View Full Version : Blown Bead on trXus: twice none-the-less
Jeep'nD
November 26th, 2003, 13:08
When wheelin' this weekend I managed to pop the bead on the same tire, front right on two separate occasions. I'm running 15x8 Canyons and 31x10.5 trXus. Both incidents were preceded by air loss incidents. I started at 12 psi and lost air three times before the bead went the first time. After reseating the tire with high pressure, we filled it to 10 psi. The second pop was preceded by only one loss of air incident. I also managed to lose some air in the front right.
Each time I lost air I was heading downhill and there was a sideways load on the tires because I was turning on the trail. I believe that both times the tires popped inwards I was turning the tire, on rock without moving forward, and hence making things worse. I realize now that I need to avoid turning the wheel when not moving, especially when on a grabby surface like rock.
I was wondering if this sounds like expected behavior for a tire put in these circumstances or if there may be another problem here. Afterall I did lose air from the left side as well. And running at 12 psi seems to be reasonable to me.
Comments? Suggestions? Flames?
xj92
November 26th, 2003, 13:14
1. Run a narrower rim to keep the bead seated better
2. Run a wider tire
3. Run beadlocks
4. Run higher pressure in the tires.
I run 31's on the stock 7" rims at 15psi and I've yet to pop a bead. I've heard air escape once or twice, but never enough to worry about.
Ralph
November 26th, 2003, 13:42
Popping beads is God's little way of saying you need more air.
I run 31's myself. I don't run less than 15psi. Usually I run around 18psi. Small tires give up too much ground clearance when at very low pressure.
RR3
Jeep'nD
November 26th, 2003, 14:14
Well, I found myself bouncing off or getting pushed backwards by rocks going uphill rather than crawling over them because the psi was too high. What I need is an incab deflator for going up hill and inflator for going downhill.
So what aftermarket manufacturer is up to that challenge? I thought I saw something on the board from a WPI student looking to do a locker as a project. Maybe he could create a system that would accomplish the incab auto in/deflator instead.
So, is there no-one out there that is going to flame me for turning on rocks while stopped? Do more experienced drivers avoid this, or is it not a problem for other folks?
TOZOVR
November 26th, 2003, 20:06
get a rim with a better bead surface...I ran my 31x10.5 TrXus on the AR767's (crappy rim, decent bead) at 9 to 12 psi constantly and never lost a bead.
When dealing with low traction surfaces 9 to 12 psi is completely reasonable.
I run 8psi in my 32x11.5 SSR's
Lincoln
November 26th, 2003, 20:35
How big is the bead retaining lip on your wheels. I used frustrated with BFG 32's on my stock wheels. It was around 6 psi and I wanted to run 4.
Ran my 31's at 10, 32's around 10, and my 33's at 6-8 psi on rocks. In the snow I run them as low as possible. I've put a few hundred miles on my SSR's at 12 since Moab.
Maybe the situation caused the problem. The BFG MT's were the only tires I had come completely off the rim. Slid down a hill sideways after losing the beed.
My suggestions:
Drive accordingly
Get Beedlocks
Or run the higher presure.
Lincoln
YELLAHEEP
November 26th, 2003, 20:56
I have to disagree. I can't see any reason to run anything below 15 psi when rock crawlin' with a 31" tire.
I have to assume that you're not running much over a 4" lift given that you have 31" tires so if you're airing down to 12 or even 10 psi, you're loosing damn near all the benefits having a tire that's bigger than stock.
You're right though, I can't imagine it's a good idea to turn the wheels when sitting still - with only 10-12 psi.
Get bead locks or keep the psi up higher.
HTH.
Troy
Lincoln
November 26th, 2003, 21:21
I don't think you've played with the presure enough then. Different times require different measures for sure, but most of the time I see people using too much air.
I know several people that drive with the skinny pedal. They are almost always running twice the air I am to keep the tires on the beads and I run double what a lot of other people run. Not necessarily better, just different.
Ground clearance is an issue. Personally I like the way it sticks to rocks better at the lower presure and am willing to sacrafice a some clearance.
bluexj89
November 27th, 2003, 06:30
I used to run 10-12 PSI when I had 31's and never blew a bead. Went to a 33x10.5 and lost a bead at 15 PSI (tire was too Narrow and tall.) Now I run 8-10 most of the time with the 35's and no problems. Sometimes 1 or 2 PSI make all the difference.
retard_ed_1
November 27th, 2003, 06:38
how much pressure do you guys run on the road? i got 31x9.5 bfg mt, just wondering if it is better to run lower pressure than than what the reckomend.
thanks
tim
TOZOVR
November 27th, 2003, 06:39
Originally posted by YELLAHEEP
I have to disagree. I can't see any reason to run anything below 15 psi when rock crawlin' with a 31" tire.
Why is that?
Lucas
November 27th, 2003, 07:20
Last time I had 15psi in my 31"s and I didn't lose a bead, but punctured the sidewall between a rock and my rim. I dont understand how you can run any lower than that with a small tire without shredding them up constantly.
BIG98XJ
November 27th, 2003, 14:21
a 15x8 and a 12.5 tires is the perfect combo, ive ran as low a 8psi, but I usually try to keep em at 9-10! never popped beadNAXJA
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