Why do bike bells stop working when they get wet?

[biggs682]

I'm surprised manufacturers dont combine a bell into a helmet.

And how would it work ???

 

[mudsticks]

And how would it work ???

Reckon some kind of complex sound generating device could be inserted into the helmet.

It could be made to say.

"Oi you plonker - geddoff the cycle path"

Or some such.


This is all just BIG talk you understand??

I usually resort to a slightly terse

"excuse me, please"

Or else a more sarcastic "Hello-ooo!"

 

[mjr]

Knog Oi! bells rock but beware of the springer dinger thing; I have ruined two by getting gloves, mitts, other clothes caught in it and stretching or bending it

Maybe this is a good rule? If a bell has a pinger that can bend (plastic or on a cheap spring), it's probably not worth an actual cyclist buying because it won't last - leave them to the "bought a bike, rode it twice, left it in the shed" market.

 

[EltonFrog]

I'm surprised manufacturers dont combine a bell into a helmet.

That's what they call a Bell End innit?

 

[Andy in Germany]

Never heard of Bell helmets?

Yeah, but they don't work. I tried pinging mine: Nothing.

 

[classic33]

Yeah, but they don't work. I tried pinging mine: Nothing.

Might be wet.

 

[mjr]

Might be wet.

Try rubbing your wet helmet with a towel until it's dry.

 

[rogerzilla]

It's a reason to buy an Air Zound.

 

[classic33]

It's a reason to buy an Air Zound.

They get folk confused in use though.

 

[Racing roadkill]

Sound waves are longitudinal. They rely on compression of air. Liquids don’t compress, so because rain is a liquid, you don’t get the requisite compression, to set up the longitudinal wave.

 

[rogerzilla]

Sound does travel underwater, so I'm afraid that's incorrect.

 

[andrew_s]

Well, why do they?

The striker imparts energy into the bell, in the form of vibrations, which, because of the shape of the bell and where the striker hits it, are mostly round the edge.
The energy from the vibrations then dissipates into whatever's touching the bell.
It doesn't take much energy to move the surface layer of air, so the imparted energy dissipates slowly, and you get a sustained ring.
If there's water on the bell, moving it takes a lot more energy, so the vibrational energy is lost quickly, and there's no ring, just a brief "plink" sound.

The bells that work best in the rain are those that don't get much water on the ringing part. In the case of the basic Widek "bring-bring" bell, the top part gets water on, but the underside also rings, and is kept mostly dry by the top part.

 

[Ming the Merciless]

Because the rain makes them sad, they do not want to ring.

 

[MontyVeda]

I'm surprised manufacturers dont combine a bell into a helmet.

brilliant idea! The ding in the event of an off will alert the emergency services

 

[Pat "5mph"]

@andrew_s what a detailed explanation, thank you.
I must add to it that, after a bell gets dry again after getting wet, it will still not work as cling clongly as before.
Why?
Because it gets rusty!
The CatEye bell was no exception, dousing it in WD40 was useless, the spring can only produce a meek click now - for £10 I'm not amused!

But I've always had a yearning for one of those squeezy rubber ball, and horn arrangements..

Pound shop sells them sometimes: on mine the rubber ball soon detached itself from the horn, on reattachment it would only produce a faint globby kind of sound.
I got gifted another horn recently, seems a better quality than the pound shop one not fitted it yet.
Horns are great if used occasionally on a wired up, oblivious pedestrian, or during critical mass .... I fear they are not polite though

Got myself a new bell, a Victoria Pendleton endorsed one
It does not fit the handlebar of my Genesis