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Sway/ anti roll bar.
https://ausmini.com/forums/viewtopic.php?f=2&t=102571
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Author:  Steam [ Tue Jul 08, 2025 8:56 pm ]
Post subject:  Sway/ anti roll bar.

Firstly is a sway or anti roll bar of any benefit on a road car and what is its purpose and effects.
Secondly to identify what type. An angle iron frame bolted across the rear of the rear subframe and along each side member. The bar is attached to the frame with rubher mounts with, from what I can tell are rods attached to the bar and then the bottom of the hubs somehow. I tried to take photos but I will need to hoist the rear to get a good one.
Any ideas appreciated.

Author:  ausdino [ Tue Jul 08, 2025 10:08 pm ]
Post subject:  Re: Sway/ anti roll bar.

My first MK2 S had K-mac (hydrolastic) front and rear bars when I bought it in 1976, installed by previous owner (original owner). My current resto MK2 S did have holes drilled in the rear subframe for a rear bar, though not fitted. I am installing Selby dry suspension sway bars on this car, having made brackets for the rear arms per pics below. K-mac bar on original car had pressed steel brackets mounted on rear bump stop bolt, with links dropping down to bar. Use of a rear anti-roll bar increases roll stiffness, therefore helping reduce understeer apparently.

Author:  1071 S [ Tue Jul 08, 2025 10:51 pm ]
Post subject:  Re: Sway/ anti roll bar.

Dave, a “sway bar” (aka roll bar) is basically a torsion bar that transfers load diagonally across the car. Ie a rear bar transfers load (and so grip) from the outside rear wheel to the inside front wheel… which is why people usually fit a rear bar to Minis …. to load the inside front wheel to reduce understeer by increasing front end grip. Having a bar at each end just complicates things..

Most of them are round section ..like the set I bought at Selby’s Sydney MotorShow stand in ‘76 for my Golf. but there’s no law that says they have to be….

Get a case of beer and we can discuss the fine print.

Cheers, Ian

Author:  Steam [ Wed Jul 09, 2025 11:13 am ]
Post subject:  Re: Sway/ anti roll bar.

1071 S wrote:
Dave, a “sway bar” (aka roll bar) is basically a torsion bar that transfers load diagonally across the car. Ie a rear bar transfers load (and so grip) from the outside rear wheel to the inside front wheel… which is why people usually fit a rear bar to Minis …. to load the inside front wheel to reduce understeer by increasing front end grip. Having a bar at each end just complicates things..

Most of them are round section ..like the set I bought at Selby’s Sydney MotorShow stand in ‘76 for my Golf. but there’s no law that says they have to be….

Get a case of beer and we can discuss the fine print.

Cheers, Ian


Thanks for the great explanation, makes it really clear. I already have the beer. ;-)
Mine looks nothing like the ones ausdino has shown. Will try for better pics.

Author:  timmy201 [ Wed Jul 09, 2025 2:53 pm ]
Post subject:  Re: Sway/ anti roll bar.

Theoretically the sway bars don’t change the way the suspension works when you’re driving straight with no load on the suspension

When you add load, like around a corner the sway bar effectively adds stiffness like you’ve got a stiffer cone/spring

With a classic mini, normally a sway bar is added to the back end, and the stiffer effective suspension reduces the rear grip, in turn reducing the amount of understeer.

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