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Lowest pressure for tubeless?

Zark

Hey little girl, do you want some candy?
Oct 18, 2001
6,254
7
Reno 911
Thats a tricky question without an easy answer. It depends on the rim, tire, terrain and ride style.

You'll know when its too low and you burp the tire.
My experience is 30 psi is pretty typical.
 

demo8razor

Monkey
Mar 31, 2008
250
0
i've run 20-25 psi in michelin 32s with ghetto setup, im 220ish and ride mainly rocky stuff i have also ridden intense tires with 15-20 psi with tubes
 

DirtyMike

Turbo Fluffer
Aug 8, 2005
14,437
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I have run 18 lbs on a stans system, with Maxxis 2.5 minions. Rough terrain, rocky loose and wet and rooted. And I weigh in at 252. The biggest trick to remember, and this is the kicker, the more air volume you have in a tire, the less pressure it will take to support the same weight. So in all reality, it all has to do with tire total volume vs rider weight.
 

Bicyclist

Turbo Monkey
Apr 4, 2004
10,152
2
SB
I tend to run 20-25 depending on terrain, both with and without tubes. But I'm also a featherweight.
 

Tootrikky

Monkey
Jul 31, 2003
772
0
Mount Vernon
195# rider, 823's with Non UST 2.5 Minion's.
I find that rolling the sidewalls over in berms and rolling resistance with tubeless is more of a factor then preventing pinch flats. I have ran 25#'s in the front in wet sloppy conditions where traction is hard to find and railing berms/turns is impossible. Anytime there is traction to be found however 27# up front and 28.5# in da rear is the lowest I can get away with.
 
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dhkid

Turbo Monkey
Mar 10, 2005
3,358
0
Malaysia
i am 140lbs, and the lowest i would go with 2.5 maxxis tires is around 20 psi.

any lower and the tires fold over like mad. takes the fun out of berm bashing.
 

brian field

Monkey
Feb 5, 2007
100
0
thing is that i run 20-25psi rear and front. so i don't know should i go for tubeless, and will my tire burp air at those pressures? i am 150 lbs
 

DirtyMike

Turbo Fluffer
Aug 8, 2005
14,437
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My own world inside my head
If your using a stans kit, It will hold, I cannot say for the other systems, I dont have eany experience with the others. Like others said you will roll the tire if your too low which is more of a concern with the lower pressure than burping air. That part I didnt mention in my first post.

The real question for yourself is, is it worth the hassle for you? I used to run stans, I have since gone back to tubes in my tires. With Minions I can still run 25 lbs without any problems.
 

Tootrikky

Monkey
Jul 31, 2003
772
0
Mount Vernon
If your using a stans kit, It will hold, I cannot say for the other systems, I dont have eany experience with the others. Like others said you will roll the tire if your too low which is more of a concern with the lower pressure than burping air. That part I didnt mention in my first post.

The real question for yourself is, is it worth the hassle for you? I used to run stans, I have since gone back to tubes in my tires. With Minions I can still run 25 lbs without any problems.

IMO Lower rolling resistance is the biggest advantage tubeless tires offer over tubes. Supposedly they roll faster than tubed because there is no friction between the tube and tire in theory which I don't understand. It's quite apparent however, when riding the same tires back to back tubed/tubeless, that tubeless just rolls faster.

Pinch flats are pretty uncommon today if you run the right setup. How many WC pros are running tubes and how often do they flat?
 

DirtyMike

Turbo Fluffer
Aug 8, 2005
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Ok, I cant tell a difference in rolling resistance at all between tubed and tubeless. But what I can tell, is the bigger range of pressure you can run without worring about your tube. I hear what your saying about pinch flats not being as common with the proper setup, but I see it where people are running a good tire, tubed, with less pressure than it is supposed to have, and those are the ones getting pinch flats. Even myself, I run less than the min pressure reccomended, specifically, My rear tire is a Maxxis Minion, and I run about 28 lbs, Min is 35 lbs.

But hey proper setup, good tires and its all good. Ok I am rambling on a bit, its all good.




FWIW last time I pinched, I tore off a chunk of my wheel.
 

Tootrikky

Monkey
Jul 31, 2003
772
0
Mount Vernon
Ok, I cant tell a difference in rolling resistance at all between tubed and tubeless. But what I can tell, is the bigger range of pressure you can run without worring about your tube. I hear what your saying about pinch flats not being as common with the proper setup, but I see it where people are running a good tire, tubed, with less pressure than it is supposed to have, and those are the ones getting pinch flats. Even myself, I run less than the min pressure reccomended, specifically, My rear tire is a Maxxis Minion, and I run about 28 lbs, Min is 35 lbs.

But hey proper setup, good tires and its all good. Ok I am rambling on a bit, its all good.




FWIW last time I pinched, I tore off a chunk of my wheel.

Sorry but a 252 lb rider with 18#'s of tire pressure is ridiculous, especially on 2.5 Maxxis!
 

DirtyMike

Turbo Fluffer
Aug 8, 2005
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Sorry but a 252 lb rider with 18#'s of tire pressure is ridiculous, especially on 2.5 Maxxis!
Yeah, it was, but it was an answer to the question, It was sloppy muddy, and it was about the only way to get any kind of traction at all. It worked for the ride in question, and I couldnt imagine running it that low for any dry condition out there. Like I said , normally I am running about 28 front and rear.
 
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Tootrikky

Monkey
Jul 31, 2003
772
0
Mount Vernon
Ok so a freak occurrence happened to work for you one time and now you are advising others it's the low pressure threshold for tubeless? Come on 18#'s is retarded. Do your fellow riding buddies run 18# in sloppy conditions, and or have you ran 18#'s more than once? May be if you and several other riders that you know had consistently run 18#'s,,, may be then it would be worthwhile advice? I am not saying you're full of it either......... just that you might word your experience differently, because it's way out of the normal range for tubeless pressures.
 
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DirtyMike

Turbo Fluffer
Aug 8, 2005
14,437
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Ok so a freak occurrence happened to work for you one time and now you are advising others it's the low pressure threshold for tubeless? Come on 18#'s is retarded. Do your fellow riding buddies run 18# in sloppy conditions, and or have you ran 18#'s more than once? May be if you and several other riders that you know had consistently run 18#'s,,, may be then it would be worthwhile advice? I am not saying you're full of it either......... just that you might word your experience differently, because it's way out of the normal range for tubeless pressures.
Well, ok lets get overly technical then, I do not advise running less than 25 lbs on any given tubless system, When I an 18, it was on a stans kit system on Sun Singletracks. Now lets also go back to my original post, were I talked about the lowest pressure you can run will be dependant on total tire volume, VS total rider weight, I will add now that it will also depend on the construction of the tire as well.

Now, lets talk experience, Stans strips, when set up properly, will stick to the tire itself, so when you start rolling your tire, you can roll it alot further than other tubeless systems before burping air, it does NOT work the same when your running Ghetto tubeless. Little video to help visualize that, given these are all standard tire, but its a good presentation.
http://www.notubes.com/moviecompar.php


Also going back to my second post, were I said myself about the amount of air pressure someone wanted to run<20-25> and I stated with the stans system would be fine at that pressure, but I wasnt sure about other systems.


And in a final responce, the original post was asking what you Can run in tubeless, not what you should run in tubeless. I listed what I have run, and what I know works with a given system. I dont remember saying "Hey you should all run 18 lbs" I just remember answering a question with what I ahve gotten away with, without having a problem. I dont remember in any of my posts "Advising" that people should run there tires this way, I also remember the OP asking if he could get away with running 20-25 and IMO he will be just fine.


I do not belive for one second that the advantage of tubeless is lower rolling resistance. Been demoing a set of DA tubeless wheels on the road bike, and guess what, top speed down My favorite decent is the same, but its one hell of a supple ride, better quality of a ride, feel better connected in teh corners. Roll faster, no, feel better, yes.


If you want lower rolling resistance, raise your air pressure.




EDIT, I also pointed out the Minimum reccomended pressure on a standard 2ply Minion as being 35 psi
 
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no skid marks

Monkey
Jan 15, 2006
2,511
29
ACT Australia
I do not belive for one second that the advantage of tubeless is lower rolling resistance. Been demoing a set of DA tubeless wheels on the road bike, and guess what, top speed down My favorite decent is the same, but its one hell of a supple ride, better quality of a ride, feel better connected in teh corners. Roll faster, no, feel better, yes.
If you want lower rolling resistance, raise your air pressure.
the friction created by a thin road tyre in tube in relation to your weight is a lot less and therefore a lot less relevent and noticeable.
The friction is created by your tyres profile changing as it contacts the ground, the tyre then makes the tubes profile change by friction. As the tyre deformes, the tubes shape resisits it and energy is transferred from the tyre to the tube.
When you pull your pants off, and your underwear comes down also, you are wasting energy pulling down the underwear, compared to pulling pants down without underwear.You are adding another surface area contact patch,Same with a tube.
UST tyres are genrally better I've found for not burping because they're genrally a smaller inside diameter(harder to get on rim).
Put the effort in, make proper rim strips from 20" tubes(Ghetto Pro)and use UST tyres and sealant(hardest tyre you'll ever install with the rim strip)for the most bulletproof cheap set up. Run UST tyres on 823s for the best strength/weight/reliability.
I'm 68kg and run 25f and 28r with 823/UST 2.5 Maxxis on DH bike,
and Ghetto pro with Stans and 2.1 Z-Max on my do it all hardtail, that I DHed on(rather slowly) on 30PSI r and 38F last weekend with no issues and feeling the rim bottom out a few times.
 
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- seb

Turbo Monkey
Apr 10, 2002
2,924
1
UK
With Michelins I could run as low as 20psi NO worries. With Maxxis I tend to burp even at 30psi sometimes.
 

DirtyMike

Turbo Fluffer
Aug 8, 2005
14,437
1,017
My own world inside my head
the friction created by a thin road tyre in tube in relation to your weight is a lot less and therefore a lot less relevent and noticeable.
The friction is created by your tyres profile changing as it contacts the ground, the tyre then makes the tubes profile change by friction. As the tyre deformes, the tubes shape resisits it and energy is transferred from the tyre to the tube.
When you pull your pants off, and your underwear comes down also, you are wasting energy pulling down the underwear, compared to pulling pants down without underwear.You are adding another surface area contact patch,Same with a tube.
UST tyres are genrally better I've found for not burping because they're genrally a smaller inside diameter(harder to get on rim).
Put the effort in, make proper rim strips from 20" tubes(Ghetto Pro)and use UST tyres and sealant(hardest tyre you'll ever install with the rim strip)for the most bulletproof cheap set up. Run UST tyres on 823s for the best strength/weight/reliability.
I'm 68kg and run 25f and 28r with 823/UST 2.5 Maxxis on DH bike,
and Ghetto pro with Stans and 2.1 Z-Max on my do it all hardtail, that I DHed on(rather slowly) on 30PSI r and 38F last weekend with no issues and feeling the rim bottom out a few times.


Love that analogy, that made me laugh this mornig, I needed that. I still dont belive it to be enough to make a enough of a difference to list it as an added benefit.

I agree that a Proper UST system would be the way to go it you wanted to rub tubeless, 823 is probably my favotire wheel, The new UST tires mare much, much better than when the technology first came out, I wasnt trying to slam Proper UST with my video I linked, just show about burping.
 

dh415

Chimp
Dec 6, 2006
56
0
novato
I have tubes and run 20psi in both front and rear with minions 2.5 and havent had a pinch yet. but im also 155.
 

Uncle Cliffy

Turbo Monkey
Jan 28, 2008
4,490
42
Southern Oregon
I'm a fan of the reliable 823 rim set-up. I also run stans... I'm a robust 200 lbs.

The only time I've ever burped in 3 years is with a Michelin Comp 32, but I hadn't put air in it for a couple weeks. I felt the tire before the ride and it was soft! I thought, "oh well, let's see...) About 2 hours later I was going through a rock garden that had a decent crack I stuck my front wheel in (slow speed) and pbpbpbpbbp.... burpage.

I don't know what the real psi was that day, but since then I set psi around 25... (by feel of course.)
 

bullcrew

3 Dude Approved
185lb and above 22lbs - 30 preferrably towards the 30 mark.
Im 220 raw and 26 is my magic # on maxxis DHF 3c DH casings (syncros dps 32 and dt 6.1 hoops).
It avoids the sidewall roll over and squish as well as tracks spot on, it still allows rocks to contact the center of the rim depending on terrain and riding style.
I run 28-30 at tamarack, tunnel and brundige the rest of the rides have been 24-28. When running tubeless the different pressures are more noticeable than a tubed set up due to the less material between rim and outside.

 
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DirtyMike

Turbo Fluffer
Aug 8, 2005
14,437
1,017
My own world inside my head
185lb and above 22lbs - 30 preferrably towards the 30 mark.
Im 220 raw and 26 is my magic # on maxxis DHF 3c DH casings (syncros dps 32 and dt 6.1 hoops).
It avoids the sidewall roll over and squish as well as tracks spot on, it still allows rocks to contact the center of the rim depending on terrain and riding style.
I run 28-30 at tamarack, tunnel and brundige the rest of the rides have been 24-28. When running tubeless the different pressures are more noticeable than a tubed set up due to the less material between rim and outside.




Was that from when your tire let out that big ass Fart at FOntana????? That was funny ****
 

jcole

Chimp
Sep 1, 2008
6
0
Surrey, BC
My first post on ridemonky,

I set up ghetto tubeless to experiment with weight savings:

I'm 170lbs without gear
Maxxis DHF 2.35" single ply folding bead front n rear
wtb laserdisc FR rims
ghetto tubeless using stan's sealent and 16" bmx tubes (these work better than 20")

My experience:

For drops to uneven surfaces, or drops where you land on some sort of angle/rock face, the rear would burp at 25psi. I decided running 32 - 35 psi for the rear was ideal.

For trails such as A-Line which cause a lot of g-force during high speed jump takeoffs that also happened to curve slightly left or right at the peak of fork compression, the front tire would flex unpredictably and cause me to be sent off the jump slightly crooked. Keeping the front tire around 35 psi cured this, but also caused it to feel slightly harsh on brake bumps.

I think if you were running a thicker casing, it would resist some of the tire flex and perhaps not burp as easily at lower pressures. Wire bead would probably help as well.


Rolling resistance ? Who knows, went from Nevegals to the DHFs, the dhfs roll better anyways.

The good?

5 days at whistler, 2 days at silverstar, 2 days at woodlot, countless days on burke mtn and eagle mtn without a flat (but burped twice at lower psi on the rear)

The bad?

Ripped the rear dhf wide open in a high speed section of freight train on whistler. Instant flat. Had to take off tire, borrow a spare tube, drain the milky sealant install tube and baby the tire down the mountain.


My verdict:

When you're up high on the trail, sealant ****ing sucks. So much so that I have gone back to xc tubes with thick casing nevegals. The benefits of no pinch flats and losing almost a pound of weight off the bike are more than offset by the pain of getting a flat.

If you're going to do tubeless, you're trading inconveniences of pinch flats for semi-unrepairable situations, but less often. If you're doing to do it and your riding style is close to aggressive, use the thick casing tires, but say goodbye to the weight savings.
 

no skid marks

Monkey
Jan 15, 2006
2,511
29
ACT Australia
My first post on ridemonky,

I set up ghetto tubeless to experiment with weight savings:

I'm 170lbs without gear
Maxxis DHF 2.35" single ply folding bead front n rearThis is obviously not a DH worthy tyre, and you could have had the exact same problem you did with a tube. You no doubt would have flatted more often anyway, and if you added up all the time lost, I'd say you still would've been better off with the tubless set up. Tipping out sealant is the only inconvenience you suffered due to your set up Vs a tube in there.
wtb laserdisc FR rims
ghetto tubeless using stan's sealent and 16" bmx tubes (these work better than 20")Interesting, I may try this, would be lighter, but harder to cut down as a rim stripaccuratly(ghetto Pro stylee), but would be better for lazy Ghetto style and the tyre would go on a tad easier, although not seal as well by a tincy wincy bit.
When you're up high on the trail, sealant ****ing sucks. So much so that I have gone back to xc tubes with thick casing nevegals. The benefits of no pinch flats and losing almost a pound of weight off the bike are more than offset by the pain of getting a flat. I'll take performance gains when ridding over a messy inconvenience any day.

If you're going to do tubeless, you're trading inconveniences of pinch flats for semi-unrepairable situationsIf using the same tyre, you'll get the same damage, just carry a spare tube as you would running a tubed set up, you'll still get all the tubless bennefits, but you may get dirty hands:eek:, but less often. If you're doing to do it and your riding style is close to aggressive, use the thick casing tiresThis is the DH section,always use a thick cassing tyre for DH, but say goodbye to the weight savings.
DH tyres are genrally thicker walled and offer performance as well as punctture resistance.
 

davep

Turbo Monkey
Jan 7, 2005
3,276
0
seattle
My first post on ridemonky,

I set up ghetto tubeless to experiment with weight savings:

Maxxis DHF 2.35" single ply folding bead front n rear

the rear would burp at 25psi. ...
burped twice at lower psi on the rear...Ripped the rear dhf wide open in a high speed section of freight train on whistler.

I have gone back to xc tubes with thick casing nevegals. The benefits of no pinch flats and losing almost a pound of weight off the bike are more than offset by the pain of getting a flat.

If you're going to do tubeless, you're trading inconveniences of pinch flats for semi-unrepairable situations, but less often. If you're doing to do it and your riding style is close to aggressive, use the thick casing tires, but say goodbye to the weight savings.

uhhhhhh...ever stop to think that the issues that you experienced just might have a little to do with changing from DH tires to XC tires????

Next time you do some experiment of any sort, you might want to think about controlling some variables....

your experience is tire casing thickness related and has nothing to do with tubeless or tubed!!
 

no skid marks

Monkey
Jan 15, 2006
2,511
29
ACT Australia
uhhhhhh...ever stop to think that the issues that you experienced just might have a little to do with changing from DH tires to XC tires????

Next time you do some experiment of any sort, you might want to think about controlling some variables....

your experience is tire casing thickness related and has nothing to do with tubeless or tubed!!
Well you summed that a lot shorter than me:cheers:
 
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dhkid

Turbo Monkey
Mar 10, 2005
3,358
0
Malaysia
With Michelins I could run as low as 20psi NO worries. With Maxxis I tend to burp even at 30psi sometimes.
i never have had trouble with tires burping, but i definately prefer michelins casing. only if they weren't so expensive and aren't a bitch to mount up.



its weird how you guys are having trouble with tires burping and flatting, where as the minimum pressure for me is so that the tires dont fold over. think it probably comes down to rider weight.

anything below 20-21 psi, and i can make the tire fold over just doing flat corners in the car park. if the track has big side loads on the tire then i would set it higher, but never really have trouble with flats unless its a really rough course, then everyone has trouble really, tube OR tubeless.


single ply tires are fun, that 400 grams or so weight savings at the wheel makes your bike a totally different animal. not that i would ever use it for racing. i had to run 35 psi in the single pls to stop them from folding over, made the ride a bit bumpy, but was still really fun.
 

jcole

Chimp
Sep 1, 2008
6
0
Surrey, BC
uhhhhhh...ever stop to think that the issues that you experienced just might have a little to do with changing from DH tires to XC tires????

Next time you do some experiment of any sort, you might want to think about controlling some variables....

your experience is tire casing thickness related and has nothing to do with tubeless or tubed!!
Read much ? I stated exactly that in my post. I also saved a pound of rotating/unsprung mass from my bike in doing so.

Also, a DHF is not an xc tire, it's a DH tire, as labelled. It held up very well until I ripped it open in a fluke situation. FYI I have also ripped open thick casing tires.

The end result with single ply tubeless setup was overall good, but the mess of changing a tire and trying not to get everything dirty put me off the "performance" gains. Really I didn't feel any gains, but perhaps I'm not good enough to feel those over the conventional setup. Since I went back to thick casing tires and tubes, I didn't want to gain a bunch of weight back on the bike so I took off the 66's and put on a boxxer worldcup. :lighten:
 

bullcrew

3 Dude Approved
Was that from when your tire let out that big ass Fart at FOntana????? That was funny ****
Nope, did it hucking a rock chute at Big bear. Fired off the top full speed and landed mid chute (A$$ load of rocks) full speed ahead and hit a huge rock! Rode it out but had to tube it to ride the rest of the day as it wouldnt hold the tire for tubeless :D.
 

davep

Turbo Monkey
Jan 7, 2005
3,276
0
seattle
Read much ? I stated exactly that in my post. I also saved a pound of rotating/unsprung mass from my bike in doing so.

Also, a DHF is not an xc tire, it's a DH tire, as labelled. It held up very well until I ripped it open in a fluke situation. FYI I have also ripped open thick casing tires.

The end result with single ply tubeless setup was overall good, but the mess of changing a tire and trying not to get everything dirty put me off the "performance" gains. Really I didn't feel any gains, but perhaps I'm not good enough to feel those over the conventional setup. Since I went back to thick casing tires and tubes, I didn't want to gain a bunch of weight back on the bike so I took off the 66's and put on a boxxer worldcup. :lighten:


First and foremost, a single ply maxxis or any other brand tire is NOT a DH tire no matter what you name it (do you seriously believe this?? )
. Are the Mich tires for automatic transmission bikes only as they are named A/T??

This thread (in the DH forum) asked about running a tubeless set-up and pressures on a Dh bike. Your input was about your change from a DH tire with tubes to an XC tire with no tubes. Your experience has nothing to do with what the O/P was asking nor is it relevant as you have too many variable changing to be able to form any reasonable conclusion.

You have decided that tubeless is not a viable option because of your experience, but what you complain about is a factor attributable to your single ply tire choice and not due to the tubeless conversion.

Try some proper DH tires set-up correctly w/o tubes and then come back when you can make a reasonable comparison. You will still save a significant weight over a tubed set up (a pound pretty easily).
 
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