36er tire blowout

Had a blowout yesterday on my 36’er.

Been riding just fine with a 29" tube in the 36’er for a year. Rode mongolia, malaysia all fine. But yesterday took the pressure up to 50 psi and she blew. Everyone at the pub thought there was some sort of uni gangland violence starting up, hahahah - the bang was incredible. (Ended up riding a trike with these fellas instead, what a great ride )

A local bike mechanic that seemed to know his stuff reckons it’s a weakness in the tyre itself and not the smaller tube size. (The blowout has left - or was caused - by a small tear in the tyre)

29" again, or go back to the heavy 36" tube? Maybe experiment with tubeless?

Why wouldn’t you use a 36" for a 36"?

Using the 29er tube saves precious weight, rotational weight, that is. I wouldn’t know, because i don’t have a 36er, but apparently low rotational weight is crucial.

Thinner tubes will always be more prone to blowouts, for the same reason balloons are.

36er tube.


Get a new tire and try tubeless?

The tire could have been defective or damaged, maybe see about a discount on replacement?

Good thing it didn’t happen while riding.

Personally, I run a 36er tube, the difference in size is just a lot to ask from a tube and not have problems. There’s a good chance that a 36er tube would have been fine.

Think heat friction, thin rubber, yeah.

My 36 tire blew out with a 36 tube. I was going about 13 mph and the bead had come off of the rim. Something felt very wrong (strange rubbing) for about 3 revs and then Bang!. I managed to end up on my feet. Replaced the tube with a 29er tube from a nearby bike shop. A week later, pumped about the tire and blam! blew out putting it in the car. The bead had separated from the tire. I think the tire was defective and the blowout had nothing to do with the tube. Anxiously waiting for a new tire to arrive.

I’ve ridden about 4000 miles on my 36" Wheel TA tire with a 29" tube. Works just fine, never had a blow out. I think the Nibus Nightrider tire is more likely to blow out at high pressure. I think the nightrider might also be a better ride, though. Take your pick.

I’ve seen enough blowouts in my life as a bike mechanic to feel pretty safe in saying that your tire was going to blow out regardless of what kind of tube you had in it. It may give you peace of mind knowing that you have a heavier tube in it. The heavier tube may take a little, very little, longer to blow through the weakness in the tire. In the end, if you have a weakness your tube will find it. What kind of tire was it? It seems like there have been quite a few posts about Nightrider tires blowing out. I wonder if it’s not something about the tires.

As for the balloon analogy, it doesn’t really apply unless you are going to put the balloon in a container that is designed to hold pressure. If you inflate any tube outside of a tire it will expand and eventually explode just like a balloon.

I don’t think a tube failure can cause a blowout. Could be very wrong; I’m no expert, but I’d assume a tire failure. The tube just pushes against it, and will the same way if it’s meant for 36 or 29" wheels.

This thread seems to have a general anti-29"-for-36er vibe. For me, running a 29" tube has a real, noticeable effect. I feel like I have more control and endurance. Not had a problem (apart from pinching one trying to get the tire over it) after about a year including a fairly big tour.

Just to play devil’s advocate here for a moment, at what point would you consider a tube too small for a 36er tire, and thus present a a very definite [tube] blowout risk, if any? A 26er tube, 24" tube? If you could stretch those enough to go onto a 36er rim-and a 26er should stretch enough-would 29er tube proponents assume it would be just as resistant to a blowout as a standard 36er tube, and also save even more precious rotational weight? If not, why?

Good point. Actually that makes me want to try smaller tubes. I’ll take a guess at the answer to your question: the risk isn’t blow-outs. Maybe they just pop or otherwise fail inside the tire?

That makes me think of something else though: I’ve seen blow-outs caused by tubes getting stuck under the tire’s bead before inflation. I know that it’s harder to get a 36" wheel together with a 29" tube, and specifically I’ve had to pay special attention to make sure the tube is clear of the beads. Maybe 29" tubes can actually be considered to cause more blow-outs simply because they’re easier to install wrong?

Still seems like an unlikely explanation for the thread’s issue; I think installation errors normally show themselves while or right after being inflated.

I should learn to read.

Suede, if I’m reading your post right, it blew as you were pumping it up?

Maybe then it could have been caused by the tube being under the bead, and maybe being a smaller tube made that more likely.

Pump up a tube without installing it in a tire. If it explodes before it reaches the volume of the tire you want to put it in then it is far too small to be of any service. If it inflates to a larger volume than the intended tire it will be constrained by the tire, and won’t blowout unless there is a weakness in the tire or the mount.

If you push it to a ridiculous level, you run into problems with the membrane leakage. This is the air that leaks through the rubber itself, and is worse as the rubber gets thinner, and the pressure gets higher. This won’t be a catastrophic failure, but a slow leak. This is the reason my road bike needs to have the tires inflated before each ride. I run my coker at 3 bars, or about 40 psi. I haven’t noticed any poorer air retention with my 29 tube vs. a 36. I suspect that the pressure is still not high enough to make a big difference.

It may work to use a 26" tube, but it’s already more difficult to mount a 29. As the diameter of the tube gets smaller it will only get more and more difficult to mount without pinching the tube or seating the tire on the tube instead of the rim (causing the tire to be blown off the rim). The 29 may not be the smallest size that works, but it is not too difficult to mount, and works well. It’s also about $15 cheaper than a 36" tube.

I honestly don’t know why they don’t make a lighter weight 36" tube. For now I have no problems running a 29, and if I ever have a blowout I will not question even for a moment if it was the tubes fault. I have seen a lot of blowouts from sewups, straight sided rims, and hook bead rims. I have never seen one that looked like it was the fault of the tube. I have seen some from poorly seated tires or too much pressure, and I have seen a lot from damaged or defective tires.

If the tube you were using is salvagable, then use it to go tubeless. If not, get another tube and go tubeless. Trust me tubeless is a huge pain to get up, but if you pull it off it’s amazing.

ONly time I ever had a 36er blow out on me was her maiden voyage with the stock 36" tube in the tire. I am sure that the blow out was caused by the tire not being seated properly on the rim and have not had a problem with the tire since.

Shortly after I got the 36er I switched to a 29" tube. worked great, no problems. More recently I tried to use some 26" DH tubes to get a bit more pinch resistance than the 29" tube but not the massive weight of the 36" tube. first one busted when I was stretching it out in preparation to mounting the tire. The second one mounted OK but felt weird at low pressures, I think that it did not stretch to fill the tire good enough to feel right.

I really don’t think that a tube can cause a blowout unless it is under the bead preventing the tire form seating properly (which is a bit harder with an undersized tube) Your tire was either not seated properly or damaged/defective.

If you have had the 29er tube in it for as many kms as you have, there is clearly no inherent weakness there.

However I agree that if you get a pin style puncture, a 29er tube is more likely to catastrofically fail than a 36er tube.

This is the reasoning why I chose to go tubeless, as I often ride in areas where there are lange numbers of prickles.

It was certainly hard, as the nightrider tyre is very tight on the rim, but I cant imagine anything else. Much lighter, and a nice, springy ride!

Having said that ,my first tubeless nightrider blew off the rim (after about 600km of mostly rough dirt roads) , but I believe that this was caused by the bead breaking in the tyre. (it is difficult to determine if it was the cause or effect) I have a new tyre on it now (tubeless again) and have no problems so far.

The first time I rode it, I rode through a big patch of caltrop, which would have been the end for any tubed tyre. I got some slime showing throught the tyre and thats it.

If you search on this site, you will find a number of others who have had issues with nightriders blowing of the rims, and blowing out through tears, I am sure there are others too, ie I have never posted about it yet. I never posted because I figured I was using it outside of its design.

If you want a hand to fit it up, PM me. I may be able to pop down and give you a hand. I bet it is easier with two people. Other than that , I might be able to teach you some new words! You can even try my wheel to see if you think it feels different to the 29er tube, to see which way you want to go.


I remember a very special 36" light tube under testing during Mongolia …

The only flats I have ever had on my Coker were goat head thorns. From your description I think that would qualify as a “pin style” puncture. If we go back to the balloon analogy think about what happens when you put a piece of tape on a balloon and pierce it with a needle. That is similar to what will happen to your tube as it is reinforced by the tire.

I have never, ever, seen a blowout that looked like it was caused by a tube. I honestly have no idea how many flats I have fixed, and out of them the number of blowouts. In ten years working as a bike mechanic I saw my fair share.

I also live in an area with a ridiculous number of thorns on the roads. Tubeless is interesting. I hate fixing flats, and this could be just the ticket. Out of curiosity, how much does the tubeless setup weigh compared to the standard 36 tube? I wonder about weight more to have a point of comparison with my 29" tube setup. I suspect that the tubeless conversion may be about the same, or a little heavier. On the other side I would guess that it might have a livelier road feel like a cotton sewup on a road bike.