This may be a stupid question! If the geo set-up is done with the cars weight on the wheels, which I'm pretty sure it is, then does the condition of the tyres have an impact on the accurate setting up? For example, the tyres are severely worn on one edge, geo is set up then new tyres are fitted, would the geo then be out??

 

The reference point is the wheels themselves so tyre condition doesn't matter.

(edit - for an initial geo)

 

I thought that tread depth could have an effect on the angle for camber?

 

It's not a stupid question, as MB said the wheel is the reference point for the readings, but if as you say your tyre's are severely worn on one edge, it will have an affect on a true GEO reading,

 

Not stupid. I though about this a long while back.

They would have to be very worn / weird tread pattern though to have an effect. With road geo settings I don't think it would be noticable, although a highly accurate machine might pick it up.

 

Good factual post near the bottom.

http://www.pistonheads.com/gassing/topic.asp?t=1163959

 

I agree in that situation where there was only a small amount of difference on the outer edge,

but in the case of badly worn tyre's as the OP stated it will make a difference, and as is often pointed out on this forum the S2000 is supposed to be sensitive to GEO, you should always have a GEO done after fitting new tyre's,

you would not believe how many people want a GEO on trashed tyre's, if you do set GEO on badly worn tyre's the car will never run true as the tyre's have scrubbed to the old wear,if your o/s tyre was worn on one edge more than your n/s then you do a geo you may feel a slight pull to one side after, or the steering wheel my be off centre due to the drag on the tyre from the previous uneven wear, some people mistake this as poor GEO job,

 

I've just re-read the OP.

If the tyres are badly worn, then you geo, then you put new ones on then i'd expect an issue. You are best off leaving alone.

What I wouldn't agree is that if you have good tyres then a geo, and the tyres wear out, you need another geo. That's overkill imo and I very much doubt it would be out of limits.

But i'd still say (imo) you would have to have some pretty odd wear (and therefore a dodgy geo) to have tyres worn enough to bugger up the geo excessively.

 

Sorry i must have missed something here, I didn't imply keep having GEO done, but in relation to the OP's question is it worth having GEO done on badly worn tyre's the answer is no, always have it done after fitting new one's, which I'm sure is what I said

 

Sorry, I was clarifying me, not you