Polyurethane bushes

[jonathon]

Sorry for the delay in this reply, here are the prices for the relevant bushes

Top trunnion......£1.70
Eye bolt bush.....£1.70
Rear shackle bush......£1.50
Van front shackle bush......£1.64
Axle saddle pad........£4.88

All prices are plus VAT and carriage.

These bushes are suitable for upgrading the suspension on standard or modified Minors. The front trunnion, eye bolt bushes are rated at 95. as these are subjected to the highest loading on the suspension.

[Peetee]

anything to firm up the soggy suspension on the Minor

Poly bushes won't actually firm the spring or shock response of your suspension. What they actually do is to reduce the free play in the suspension linkages. Any movements other than those described by the suspension as it compresses under load ie fore and aft and lateral are supressed by the bushes. if you imagine a car driving over a pothole, not only is the suspension compressed, but the front edge of the pothole submits a backward force on the suspension as the wheel hits it. This force is resisted by the eyebolt and lower suspension bushes. The firmer the bush the more the force is felt through the body of the car. Now you could be forgiven for believing fitting harder bushes would be a backward step. however when you consider that these unwanted movements create an adverse reaction in the steering and handling by displacing the suspension upright, you see that harder bushes have advantages too.

[bmcecosse]

Errr - well thanks for the simpletons guide PT !! I do have poly bushes all over my Mini already ! And I fancy the suspension rearward forces (including braking) are taken by the tie-rod - not by the eyebolt ! Do you do tie-rod bushes in Poly Jonathon - some think they are too stiff (on Minis) and can lead to breakages - if there the same feeling on Minors ?

[jonathon]

Yes the tie bar bushes are rated similar to the originals i.e blue bushes. The uprated bushes are coloured red. These colours only apply to Superflex. We view the original tie bar as the weak link in the front suspension, allowing too much flex,especially under hard braking. We have produced an uprated version almost twice the diameter of the original, its made from EN16 T and is adjustable on the car so the KPI and Caster angles can be set acurately, rather than the rather ambiguous method of the original. The amount of 'crush' on the bushes is set by the accurate machining of the tie bar, hence no more squashed up bushes.
The cost of the bushes is £2.12 plus VAT and carriage.

[Peetee]

by the tie-rod - not by the eyebolt !

Quite right eh-hem bit late in the day I'm afraid.

Errr - well thanks for the simpletons guide PT

Didn't intend to condescend, but the quote "soggy suspension" was rather misleading.

[bmcecosse]

Come on PT - it wobbles about all over the place ! Mine is certainly not 'soggy' up and down ways thanks to heavy oil in the dampers AND big thick telescopics. The damping is fantastic - but the wheels flap about on the 'soggy' rubber bushes ! Can't see the need for bigger diameter tie-rods - they are already massive compared to Mini ones ( and they have to cope with 80 bhp going through the front wheels !) - but adjustable is useful - I certainly have them on my Mini. Is the tie-rod bush cost for the standard blue ones - or for the harder red ones ?

[picky]

Im a bit confused about these new poly bushes... are they supposed to improve the comfort of the ride, or stiffen the suspension, which means you can go faster round corners??
Picky

[jonathon]

The principle reason for using poly or any other uprated bush, is to eliminate to a higher degree the amount of movement . Rubber bushes are probably the best compromise when both compliance and comfort are the overiding criteria. When a greater degree of control, i.e less movement is required then the ratio is changed, with less given to comfort and more to, less compliance.In this instance use poly bushes.On a pure race car then no bush will be used at all, and spherical rods become the norm. If its comfort you need use rubber, greater response and longevity fit poly bushes, and race spherical.

[Peetee]

The primary purpose of bushes in suspension is to reduce to a minimum the amount of vibration transmitted from the road wheels to the body of the car. Everything that links the wheels and suspension uprights to the body ie the top link, tie rod and torsion bar have bushes. The wheels have to move in specific directions in order for the car to remain in control when driven, the firmer the bush the more accurately the wheels move but the more vibration is transmitted. Rubber bushes were for many years the ideal compromise. However the material ages fast and many Minors have become sloppy over the years as the bushes collapse. Poly bushes have various stiffnesses to give improved handling but also have the advantage of being more compliant to vibration and longer lasting.