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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: steveg on January 20, 2017, 06:18:25 AM

Title: 2016 Zero SR - 'Squonk' louder when bike is wet?
Post by: steveg on January 20, 2017, 06:18:25 AM
I've noticed the low frequency 'squonk' sound the bike makes as I accelerate off the line is much (much) louder when the bike is wet than it is when dry. Anyone else experience this, or know what that's all about?

Thanks!
Steve
Title: Re: 2016 Zero SR - 'Squonk' louder when bike is wet?
Post by: MichaelJohn on January 20, 2017, 07:31:54 AM
I think what you're referring to is the "wounded Wookie" sound. I don't ride mine very often the wet so I don't know if it's louder then but eventually the sound goes away. It was a common topic a while back.

Edit: I'm pretty sure it's the belt.
Title: Re: 2016 Zero SR - 'Squonk' louder when bike is wet?
Post by: Low On Cash on January 20, 2017, 07:33:43 AM
Steve - Does it sound like its coming from the drive belt, as you know the belt is always groaning to a point and like a belt on a car they can sound different when they get wet- I'm sure most of us have heard fan belts in the morning squeaking.
Title: Re: 2016 Zero SR - 'Squonk' louder when bike is wet?
Post by: mrwilsn on January 20, 2017, 10:22:51 AM
The noise is from the belt.  Think of it like a guitar string.  Small vibrations from the motor get played by the belt like music.  Some of the noise is also from the vibration of the motor itself but it is basically getting amplified by the belt.  Change the tension and you change the pitch.  That's also the reason you can notice differences in the sound based on how hard you twist the throttle...under higher torque the motor vibrates a little more and the belt will be tightened giving a higher pitch.

I have actually ridden enough that I can tell a belt that is over tightened just by the sound.  There are apps that check belt tension based on this principle.  I can also tell the difference between the older 14mm wide belt and the newer 17mm wide belts that come on most of the 2017 lineup.  As you might expect the wider belt has a little bit of a deeper pitch.

The question mark is why do you notice a difference just from it being a rainy day.  I have definitely noticed this same phenomenon many times....as recently as just 30 minutes ago on my rainy ride home in fact.  I have two theories but haven't been able to confirm if either are correct of even possibly a combination of the two.

1. The changes in temperature and humidity cause the belt to swell which results in a tighter belt and the change in noise.

2. The addition of the water on the belt changes the pitch by itself....playing a wet string vs. a dry string.

I have thought of ways to test but haven't done so yet.

It gives a new meaning to tuning your bike  :D
Title: Re: 2016 Zero SR - 'Squonk' louder when bike is wet?
Post by: Justin Andrews on January 20, 2017, 02:01:08 PM
Yep, my 12, 13 and my current 15 all played the Wounded Wookie when accelerating in the wet.
Title: Re: 2016 Zero SR - 'Squonk' louder when bike is wet?
Post by: BrianTRice@gmail.com on January 23, 2017, 10:36:36 AM
This is already well known: http://zeromanual.com/index.php/Common_Problems#Groan_Sound (http://zeromanual.com/index.php/Common_Problems#Groan_Sound)
Title: Re: 2016 Zero SR - 'Squonk' louder when bike is wet?
Post by: MajorMajor on January 23, 2017, 03:11:49 PM
There's actually a solution for this?
That would be incredible if it worked.

Is this the right kind of spray?
https://www.youtube.com/watch?list=PL0F79444CB482921F&v=JDA9aPXx_qc (https://www.youtube.com/watch?list=PL0F79444CB482921F&v=JDA9aPXx_qc)

Title: Re: 2016 Zero SR - 'Squonk' louder when bike is wet?
Post by: Erasmo on January 23, 2017, 03:30:59 PM
I think what you're referring to is the "wounded Wookie" sound. I don't ride mine very often the wet so I don't know if it's louder then but eventually the sound goes away. It was a common topic a while back.

Edit: I'm pretty sure it's the belt.
That's a brilliant description.
Title: Re: 2016 Zero SR - 'Squonk' louder when bike is wet?
Post by: Curt on January 24, 2017, 12:45:10 PM
Haha, I was wondering about the wretched wounded Wookie wailing on my waterlogged way homeward this week, then found this winning web thread.