Tubeless PSI

Maybe I’ve been thinking too much…

I’m running a 2.1" tire on my 29er, and burped a ton of sealant out a couple weeks back. I don’t know exactly what PSI I was running, but I had left it at 40, and assume it had lost ‘some’ pressure in the week or so until I took it riding.

Anyway, I reinflated to about 42-45 to avoid any further burping. I’ve run up to 45 on my 36er before without issue. But then I got to thinking that on a Muni, the tire goes through a lot more abuse :o, and this may not be a great idea.

So I guess I’m kind of stuck, I don’t know if I should drop pressure and worry about burping, or disregard the Stans label and exceed 40 psi.

I’ve had it at 45 for the last week or so, since tubeless supposedly stresses the tire bead more-so than a tube does, if I drop the PSI back down to 35, have I risked the integrity of the bead do you think?

I’ve never worried much about it until the thought crossed my mind today that the Muni thing is way more abusive than road riding.

Apologies for the paranoia.

Thanks guys.

I was thinking about going tubeless a lot within the few last days. But I can’t believe, that my setup could be converted tubeless because of the low pressure.

I run the 24x3" Duro Wildlife at about 14 to 18 psi I think … don’t know exactly, never meassured it accurately, but it should not be much more. Everywhere I read, that you can go down with the pressure going tubless. But I can’t believe it.

Now I read, that you have issues with burping at 40psi … so maybe my 14psi would never work …

I was searching reliable sources for minimum pressure for this setup but found nothing … no idea…

Nothing is wrong until its gone wrong, no?

Id say its ok. most tyres can cope with 50psi i found but unless on sealed hard surfaces i wouldnt be running that high even on tubeless.

it be hard as a brick on the trails, not really enjoyable on the bumpy bits and risk grip loss , punctures or damage of the tyre if there are thorns or metal screws or nails or whatever pops up to end the day early

My tubeless muni has maybe 400+km’s at around 35-38psi never a burp or topped up sealant yet. But it is the Hans Damp 26er Enduro tyre. Thick sidewalls, plenty of structure. its almost like they have put a strip of plastic in the sidewalls of a normal Hans.

Thanks to Ben for the insight they are a great tyre for muni due to this and im impressed and very happy with the way its gone. Solid, weight is ok, great tread, rolls, mud shedding, grips all loose or wet surfaces, smooth on sealed road its a beast of a piece of rubber.

Maybe psi for muni comes down to the tyres we choose? my old 29 wtb nano is a shocker. i think 80psi in that if it were tubeless wouldnt be enough and i wait for a rock to slice the sidewall. its meant to be a nice tyre for the commute and offroad all rounder. Just paper thin walls.

Let us know if your bead fails or any findings on what lower psi works for you.

i cant run under 30psi safely with the 2.3" enduro

Most bike riders are running 20-30 PSI, but their weight is distributed across both tires, and they have suspension.

This tire has the EXO casing on it, which is definitely thicker than normal sidewalls.

The thing is, I don’t mind the tire at that high PSI. It doesn’t feel overly hard, and rolls/climbs really well. I’m just a bit nervous about blowing a bead off. If I drop the pressure, I’d worry about burping again, but maybe I just need to pay more attention to what I ride off of and mind my technique?

My Duro is great tubeless. I’d never run down to 14 PSI, but I can run ~25 no problem, and rarely burp that one.

I don’t want to go back to tubes, because the flat protection is fantastic with tubeless.

I run my 26x3" duro tubless at 16-18 psi and have never burped a drop (6+ months of riding muni). In fact, I rarely have to add air it seals so well. The sidewall and double “lip” on that tire make it seal like a dream (once you get it on). Go for it!

Dyad?

I think that you have discovered why the Dyad isn’t recommended for tires wider than 38c. Not that you can’t run them on it, but wide tires on narrow rims have to have a lot of pressure to prevent folding/rolling. I’m pretty sure that if you fold a tire it could cause burping a tubeless setup.

On the road you are probably running higher pressure, and leaning less aggressively into the corners. Those two factors would make rolling the tire less likely.

Yeah, kind of what I was afraid of. I figured the 23mm rim width would be plenty for a 2.1" tire. That’s only just out of 2:1. Seems like MTB’s get away with it, why can’t we just be like them? :slight_smile:

I’d try running a narrower tire, but then I’d still be running higher PSI to avoid the rim hits. I guess this is why low profile tires aren’t the norm on Muni’s.

Suggestions?

I should say that I have no problem running the higher PSI, but don’t want to risk blowing a bead out either…

Well, after much deliberation, I’ve decided what I’m going to do.

Guess it’s back to the old standby, Stans fluid in tubes. That way I can run the PSI I need to and not have to worry.

What’s the best way to get oldish stans out of a tire? Also, does it have to be completely cleaned out before you put a tube back in?

Thanks.

Oh, and the Velox rim tape I had under my Stans strip is now soggy with Stans. Should I replace it?

Dump in trashcan, followed by paper towel wipe down. It does not all have to be gone. No matter how much you try, some will always remain and stick to the outside of your new tube. It’s no big deal.

Can’t speak to the rim tape for sure, but as long as it’s still adhering to the rim, I doubt that’s an issue either.

anyone ever blown a bead?

i have only by inflating an old 36er nightrider tyre. it broke the sidewall i dont remember the psi for memory and sounded like a 12ga next to my ear… scary stuff
Never in 15yrs on mtb’s or my unicycle life.

I though of the sealant in tube setup but found many tubes i can not remove the valve… My only flats have ever been pinches and tubeless they dont exist.

Im happy to burp occasionally which i found mostly doesnt happen anyway.

For the little cost of rim tape i would replace it to tidy things up, clean the rim easier and inspect for and cracks or something that doesnt belong.

My tubeless Hans enduro i put about 5psi in every month. Sometimes im not sure if that is the air i let out connecting the pump or it does actually seep out a tiny amount…?
its on a mavic ex729 rim.

Hi Killian -
What Maxxis tire do you have? Is it an Ignitor? I recently ran my 29x2.1 EXO Ignitor tubeless for a little while. I had zero issues until I experimented with it at a pretty low pressure. Dropped off a curb and POW blew it out. Nothing torn or ripped but the bead somehow managed to become unseated and all the air escaped very rapidly.

I had two things going against me:
[LIST=1]

  • The tire was pretty old, having several hundred miles on a bike first. I think this really weakend the sidewall.
  • Low PSI. [/LIST]
  • Yeah, it’s the Ignitor. I really like the tire, but I found yesterday that if I’m even a pound under 40 PSI, if I take drops at decent speed, I burp. At 40 it’s fine, but I’m not always the best about checking tire pressure before a ride.

    Sealant in tubes has proven itself to me, it’s just heavier :roll_eyes: .

    Tasmania, all setups will lose some air over time, and some tubeless setups can definitely lose 5 PSI over a month.

    I’ve not blown a bead, but I’ve had about 8" of the bead on this tire unseat for a minute, and lost at least half of my pressure.

    Not on a uni in motion, yet. (Thank God!) Blew my nightrider off the rim twice in my house (see post on other thread) - scary as hell.

    I did blow a bead while in motion on a mountain bike. It was a “known” dodgy combination of rim/tire. That one was almost funny once my heart came back into my chest. The two hikers I had passed 50 yards ago came tearing around the corner to see if I was OK. The looks on their faces were classic. None the less, it would not have been funny at all if I were not going uphill at, like, 5 mph. I test my tubeless tires really well now before I trust 'em.

    Makes me think of the time I pinched my Foss tube between the tire bead and rim. My ears were ringing for about an hour afterwards and it will definitely make your heart skip a beat or two.

    found pics from my old blowout… it was loud

    old night rider tyre, new foss tube.

    Ended as an expensive exercise that day. I like tubeless for many more reasons now!

    sigh Just got back from a ride on this uni. It was great until it wasn’t. Ended up walking a mile and a half back to my truck. No idea what caused the puncture, but the Stan’s in the tube did next to nothing. I remember crossing through some rocks on the side of the road as I was crossing it on a downhill, and hit them hard and fast before I heard the hissing.

    I’m at a loss. Perhaps my style of riding is just too agressive for a low profile setup like this?

    That sucks… Sorry to hear about your flat. At 40psi that’s I mighty effort. I will assume it’s a pinch

    I can only suggest drop the ignitior tyre… Sorry
    It’s nice a tyre tread and fairly light. I found it’s fairly light on in the walls. I used to run maxxis minion fronts they are ok but heavy but roll great. Try the Schwalbe Hans enduro it’s tried and tested. I never had 40pound in there and 99.8% sure you could run it tubeless too at 40psi or less with your riding without issues anymore ever!

    Thanks for the suggestions. I can’t imagine it was a pinch, but really have no idea. I didn’t feel the rim bottom out, but maybe I hit a rock just right.

    The Ignitor is my second tire on here. The Bontrager I was running before was even worse. The Ignitor I have has the EXO casing on it, and had the beefies sidewalls of all the tires the same size in the LBS.

    I’d go to the Schwalbe Enduro, but don’t have the room in my frame, and that’s definitely pushing it on my 23c rim.

    I think like Jtrops said (though I hate to admit it), the bottom line comes down to rim choice. If I’d gone wider, I could go with a bigger tire (or probably even the same Ignitor) and run it tubeless without issue.

    I just don’t know if I want to go through the hassle of buying another rim/spokes and building another wheel, or jut sell it.

    I’m riding the Schwalbe Hans Dampf Tubeless on my 27.5". But I have a tubeless ready rim. I’ve never had issues with it, I’ve been riding it tubeless since last year. I had a leak a few weeks ago because my tire was cracked (Schwalbe tires do not like cold temperatures) and I ended up riding below 20psi for Muni a few times, no problems at all. I normaly ride around 30psi, and 40psi when I’m on road.

    I absolutely love the tubeless setup, I can stop worrying for pinch flats, go faster and harder! :smiley: