63 replies to this topic

[nicklouse]

Why would you want a beam axle? Independant rear is far better for handling, surley a rear beam set up is a step down

Nope. With the trailing arm the wheel angle is relative to the body roll.

A beam axel pivots about a "single point" ( easiest way to explain) so the body roll does not effect the wheels. So you can set the wheel angle to give the required angle for the tyres to give max grip or some slip angle or.... You can do much more.

A beam subframe replacement reduces weight. But you keep all that is good and bad of the subframe design but using coil overs rather than the Dounuts.

[Cooperman]

A beam axle is absolutely ideal for a smooth race rack where single rate high-rate springs will work very well indeed.

However, the vast majority of cars now use independent suspension all round to cope best with the varying road surfaces encountered on normal public roads.

Cars like the Ford Anglia and Cortina, from the same era as the Mini, were thought old-fashioned compared with the modern rubber cone suspension of the Mini and in fact later Fords, like the Granada, had independent suspension all round.

The issue with beam axles on road cars is that in a straight line and over bumps, the camber of the wheels is changing all the time due to the bumps not occurring on left & right wheel at the same time.

In my book, as a road car, there is no way of improving on the original rubber cone rising rate independent suspension all round, moderated by telescopic dampers which can be adjustable if so desired. The rear sub-frame is a brilliant way of reinforcing the rear structure as well.

[nicklouse]

In my book, as a road car, there is no way of improving on the original rubber cone rising rate independent suspension all round, moderated by telescopic dampers which can be adjustable if so desired. The rear sub-frame is a brilliant way of reinforcing the rear structure as well.

Not just your book.

The sping rate can be altered as well by either changing the profile of the lip in the trumpet or machining the donut. Or both.

Not really needed on the Mini but was done on some of the kit cars.

[Cooperman]

I seem to remember my old racing buddy Mo Mendham alluding to doing that, but my interest was always in rally Minis so I've been more interested in getting the best suspension travel and damping rate to cope with special stages on gravel and bumpy tarmac, for which beam axles would be far from ideal, structural strength being one of the advantages of the original sub-frame, seam welded and stiffened as necessary.

The problem with getting good road performance has always been lack of suspension travel on modern poor roads.  I have a road that I use for suspension testing and in my Cooper 'S' with it slightly raised and well set-up I can get no more than just over 60 mph on the long bumpy straight. In my Rover 214Si rally car I can get it to just over 80 and it still feels totally stable. I guess it's called 'the generation gap' where the Mini is an old and relatively slow car these days, but modern long-travel suspension, combined with superb springs just makes all the difference. But my Rover had a beam axle, of course.