bad knock on rear over the pot-holes

[axle]

Hi all
I can not get rid of the knock on the rear suspension I have tried different setting of the shocks . I have got the right set for the car from Dampertech.

This happens on bad pot holes, are the springs too short?

[flyerncle]

Could be hitting the bump stop on full deflection ie full travel if springs are too short.

[axle]

Hi both
Thanks for looking into this, the rear springs are 225lb, I have tried the dampers at 10 turns and 20 turns as for the tyres pressure they are about 20lb at the back. as for your comment about the inner rim hitting the tarmac should I see any mark?

I have tried the springs on various settings, but the knock is still there!

I do appreciate what you are saying about the weight of the car and the design compare to a rally car, it is really the pot hole on the country road casing me this madness.

Any more input into this will be great

[flyerncle]

Put tyre's up to 24/26 psi,I tried them low on race car I built and they try to roll off the rim in corners and squeal like hell .

[davedew]

The back end of mine knocks when there is a sudden drop in the road surface, pot holes, coming off of speed bumps etc. I am running 225lb springs as well but only 3 or 4 clicks on the dampers.

I think the knocking on mine is when the wheel drops down, ie the shock fully extends as they do suffer with a lack of droop in the suspension.

Maybe yours is similar.

[axle]

Thanks for your replies is this knocking noise more to do with metal contact with the rod inside the rear hub carriers?