Schwalbe NN blowout during install -- twice! Rim, tire or user issue?

wanger114

New Member
Hello all -- long-time lurker, first-time poster.

Curious to hear some pro opinions on this. The short version is I had two new Schwalbe Nobby Nics blow off the front rim during install -- rim appears OK and I installed several old tires successfully afterward. Rim, tire or user issue? Or just bad luck? Long version is below:

I have stock Bontrager Line Comp 30s (29s) with the OEM rim strips. I installed a NN on the rear without issue (mounted dry using a floor pump).

The front was a little bit more stubborn - I used a light amount of soapy water and eventually got the bead to set (probably around 45 psi), but as I was reaching down to remove the nozzle the tire exploded about 15 inches from my face (my ears are still ringing).

I re-mounted the tire and (very carefully) inflated but the bead was clearly deformed. I checked the rim/rim strip all the way around and everything seemed to be fine, especially at the spot where the bead rolled over. I installed the stock XR4 and rode it for a week while waiting on a new NN.

When installing the new tire yesterday, the same thing happened. This time I pumped in a more controlled fashion and never exceeded 40 psi. I watched the last 9-10" of bead slide into the rim edge, but then BOOM blowout #2. Another ruined tire.

I installed Barzos that were on there previously (tried both front and rear tires, no problems), and just re-mounted the XR4 again without issue.

Possible rim or rim strip issue? Bontrager-Schwalbe compatibility issue? Just bad luck? Just looking for some input before I blow more $ and ruin another new tire.
 

jShort

2018 Fantasy Football Toilet Bowl Lead Technician
Team MTBNJ Halter's
I think once it blows out once, it’s shot. It’ll keep happening. I had this happen years ago and Schwable warrantied the tire.
That you did it twice makes me think you should stick to different tires.
 

JDurk

Well-Known Member
If they're tubeless ready rims, why use a rim strip vs. tape? Maybe the tubeless bead isn't low enough into the side of the rim for the bead to seat.
 

Bikeworks

Well-Known Member
I did this with a Racing Ralph that was previously installed without issue over a tire insert. My thinking is that I overstretched the bead getting it on the first time, so when I went to re-install onto a different rim, it couldn't hold the bead. Mine blew off the cassette into my leg, lotsa fun.
 

wanger114

New Member
If they're tubeless ready rims, why use a rim strip vs. tape? Maybe the tubeless bead isn't low enough into the side of the rim for the bead to seat.

The internets seem to give those rim strips a resounding thumbs up. I'm kind of new to tubeless so don't have anything to compare against (only road tubeless).

I was able to get the rear tire installed pretty easily. I'm thinking just bad luck with this particular rim and schwalbes.
 

Juggernaut

Master of the Metaphor
The internets seem to give those rim strips a resounding thumbs up. I'm kind of new to tubeless so don't have anything to compare against (only road tubeless).

I was able to get the rear tire installed pretty easily. I'm thinking just bad luck with this particular rim and schwalbes.
Can u snap a picture of the tire info? Just curious what it says.

* the section in the photo I added.

image.jpg
 

TomS887

Active Member
I'm no pro, but 30psi is usually plenty for me when seating tubeless tires. I don't think I've ever gotten up near 45psi with XC or trail tires on my 29" wheels. Weird it wasn't seating for you.
 
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moray42

Merman
I'm no pro, but 30psi is usually plenty for me when seating tubeless tires. I don't think I've ever gotten up near 45psi with XC or trail tires on my 29" wheels. Weird it wasn't seating for you.
If I recall correctly the Stan’s rims specify under 40psi because of the blowout risk. Pretty sure every tire I’ve seated (schwalbe included) was done under 40 with soapy water and occasionally bouncing to help pop the bead.
 

wanger114

New Member
If I recall correctly the Stan’s rims specify under 40psi because of the blowout risk. Pretty sure every tire I’ve seated (schwalbe included) was done under 40 with soapy water and occasionally bouncing to help pop the bead.

I've read some posts of people going 50+ psi with an air compressor -- it might just be PTSD from the blowout, but that now seems really scary.

I can't find a psi tolerance for the bonti rims. You'd think "tubeless ready" would come with more installation warnings/info.

Thanks all for the input. I submitted a warranty claim -- however if they give me a new tire I'm not sure if I will risk ruining it, or any other schwalbe for that matter. Sucks cuz that eliminates a lot of choices.
 

TomS887

Active Member
Not sure if you did this, but I'd also check the rim like if you were truing it, to make sure nothing is wonky, since this happened a couple times. You can use the zip tie on your frame/fork method if you don't have a truing stand.
 

wanger114

New Member
Not sure if you did this, but I'd also check the rim like if you were truing it, to make sure nothing is wonky, since this happened a couple times. You can use the zip tie on your frame/fork method if you don't have a truing stand.

I did check that as well -- round and true, surprisingly very little wobble.

I was just thinking, maybe next time I should try the tube method?
 

Patrick

Overthinking the draft from the basement already
Staff member
I've had one car tire come off a rim on a tire machine.
Here is a little next level vid

while your ears are ringing, this should help put it in perspective.

GL with the next one - i'd think the soapy water would help set at a lower psi??

 

wanger114

New Member
I went with a Specialized Butcher (Grid Trail T9). It went on remarkably easy and mostly seated right around 22-24 psi. I went to 30 and left it, and about 10 min later heard it pop (the good kind).

Guess it was just bad luck with these Schwalbes? Haven't heard from them yet on warranty.

Thanks again all.. Happy trails.
 
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