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Tubeless spoke tension drop

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Tubeless spoke tension drop

Old 06-19-21, 01:41 AM
  #26  
Racing Dan
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Originally Posted by Psimet2001
I recently warrantied one that did the same. The issue is more their valves or rather their retaining nut for the valve. They drill it to allow any air that leaks into the lower chamber of the rim to escape. I have never had or seen this issue with any other rim when using it tubeless. Including the ones we use.

In other words if the lower rim chamber gets pressurized it will blow completely off the rim in the most catastrophic and exciting way.
The issue appear to be the rims not having drain holes like any other normal rim. Thus the need for an air bleed channel in the valve lock nut to prevent the rim from blowing up in case the TL tape fails. Should be fun having the rims filled with rain water that cant drain
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Old 06-19-21, 04:00 AM
  #27  
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Originally Posted by terrymorse
Yes a tubeless tire will exert more rim force than a tire+tube at the same pressure, but for a much simpler reason than the engineer-splaining in that article, above.

Quite simply:

Air pressure always exerts a force perpendicular to its container walls. Remove the inner tube, and:
  • you slightly increase the size of the container
  • the total force from air pressure on the container rises
  • the air pressure produces more radial inwards force on the rim
  • the rim diameter shrinks
  • the spoke tension drops
That is all. NBD.

Q: Why are (some) engineers so bad at explaining things simply?
A: Because they don't adequately understand the problem.
Thanks for the explanation.

But, of course, there are multiple factors at play.
Tire size? 23mm, 25mm, 28mm?
Pressure?
Tube Type?
Is a tube in a tubeless tire the same as a tube in a tube tire?
Brand to brand variability in tire sizes and designs?

What about those riders that pump once to say 110PSI, then ride for a month or so until the pressure has dropped to 80psi?

There are also several recommendations to run tubeless tires at slightly lower pressure than tube type tires.
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Old 06-19-21, 04:45 AM
  #28  
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Originally Posted by CliffordK
There are also several recommendations to run tubeless tires at slightly lower pressure than tube type tires.
It’s a standard recommendation and one of the benefits in running tubeless.
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Old 06-19-21, 05:22 AM
  #29  
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Originally Posted by PeteHski
It’s a standard recommendation and one of the benefits in running tubeless.
In truth a requirement. After all it is true many tyres are rated differently depending if they are installed tubed or not. Rims too.

Seems to me the no pinch flat argument is just very convenient and to a large extent FUD to make you believe you cant run normal road tyres at reasonable pressures with out pinch flatting every other ride. I beg to differ. Ive been running 28mm on mixed tarmac/gravel for moths at 50-60 psi, with very little issues.
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Old 06-19-21, 08:36 AM
  #30  
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Originally Posted by Seattle Forrest
There are a lot of things that aren't wrong with tubeless, bit of you like having your panties in a bunch I'm sure you can imagine this is really scary. I'm sure the idea of actually riding a bike must be terrifying!
Originally Posted by WhyFi
I've been trying to come up with something that I'm neither personally nor practically interested in, but about which I can study just enough to shake my fist at it whenever the opportunity presents itself. No luck, so far, though - I just can't get my undies bunched over something that I'm not interested in; I don't know how these guys do it.
He's had years of practice.
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Old 06-19-21, 09:08 AM
  #31  
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Originally Posted by PeteHski
It’s (running tubeless at a lower pressure) a standard recommendation and one of the benefits in running tubeless.
As I explained above, since the interior volume of a tubeless tire is greater than an equivalent tire+tube, the tubeless tire needs to be at a lower pressure to have the same ride character.

I don't think that's a benefit, just a peculiarity of tubeless.

A low-pressure tubeless benefit is the ability to use a very low pressure without the fear of pinch flats.
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Old 06-19-21, 09:20 AM
  #32  
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Originally Posted by CliffordK
But, of course, there are multiple factors at play.
Tire size? 23mm, 25mm, 28mm?
Pressure?
Tube Type?
Is a tube in a tubeless tire the same as a tube in a tube tire?
Brand to brand variability in tire sizes and designs?
Lots of variables to look at if you want, but the only things that affect the compression of the rim (the subject of this thread) is air pressure and interior volume of the tire and tube (if there is one) when inflated on the rim.
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Old 06-19-21, 03:52 PM
  #33  
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Originally Posted by terrymorse
As I explained above, since the interior volume of a tubeless tire is greater than an equivalent tire+tube, the tubeless tire needs to be at a lower pressure to have the same ride character.

I don't think that's a benefit, just a peculiarity of tubeless.

A low-pressure tubeless benefit is the ability to use a very low pressure without the fear of pinch flats.
I get that, but still tubeless tyres feel more compliant at those lower pressures. I'm certainly not the first to note that effect! Pinch flats were more of an issue for me on mtbs, which tubeless has obviously eliminated.
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