Primary case soud dampener?

[-deuced-]

I have noticed the sound dampener in previous threads but I'm puzzled how it actually functions. Noise is just vibrating air. Does the primary cover act like the diaphram in a loudspeaker? If I attach a big lump of weight to the primary cover does that inhibit oscillation and the transmission of sound?

Also it seems that the rocker covers closely follow the contours of the rocker boxes internal components. Is that another way to quieten sound? Less air to vibrate equals less noise?

[FSG]

Does the primary cover act like the diaphram in a loudspeaker?

it does if it's allowed to vibrate

If I attach a big lump of weight to the primary cover does that inhibit oscillation and the transmission of sound?

yes


This isn't anything new, HD also did it to some extent when they removed the primary chain inspection hole/cover

[-deuced-]

This isn't anything new, HD also did it to some extent when they removed the primary chain inspection hole/cover

I am so far behind the times.

[rbabos]

Basically it takes the high frequency vibration out that would occur on the wall of the cover. It would be very minimal however. Most would not really hear a difference.
Ron

[ultraswede]

The same thing was used on touring models for japan, I know for sure 09 Touring and 2016 CVO ltd.

There #60818-07 is bolted in the trans cover.
Looks like the same part on the M8.

[glens]

Well it might dampen some sound, but it would be sound not that the rider hears, but those who you're riding past.  Probably the real reason for it is so you can't install a compensaver.

[choseneasy]

The sound trap they run the bike thru would pick up the noise, which I believe brought out this new sound damper.
  If the counter balancer whines a bit- they need to remove noise from somewhere to meet noise requirements.

[rbabos]

Well it might dampen some sound, but it would be sound not that the rider hears, but those who you're riding past.  Probably the real reason for it is so you can't install a compensaver.

Agree, only the machine will pic up the sound differences. EPA total noise limit kind of deal where it would be noticed. As for the Compensaver, unknown at this point due to primary depth. Otherwise that damper is only bolted in, much like the softail outer primary support was. I doubt very much it was a deliberate attempt to block that area for the Compensaver tray.
Ron

[Ohio HD]

Remember the felts in the Pan Head covers? That's what they were for, absorb some noise. 


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