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MTB Specific: What Tyre Pressures


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#65 Capricorn

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Posted 04 February 2012 - 05:04

wings: just remember that burping is only really for tubeless conversions. Proper UST setups, and even the UST ready ones, are not prone to burping. UST was designed to not have the tube lip unseat even at very low pressures.

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#66 Trek Fan

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Posted 04 February 2012 - 05:07

1.7 bar on my 29" Saguaro 2.2's - two different rims ZTR and WTB. Weigh 98 at the moment. Never have had a problem even on really rocky technical stuff

#67 Zoo Cookie 1

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Posted 04 February 2012 - 08:17

Conti mnt king front : 2
Conti race king back : 2,2
*no, i wont disclose my weight*

Working well for me, especially through thick sand

#68 kosmonooit

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Posted 04 February 2012 - 09:04

I was riding with a guy @ Barberton last weekend who claimed to be riding with 5 Bar in his tyres - that's a bit OTT!

I was running about 2.8 Bar, feels faster but quite bumpy. Normally 2.5 - 86 Kgs

Edited by kosmonooit, 05 February 2012 - 12:08 .

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#69 King_Crispy

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Posted 04 February 2012 - 10:29

View PostZoo Cookie 1, on 04 February 2012 - 08:17 , said:

Conti mnt king front : 2
Conti race king back : 2,2
*no, i wont disclose my weight*

Working well for me, especially through thick sand

Why not disclose your weight? Got a big bottom?
I always run at 2 bar on both 26" and 29er (I use 2.4 conti mountain king up front and race king 2.2 rear) and it works well.
Tried running lower on the 29er which resulted in a catostrophic accident and a hospital stay after a bad burp. Busted shoulder and back up to 2 bar...never to change

#70 Weight Weenie

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Posted 04 February 2012 - 11:19

Maxxis Aspens 2.1 folding bead on Stan's Podium MMX Rims. +- 63kg (racing weight) rider.

Front = 20 PSI (Dry) / 18 PSI (Wet)
Rear = 22 PSI (Dry) / 20 PSI (Wet)
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#71 Neg

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Posted 28 March 2012 - 09:46

i have the Giant P-XC2 rims, they came with the bike. currently running tubes and racing ralph's @ 3bar. Im 110k and anything lower i get snake bites. well, i have not yet had a snake bite on this bike but my previous bikes i had plenty.
before i bought my bike, i had a test bike, (29er with the same rims and tires) and was running @2.5bar. i had a snake bite at Groenkloof along the fence near fountains. now im wanting to go tubeless...

so the question is, are these P-XC2 rims tubeless read/tubeless and can i do the conversion with NON-tubeless tires and still run @3 bar? might try 2.8 too. Or will i have issues with side walls etc....?

#72 Capricorn

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Posted 28 March 2012 - 04:44

I had mine converted to tubeless. they are not tubeless ready. Mine held up just fine with no burping while using Kenda Nevegals. I run about 2.3/2.5 bar pressures, so not quite the same as yours.

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#73 Neg

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Posted 29 March 2012 - 08:07

So what you are saying is that i can convert and use normal non UST/tubeless tires and if i keep them at 2.5+ i should be fine? remember i was getting snake bites at 2.5bar.... so with tubless and non ust tires, wont burping be a possibility? ill be running the Rocket Rons until they are dead then probably go with Crossmarks or the ikons. 2.1's. will this influence the "stability" on the rim? currently have the 2.25 RR.

#74 Capricorn

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Posted 29 March 2012 - 08:13

View PostNeg, on 29 March 2012 - 08:04 , said:

So what you are saying is that i can convert and use normal non UST/tubeless tires and if i keep them at 2.5+ i should be fine? remember i was getting snake bites at 2.5bar.... so with tubless and non ust tires, wont burping be a possibility? ill be running the Rocket Rons until they are dead then probably go with Crossmarks or the ikons. 2.1's. will this influence the "stability" on the rim? currently have the 2.25 RR.

stability shouldn't be an issue. folding beads will take a bit longer to seat, whereas wire beads are harder to seat but do the best when used in tubeless configuration with non-ust rims. but that's just my personal experiences.
Burping can happen irrespective of what bead tyre one uses when going for a tubeless conversion and it is always a possibility with conversions. Always.
That said, I've done XC races with my tubeless conversions and the burping, if occured, was completely unnoticable, even over some really rough, rocky terrain,and i had forgotten that I had left my shock and fork on lockout. So I wouldn't be overly concerned with burping or 'stability' on the rim. It will work.

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#75 ramsew

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Posted 29 March 2012 - 08:15

View PostNeg, on 29 March 2012 - 08:04 , said:

So what you are saying is that i can convert and use normal non UST/tubeless tires and if i keep them at 2.5+ i should be fine? remember i was getting snake bites at 2.5bar.... so with tubless and non ust tires, wont burping be a possibility? ill be running the Rocket Rons until they are dead then probably go with Crossmarks or the ikons. 2.1's. will this influence the "stability" on the rim? currently have the 2.25 RR.
Its also about your rims, can they support a low PSI/BAR TL tire?

#76 Neg

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Posted 29 March 2012 - 08:16

Shot, will do the conversion and see how it goes....

#77 Neg

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Posted 29 March 2012 - 08:19

View Postramsew, on 29 March 2012 - 08:15 , said:

Its also about your rims, can they support a low PSI/BAR TL tire?

they are Giant P-XC2 rims. dont know much about these rims. maybe someone else can answer your question. when i bough them i was told that they are tubeless ready...??

#78 Capricorn

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Posted 29 March 2012 - 08:19

View PostNeg, on 29 March 2012 - 08:16 , said:

Shot, will do the conversion and see how it goes....
good man. let us know how it rolls ;)

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#79 Capricorn

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Posted 29 March 2012 - 08:20

View Postramsew, on 29 March 2012 - 08:15 , said:

Its also about your rims, can they support a low PSI/BAR TL tire?

based on my long term experiences with the rim and a tubeless conversion, it's just fine. The internet agrees.

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#80 wapad

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Posted 31 March 2012 - 12:24

View PostNeg, on 29 March 2012 - 08:07 , said:

So what you are saying is that i can convert and use normal non UST/tubeless tires and if i keep them at 2.5+ i should be fine? remember i was getting snake bites at 2.5bar.... so with tubless and non ust tires, wont burping be a possibility? ill be running the Rocket Rons until they are dead then probably go with Crossmarks or the ikons. 2.1's. will this influence the "stability" on the rim? currently have the 2.25 RR.

I had the same rims, just removed the tubes and put rim tape with a valve. I ran with geax saguaro's 2.2 and the fast trak lk at not more than 2 bar, I weigh 100kg +

I managed to run as low as 1.7-8bar rear and 1.6 bar upfront no problem no burps at all.

Down in the Cape I reckon the 2 worst tyres to use for burping are the rocket rons and crossmark non tubeless versions their sidewalls and beads are way to soft for guys over 70-75 kg and you could never run them at those low pressures, yet funnily enough the bike shops still go out and do the conversion and the guy thinks he's saving until a major wipeout