^^^
Thanks for the explanation, the fact you can reproduce it on particular roads, is of specific interest.
Quote:
Originally Posted by Scudder
If you experienced it you would have no doubt. These are not people nit-picking. This is a serious issue.
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Which begs the question have any of BMW's Technical guys (I don't mean from the dealers but the 'Area Technical Managers' as we have for the UK) sat besides drivers who can reproduce it on demand.
Trying to get inside this (as an engineering designer/problem solver), I do feel there is something feeding back from the road, which when meeting specific conditions, likely sets up some 'odd beat' harmonics which the working parameters of the EPS can't filter out.
The fact that a poster has mentioned road force balancing reducing the problem, and another that the sport setting also reducing the vibration level, does point at the way any interference factors are damped out. Seems some combinations of interference can still get through.
My own experience in an example of the 328i, for 80 or so miles over all kinds of surfaces, did not give me any vibrations or shake, and I'm a fussy guy when it ccomes to testing BMW steering and suspensions. But I did have one F10 5-series on test with 18" wheels, which had some vibration coming back to the steering wheel. I drove another example back to back, but on 19" wheels, was a completely different steering feel over the same roads, no vibration at all back to the steering wheel. This was way before the F30 was released and ahead of this issue of vibration being highlighted. To be honest I saw it as still having a run-flat trait, on the 18" wheel set, as wheel sizes were very critical on many of the earlier run-flat shod cars, even with hydraulic steering.
Hence why I ask if anyone has removed the wheel/tires and are running non run-flats and find it is different, or completely resolved. (Or even a different wheel and tire size). I still suspect the tires may be involved in generating the conditions which cannot be damped out within the EPS system.
HighlandPete