Here’s how to handle debeads
Debeads are very common at low pressures in sand & can happen on any tyre brand, even if they aren't BFG. Having BFGs does increase the odds of a debead situation though. The main reason why tyres debead at low pressures is because when the sidewall takes a hit on the side of a rut, or any hard section/object, there isn't enough pressure to keep the bead firmly against the lip on the rim.
What sometimes happens is that the debead doesn't happen suddenly, but the tyre goes progressively flat. This happens when the sidewalks take multiple small hits & traps sand in between the tyre & rim lip. This allows air to escape gradually without you noticing.
The first sign that you've debeaded a front tyre is when your steering goes tight, or the steering goes off centre in the case of a rear debead. It's usually only the outer sidewall that'll debead. Inner debeads are very uncommon, but they usually necessitate a wheel swap unless you've got some ratchet straps & more time.
Jacking in sand:
Changing entire wheels isn't safe in sand, especially with conventional or hi lifts. Even if you use a jack plate the vehicle can fall to the rear, front, or side (depending on where you mount the Jack). My personal preference is an air jack/bag. The vehicles weight is resting on a wider footprint vs. a regular jack. They are much quicker & predictable. If you have an IFS vehicle & are in a precarious position or where a jack can't be used, then you're in luck. Just dig under the tyre until the body of the vehicle rests on the side of the hole. Then make the hole deeper until the articulation runs out, which usually doesn't take long.
Rebeading a tyre is faster & safer than jacking, so here are the steps that I use:
Steps:
~ after the debead, try to get to level-ish ground
~ it's always easier if you have a friend handy to go through the process
~ put your airjack in place & make sure that during inflation it pushes against the tyre. Positioning the Jack is important & be careful that the top can't be punctured by sharp underbody objects. Also watch out for the hot exhaust that'll melt your bag. You can use floor mats for protection if your bag didn't come with a rubber mat.
~ handbrake up if needed, or put into Park if it's an auto.
~ get your compressor rigged up & start your engine. This is important as it pulls big amps.
~ use the compressor air to blow as much sand out from the bead & off the middle of the rim. Start cleaning from the top. A little paintbrush is a great tool as well.
NEVER use water if the sand is dry as it just makes a sludge spot at the bottom of the inner rim. ONLY use water if the sand is already wet.
Excess sand that falls into the actual tyre doesn't matter. That's Hi-Q's job on Monday.
~ once the bead is relatively free of sand, unscrew the value inner (I always carry a few spare I case I drop one in the sand).
~ get your mate to hold the airjack hose come over the exhaust pipe. Don't rev! I've been hit in the chest with one of those cones. If it's a diesel & you're the one holding the cone over the exhaust, then make sure that your mate isn't a smartass by reving to spool up the turbo so that that you get a face full of black smoke when you take the cone off.
~ guide the Jack as its being inflated
~ once the vehicle is up, dig as much sand away under the tyre so that it can the bead is in line with where it's going to need to be.
~ now that the vehicle is up, clean the bottom of the tyre bead where sand tends to settle (6 o'clock position)
~ place the compressor nozzle onto the valve with the inner removed. We do this to get air in with less resistance & because it's faster. Strong pumps work well with debeads.
~ whilst the air is flowing, pull & position the tyre against the rim until you hear the pop. 4 hands are better than 2 here.
~ after the pop, which means the tyre is in place, remove the air nozzle & screw the valve inner back in.
~ then pump the tyre again until it's hard. It's better to drive around like that for a while to allow the bead to seat properly. Then deflate to your desired pressure again later.
~ let the Jack down & job done. After practice the whole affair shouldn't take longer than 5 minutes.
You can chuck some water on to look for bubbles that indicate if you've done a good job or not.
Anyway, the above is just a guide & each to their own in terms of doing the job.
Hope this helps somebody.
. They do serve a purpose if the vehicle is at an awkward angle or when both beads are off.