What is this part?
- Thread starter Bear Lake Cruiser
- Start date
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Harmonic damper.
Also known as "frame thingy" if you are doing IH8MUD searches.
Seriously.
-G
Also known as "frame thingy" if you are doing IH8MUD searches.
Seriously.
-G
- Thread starter
- #3
Frame Thingy...well. ok, I'll try to search that....just want to understand now what the hell it does and how.
It's only funny because it's been asked probably 100 times.... and everyone here laughs when a new thread about it pops up.
The original reason why it was installed was to deal with customer complaints about exhaust resonances. There was apparently some coupling of certain exhaust frequencies to the frame rail. The excitation of those frequencies caused the frame to vibrate (think: tuning fork) which amplified the exhaust problem and made it worse.
Adding mass to any mechanical object will help to move it's natural frequency. I'm sure that the substantial weight of this "thingy" helped to lower the resonant (Hz) of the framerail so that it was no longer reacting harmonically with the exhaust.
-G
- Thread starter
- #6
Greg, I just read the ton of other posts on this thing and your explanation of it sounds spot on. Take a tuning fork and place it on a guitar or a 5 gallon bucket and see how loud it becomes.
I love this thread topic (because I made one when I pulled my running boards off). The answers that I received were "creative" male bovine fecal matter... but enjoyable
1.21 Gigawatts worth of funnay!!! 
Now the real question is, why are they not on Aussie 100s?
Um, maybe the amplitude of resonate frequencies down under are upside down and don't cause the booming effect!
Um, maybe the amplitude of resonate frequencies down under are upside down and don't cause the booming effect!
Is the frame thingy complementary to, or redundant with, the running boards? i.e. does having them both installed have the same effect as removing them both, or do you need one without the other? Inquiring minds want to know...
When you see this thingy stuck on your frame you will want to remove it. Usually happens just after taking off the running boards. This is the point of no return.
From now on you will spend huge amounts of $$$ on what was a perfectly good family hauler with a thingy hidden on it's frame.
From now on you will spend huge amounts of $$$ on what was a perfectly good family hauler with a thingy hidden on it's frame.
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- Thread starter
- #19
Yes, I'm worried now. Putting it up for sale this afternoon!