Completed with tecsound sy 70
For the arches use alubutyl:
Having ridden all types of surface for a week now, the results are quite disparate.
On paving stones, I think we're back to near normality, or at least it's quite acceptable.
The resonance frequency is between 40 and 80 Hz, so very low, and even with earplugs it's perceptible.
My impression (but I'm not an engineer) is that at low speed, even a small shock absorber travel causes a wave that reverberates throughout the chassis.
The mg4 has a lot of hollow bodies, so I think it amplifies as it should...
We must be in the 30-40dB range.
On the motorway, no worries except for a very slight noise which I can't tell if it's linked to the aerodynamics. But I think it's resonance noise, which is always faintly audible.
On some abraded surfaces, where it used to be an ordeal, it's clearly much better.
Where the resonance noise persists is when the pavement makes ripples as a result of progressive subsidence or sometimes even on some new pavements.
I spoke to a surveyor friend of mine who builds motorways and he said that this phenomenon, which is linked to certain wavelengths, should be controlled on new pavements. The problem is that often, in the case of renovations involving only surfacing, this work of levelling out with a very long beam is not done, which costs time, money and ..... Know how...
This explains why I sometimes have the impression that I'm hearing more of this resonance when the pavement has just been redone.
To sum up, there's clearly been some improvement, even if the mg4 is still noisy on some roads.
As for resonance noise on 'good roads', I have the impression that it passes under the radar of the butyl, unlike higher intensity noise which is well absorbed.
I'd have to throw some expanding foam where the shock absorber are fixed, but I'm not sure I'd dare...
Enjoy!
