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mushroom insert for front upright
novicebuilder - 19/4/14 at 05:43 PM

I have bought aluminium inserts from Rally design for my Sierra front uprights to accept a transit drag link in the place of the sierra strut. However it is not offset or tapered. So the transit drag link sits about 3mm proud of the mushroom insert top. I understand from the book that the hole in the top should be offset to aid the geometry and help self centring of the steering.

Should I buy some different ones which are tapered so it lies fully into insert and get ones that are offset? Or does this not really matter. I would be grateful for advice from this of you who have been here before! Thanks

davidimurray - 19/4/14 at 07:22 PM

You need offset ones with the hole at the front to give you caster for self centring.

garyt - 19/4/14 at 08:51 PM

Got a pair of angled offset ones new unused if interested
Gaz

britishtrident - 19/4/14 at 09:21 PM

The old chestnut is pulled out the fire once again.

*************** The fact is offset mushrooms have zero effect on castor. ***************

To change the caster the wishbone design or mounting position has to be altered.
Although they do change other aspects of steering geometry ie KPI and to some extent trail which can to some degree affect self centering centre.

britishtrident - 19/4/14 at 09:32 PM

quote:
Originally posted by davidimurray
You need offset ones with the hole at the front to give you caster for self centring.


Viewed in side elevation imaginary line joining the ball joint centres called the virtual king pin defines the caster angle.

Offset mushrooms only alter the angle of the suspension upright, offset mushrooms do not alter position of the ball joint centres so the angle of the virtual king pin remains the same.

novicebuilder - 21/4/14 at 09:27 PM

Thanks for the comments on the offset, but what about the lack of taper, is that OK?