it magnified, lift the rear of the car with the handbrake off and then apply it before dropping the car. It will sit high until the brake is released.

Edited by Dan, 16 February 2015 - 06:28 PM.

[spiguy]

Thanks guys. Dan, excellent explanation there - was like a light coming on as I read that, I hadn't thought properly about what was happening, but that makes perfect sense to me. Is this in any way a deliberate design in terms of the camber on both wheels during cornering? Just occurs to me that this design will result in the loaded wheel in a corner essentially gaining some negative camber, aiding tyre contact, but likewise the unloaded wheel will gain positive camber which will also aid tyre contact.

[Cooperman]

Yes, that is what unequal length wishbones are designed to achieve.

It is also why, when measuring & setting front camber it must be done after driving the car back and forwards a bit to 'settle' the suspension to the correct ride height.