Thanks for all the helpful comments, probably a lot to check and more than one possible reason to consider.
Good to know that the issue is not depending on the wideness of wheel/ tyre. (my wrong thought was that when considering a center locked but narrow wheel, a stronger leverage effect from the surface to the center of the wheel could effect a stronger lateral movement resp. force...also to the brakes).
Yes, brake reaction bars were mounted soon after I got her in autumn 2014.
Brake discs were every time changed in pairs. And the first 2000 or 3000 km after such a change she feels fantastically smooth when braking. She is not in use on trackdays etc. I drive her in a sporty manner from time to time. But she feels so light weight and I never had a car where the brakes had to "work" less than with her.
The front cross frame and the tie bars were checked the last time but in two weeks from now I again have a garage date and it should be checked again. I myself will have a look also.... if I can discover something wrong at all...now being TM expert
At least the helpful acoustic test I can do.
The left side hub only (seen in driving direction) was changed when they again changed the discs in autumn 2016 for the last time.
This hub resp. the brake disc mounting threads on the hub were out of tolerance / center which caused really nasty, small but strong and sharp hits in the steering wheel when driving ca. 130 km/h and faster...if my words describe it somehow correctly. With the change of this hub the sharp hits are happily gone but the disc wobble and the bad quick pulsing pedal feel is back again.
When the wooble occurs it rises in a not linear way. First you feel that something is wrong and then it becomes stronger and stronger after 1000 km more.
My driving style even changed a bit when driving her. I don't brake so hard in front of curves but I drive smoother anf use the brake less and less if the situation allows. Which is a positive side effect in general.
