Tyre valve attachment?

[Hoggs]

tis the season of goodwill. You can all have a chocolate coin and internet points.

Remember on the internet no one remembers the post above the one they're typing let alone from 3 days ago

tra la la la laaaaaa

[Mr Fro]

So you agree with what I said 3 days ago?

 

Well... yes - having just refreshed my memory of what you said.

Don't think I disagreed with you in the first place though!

[megawatt]

Thanks.

[Joeman]

But (pedantic head on), is it not Centripetal Force?

 

It's actually the absence of sufficient centripetal force that's the problem..

[Joeman]

So what force causes the tyre valve to get ripped out and why?

 

Centrifugal.

As the wheel spins, the force acting on the valve is in an outwards direction. As the wheel speed increases, so does the centrifugal force (g) to a point where it overcomes the rubbery bit and the metal bit moves towards the rim. High enough wheel speed will give enough centrifugal force to exceed the shear limit of the rubber and off it goes.

The force is quite large - if you consider those spinny things used in astronaut training - the person gets quite badly squashed down and pass out under single digit g. Assuming a 17" rim and a 10 gram valve, your valve will undergo somewhere in the order or 350-400g at 70mph.

Just because I like stiring things up.

It's not centrifugal force that makes your angled valves rip out, it's the fact the valve isn't strong enough to provide sufficient centripetal force to prevent it ripping out.

Like a heavy weight spinning round your head on a bit of string, it's not the centrifugal force that breaks the string when you get too fast, it's that the string can't provide sufficient centripetal force to keep the weight spinning - the required force exceeds the tensile strength of the string so it snaps and the weight flies off in a straight line as there is now no centripetal force causing it to move in an ark..

Centrifugal force doesn't exist.

[Hoggs]

Just because I like stiring things up.

 

*hits Joe on the nose with a rolled up newspaper* No, bad Joe, no.

[Chrissb6]

Folks, l just screw mine on check the tyre pressure if necessary blow it up unscrew take off and put back into the box simple's

[Joeman]

Just because I like stiring things up.

 

*hits Joe on the nose with a rolled up newspaper* No, bad Joe, no.

 

I think the forums broken. Nobody took the bait!!