2017 GS - vibration on back brake

[AndreSwartKat]

I'm new to the world of BMW and was hoping to get some advice, please

I'm buying a 2017 GS with very low mileage and the bike seems to be in perfect nick at a first glance, but during a test-ride there were a few things which caught my attention, but I've been told these are all normal characteristics of this bike - I'm hoping someone can advise:

1.  When applying the back brake (at lower speeds particularly) there's a definitive vibration on the brake pedal - almost similar to the high frequency vibration that one would feel on a car brake pedal when ABS kicks in -  I've been told this is normal and only a result of the KAROO 3 tyres..? I've asked for the pads to be replaced, but it made no difference and I can't see any obvious irregularity on the discs.

2.  At low speeds (40 - 80 km/h) there's a humming sound coming from the front of the bike - I've been told this is normal and only a result of the KAROO 3 tyres in conjunction with some sort of 'dyno-genreated' sound which is common to the GS..? Sounded like a made-up story to me.  The sound seems to dissipate as you increase speed (and wind-noise increases).

3.  At low speed (2nd gear, 40km/h) when closing the throttle there's a definitive vibration (almost like a grinding vibration generated by the engine) which one can feel in the footpegs - I've been told this is perfectly normal.

I don't know if I'm imagining things or just not used to normal characteristics of a different kind of engine/bike.

Any advice or comments would be much appreciated.

 

[Sommer Ek]

 

[Jughead]

 

[detour]

 

[AndreSwartKat]

 

[Duke916]

 

[Antois]

 

[AndreSwartKat]

 

[ruanb]