Big-wheeled burping
 

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[Closed] Big-wheeled burping

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I've had several front wheel burps in my still quite limited experience of riding 29" wheels. Never had any riding 26". Have I just been unlucky or are big wheels more prone to burping?

Astound me with anecdotes and stun me with science...


 
Posted : 10/04/2013 7:47 am
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It depends on the rims and tyres.

I have a set of 29" DT Swiss rims that I have converted to tubeless with some Stan's tape and they go up fine, but can burp if I ride them too hard, even with lots of pressure. I also have a set of 29" Chinese carbon rims I can't get those to burp whatever I do, even with little pressure it is hard to get the tyre to leave the rim.

My experience with 29" tubeless is a bit limited, but from my 26" days narrow rims with a wide tyre also tend to be more prone to burping.


 
Posted : 10/04/2013 8:01 am
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I've said it before, and I'll say it again - the answer to [i]any[/i] tubeless problem is... UST!

Can't understand why, in this day and age, people would muck about with rim strips, compressors, burping, sealing tyre walls with sticky liquid, when there's a simple and reliable system designed from the bottom up specifically to avoid all those hassles 🙄

Luddites the lot of ya 😉


 
Posted : 10/04/2013 8:16 am
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more pressure needed

any tyre will burp if the pressure is low enough, even UST tyres


 
Posted : 10/04/2013 10:15 am
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It's nothing to do with wheel size just rim/tyre combos, pressure and the way you've tubeless'd them.


 
Posted : 10/04/2013 10:16 am
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Spesh used to make a "DH" tyre called the evil twin that had a sort of rubber lip that went over the outside of the rim to hold it in place.

Most bikes had rim brakes then and they were impossible to use if yours did (I cut the lips off mine) but they might be great for stopping burps these days


 
Posted : 10/04/2013 10:32 am
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Just put one of those "inner tube" thingies in. Sorted. 🙂


 
Posted : 10/04/2013 10:32 am
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It's lack of pressure as said further up.

Other contributing factors haven't been mentioned, such as are they proper tubeless ready tyres, are they fitted properly on tubeless ready rims or with the correct conversion kit, are you a riding God with awsum cornering speedz?


 
Posted : 10/04/2013 11:24 am
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So the consensus is that a burp's no more likely on a 29er, all else being equal?

My experiences have been with proper tubeless ready rims (Crests and whatever comes on a Whyte T129) running 2.3ish tyres (Bonty TLR on the Crest and Ardent or Advantage on the other). I run about 22-24 psi. The T129 burp was on a borrowed bike, hence the vagueness about tyres and rims, and I suspect it was at lower psi.


 
Posted : 10/04/2013 11:45 am
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perthmtb - Member

I've said it before, and I'll say it again - the answer to any tubeless problem is... UST!

Full on UST tyres are heavy, and they can still burp.


 
Posted : 10/04/2013 11:57 am
 Sam
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perthmtb - Member
I've said it before, and I'll say it again - the answer to any tubeless problem is... UST!

Can't understand why, in this day and age, people would muck about with rim strips, compressors, burping, sealing tyre walls with sticky liquid, when there's a simple and reliable system designed from the bottom up specifically to avoid all those hassles

Because there are literally a handful of genuine UST 29er tyres out there, and those are outrageously heavy (like 35% more than the non-UST version), and a bastard to fit. The only UST 29er rim I know of is the Mavic Cro29max and they are a bit rubbish.


 
Posted : 10/04/2013 1:17 pm
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perthmtb - Member

I've said it before, and I'll say it again - the answer to any tubeless problem is... UST!

Can't understand why, in this day and age, people would muck about with rim strips, compressors, burping, sealing tyre walls with sticky liquid, when there's a simple and reliable system designed from the bottom up specifically to avoid all those hassles

Luddites the lot of ya

luddite? maybe

tightar53? definitely

ghetto tubeless here, no problems at all now i have a 9p-inflator* (*Tm singletrackworld forum corp)


 
Posted : 10/04/2013 1:31 pm
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its a simple fact that a wheel with a larger radius is much more likely to burp air.
the tyre makers know this, but the only way to fix the issue is to make the tyres so thick that fitting them to the rims would require thumbs of steel.


 
Posted : 10/04/2013 1:37 pm
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science in action. be astounded.


 
Posted : 10/04/2013 1:40 pm
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Ah, so that's why I need to go 650b. I knew there was a reason. Actually, I think I'll try adding a psi or two


 
Posted : 10/04/2013 4:27 pm
 JoeG
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Richard Cunningham wrote a pretty good article on Pinkbike called [url= http://www.pinkbike.com/news/Tech-Tuesday--Wider-Rims-Are-Better-and-Why-Tubeless-Tires-Burp-.html ]Wider Rims Are Better and Why Tubeless Tires Burp Air [/url]


 
Posted : 11/04/2013 2:43 am
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The T129 burp was on a borrowed bike, hence the vagueness about tyres and rims
,

Maxxis Ardent 29x2.25 on a WTB sti 19, stock on the bike.

and I suspect it was at lower psi.

It was probably < 20, more like 17 or 18.

I'm happy the setup was done OK, I've done loads, I don't think setup was the cause. (I'm not counting psi as setup).


 
Posted : 12/04/2013 7:53 pm
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good link Joe

basically he's saying Flows not Crests


 
Posted : 12/04/2013 8:50 pm