Proving low tyre pressures work in sand
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- เผยแพร่เมื่อ 3 ต.ค. 2024
- #sanddriving #tyrepressures #lowerpressure #sand #beachdriving #dunedriving
How effective are lower tyre pressures in sand, why should you lower them, what difference do reduced tyre pressures make and how far should they be lowered? All answered in this video complete with practical demonstrations! The sand might be beach, inland, dunes or whatever else - the same principles still apply, and it doesn't matter whether the vehicle is a Suzuki Jimny or a Mercedes-Benz Unimog - lower tyre pressures work the same way for both.
Post questions as comments!
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Great way to demonstrate the basics. The amount of enthusiasts that I come across who do not understand the principles and just memorize a certain number of psi is surprising!
Personally I start around 10 and go as low as 5 for the challenging climbs. But as you stated the driving style must change to avoid issues.
As always I enjoy learning from your channel 👍
Thanks Robert 👍
Robert you are without a doubt the most knowledgable off road driver I've ever seen. Been following you for some time and I can do a lot more with less now that I am educated. My vehicle has a complete recovery kit complete with winch, snatch rings, kinetic ropes and tow ropes etc. I am far more capable in this rig with knowledge than I am in a more capable rig relying only on gear. Thank you for what you do. Bought your book also. It's fantastic!
Thanks, MMG. I'm probably not the most knowlegable, but what I do have is a burning desire to figure out why things are the way they are, and then explain to people in the name of safety through education. I'd say that's my difference, not necessarily actual skill/knoweldge level. But thanks, made my coffee taste sweeter this morning :-)
The same thing can be said about first aid. It's not about the gear you carry but how you apply your knowledge. You can either carry a bandage with you wherever you go, or tear up a t-shirt and make one, it's about knowing what to do. You can give someone a grand piano, but it doesn't make them an instant Liberace. Knowledge is a wonderful thing.
I really appreciate your no-nonsense content. That goes not only for this video, definitively worth following your channel. Well done! Thank you very much.
I appreciate that!
Not only a good demo of tyre pressures , but also judicious use of momentum.
aha I have another video coming where that is explained, Principles of Sand Driving!
This video was the best explanation and visualization of this issue I have seen. Thanks -
Glad it was helpful! Please share 👍
Good, illustrative, well-explained content with no extraneous BS. Sure, entertainment orientated content can be fun, but it's great to have just pure, concentrated information.
I appreciate that! Hard balance to make sometimes :-)
I love seeing the science experiments you show us Mr Robert Pepper. I now have a greater understanding of tyre pressures in sand driving. All I knew before was very basic knowledge about lower tyre pressures are needed for sand. Thank you.
Glad to help, please share!
Another top video full of great real world demo's with easy to understand information on why and how with graphics to back them up.... just like your book that came the other day.
I'll be getting another one to give to my son and share your videos to him, he just bought a used Hilux and can learn a ton of info, just from your channel. I will be able to sleep well knowing he will be atleast well educated in theory with a book to keep him on the spot if in need.
I appreciate the work you do and putting it all together for a novice to easily understand and not feeling silly as you answer all those question in your explanations in the video.🙏👍🍻🤠
Thanks to you and your crew filming the demonstration
Our pleasure!
When it really comes down to it the general rule I have followed for the last 45 years is "Air down until the tire looks half-flat". Your tires at 10psi were a perfect example of "half flat". All of my time offroad was in an 1967 Jeep CJ-5, with 33x12.50R15 LT's. In sand I dropped down to 2-3 psi, 5-6 psi in the rocks, and only ran 6-8 psi on the pavement. Fun fact, I NEVER lost a bead over that 45 years. How you ask? Well first off the Jeep was really light, like 2000 lbs/900 kg light, plus with the tires being taller and wider with thicker sidewalls that is what pressure they needed to wear properly and hold the Jeep up. Heavier vehicles with smaller/narrower tires cant go as low, as you saw with your 265's on your Ranger with 10 psi being about the lowest you would want to go.
I did like that you actually show a perfect example of how much difference lowering air pressure can make, not many realize it can make so much difference. I have "recovered" more people than I can count by grabbing a sick and letting air out of their tires over the years.
Very true, thanks for the comment!
This description about contact area getting longer and NOT wider is true on skinny tires, but not necessarily true on wide tires. That same Ranger on 33x12.5" tires would have a "round" contact patch at 40 psi of about a 6" diameter. The tread is about 11.5" wide. However at 20 psi it would still have a round contact patch that would now have a 8.5" diameter. So it's still not edge to edge, and it is no longer than it is wide. This is one reason wide tires can feel so rough on sand.
The video is very well made
Very interesting and informative thanks ❤
the best one i watched!
Fantastic Analysis Again
Glad you enjoyed it!
Awsome vid. Nice 😊
Excellent tutorial sir!
Glad you liked it! Please share :-)
Exellent lesson👍👍👍. Thanks.
You are welcome! Please share :-)
thank you for the advice, will try this out!
You're welcome
The difference as pressures drop is staggering. I expect a wider tyre to begin will help a too e.g. getting all the way to the top without the extra momentum?
Would love to understand the differences between HT, AT and MT rated tyres in these exact circumstances too.
Questions, questions, sooooo many questions.
Thanks Robert - another very instructive video with plenty of demonstrations and clear explanations.
No, a wider tyre won't help. Check out my Narrow/Wide tyre video for why not. The contact patch/pressure ratio is about the same for HT, AT and MT unless you go to extreme muds. Watch this : th-cam.com/video/spOUcaUzIHY/w-d-xo.html
It has been my experience that there are four factors involved with how well you will perform in sand. Vehicle weight, tire width, air pressure and tread design. You want, lighter, wider, lower and less aggressive, in that order. I drove an old CJ5, 2000 lbs/900kg, with 10"/260mm wide tread at 2 psi and an open enough tread pattern that in the sand I was essentially running on the bottom of the tread and it was insane how well it did in the sand, going most placed in 2WD that most other people needed 4WD to go. Did that longer than most people here's parents have been alive. Slicks tend to be the best in sand, MT typically are the worst AT and HT being a little better, but I have seen some cases where it was the opposite.
@@daveisnothere Thanks.
Excellent info as always!
Glad you think so!
18 PSI works great for me. I dont like to go too low because then I lose too much ground clearance.
True...but the lower you go, the less you sink in so there's a tradeoff.
Thank you for sharing
🏆🇺🇲🙏🤗
Thanks for visiting
You talk funny, but I love your videos!!
I’m just kidding man!
About the talking funny, but I do love your videos. They are very educational. I have watched some of your winching videos I bet 30 times!!!!! Anyway, another great video and thanks for doing these and educating us…. At least me.
Greetings from Cocoa, FL.
Yes, my accent to North American ears sounds weird, this I know as many have pointed this out, often not as politely as yourself. On the other hand, you guys sound odd to me with y'all, anyways, howdy, soo-berr-rhoo and neee-san :-) If I could afford it I'd employ a Texan to present USA versions of my videos in a accent that works for you guys, complete with imperial measurements :-)
@@L2SFBC No way sir!
You talk fine the way you talk!
I actually dig “y’all’s” accent.
I truly was just being funny.
Well …. trying to be.
I think you would be a cool guy to hang out with.
And I do seriously enjoy your videos!!Thank you for doing them!
@@L2SFBC Oh, please, never do that. 😄
all good Otis, I appreciate your view and comments!
Awesome Video!! Like For Real
I am wondering about the same kinds of ideas with "snow" and "icy conditions" - off-road vs on-road, hard-snow vs soft-snow? Climbing hills and descending hills in the winter conditions. It almost feels like there would be some similarities between the Soft deeper snow and the Sand driving you are showing in this video. I would love to hear your or anyone's thoughts.
Oh yeah what are your thoughts about locking beads on the rims - do they still exist? That way you can go even lower on air pressure with out the tire coming off the rim?
Yes, the same goes for other terrains too but the difference will be most marked with "compression terrains" such as sand.
Yes beadlocks exist in a variety of forms and they are useful. However they may not be road-legal. They are good in competition when you have to drive fast. Less important in recreational situations when you can take more time.
Thanks for the great video, best I've seen on this subject! I wish you would have gone to 8 psi. Also, I recently bought two of your books.
Thank you SMB! Might do 8psi next time :-)
Supporter of running this, 8psi is fine as long as your going straight nothing too gnarley
Well done Robert. Have you ever made the comparisons after you are already stuck?
Thanks another great video.
No not done that. Foe the future...
Great video but why measure in Psi when using SI units for distance and speed?
Because that's the commonly used unit. Yes I know it's mixed!
Great video thanks for that, Agreed with every aspect, One question, are we saying that the sideway bagging of the tyre adds nothing to trackion in sand?
As it looks very much like in the video that the contact patch is not the only part of the tyre in contact with the sand.
It does add something but not much. More flotation, ie lower rolling resistance than traction.
Danke!
Much appreciated thank you 😊
Great work mate as usual. Can you do something similar for mud driving conditions. As I am still a bit unsure what pressures to use with deep mud...thanks ,- gregoire
Hi, I do have a video or two on mud. Similar pressures is the answer.
That's really a great video! Very well demonstrated. I do wonder/question if lowering the tire pressure changes the tread pattern? I would think so, but I have no experience in sand. Is tread pattern important at low pressures? My father and I once were forced to travel in a very nasty snowstorm. My father dropped the tire pressure for better traction. When I asked why, he responded that it cleared out the tread as it sprung back to shape with the rotation. There was a noticeable response in traction afterwards.
The increased traction would have been due to lower pressure. Yes, there is more flex in the tyre at lower pressures, but it's more centrifugal force that throws the dirt out.
Great Video. Would you lower the pressure the same for all the 4 tyres? As for Toyota Hilux, the recommended pressure for normal driving is 30 psi for front and 36 psi for rear. Incidentally do you hv experience driving to Deadvlei, Namibia Was told the last few km is very soft sand. What will be the recommended tyre pressure if u ever been there. Tks a lot.
Yes all 4 and sorry no idea re that road but if it is soft sand 30 is too high
I was wondering about the difference front a rear with different axle weight. Can you set the pressure so the contact patch length (as measured between the metal bars) is the same front and rear? Would this work at road pressure?
I’ve done some sand driving and understand tyre pressures on sand but tyre pressures on mud is a mystery to me - maybe this could be a future video!
Yes, the pressure in a tyre is in large part dictated by the load. So, more weight = more pressure required. Also, the more load = greater contact patch for a given pressure. When towing in sand for example I might run 14psi in the front and 17psi in the rear. For mud driving it's similar pressures to sand; but very dependent on the vehicle and the situation.
Excellent video ágain Robert.
What pressure would you recommend on the really shocking parts of the Birdsville track where its just sharp shale and gravel?
I've never found the Birdsville track to be shocking but I'd say 25 to 30 and cruise max 80.
I often think about how Baja Bugs get around sand dunes and they are 2wd.
Light weight, rear engined, rear drive, long-travel suspension, flotation tyres.
@@L2SFBC Yeah a very different setup for sure, and often cheese cutters on the front.
Thanks Robert, great demonstration. I have just taken delivery of a Dmax XT with 265/60/18 tyres. I will be replacing with ATs and will probably keep the wheels. In your opinion, is the 60 profile safe to lower pressures to these levels (potential wheel damage etc) or should I go to a min 65 profile? I am enjoying the fuel efficiency of the stock size and am reluctant to go any bigger than I need to.
The ideal would be to put 265/70/17s on. But you can certainly go sand driving in 265/60/18s and in sand I'd run them at 15psi happily enough. However, you need to be aware of things like rocks just under the surface of the sand. It's a risk thing.
How much is it geared down by reducing pressures?
See my latest video for that!
Hi Robert! I'm heading to Fraser Island next week in my GWM Cannon. I'm aiming for around 17psi (traction control off) to get to the ferry on soft sand. Do you think these pressures are fine for the more compact sand where the speed limit is 80kph?
Your lucky day! l2sfbc.com/what-tyre-pressures-should-i-run-on-my-4x4-when-driving-kgari-fraser-island/
@@L2SFBC Amazing, thank you :)
@@L2SFBC An update - the Cannon handled Inskip and Fraser with no issues at all! 18psi (camper tyres too), stability off, sports mode on.
Good video, but it could have been a greet video. 3 or 4 different angles of the same event doesn’t add enough to warrant the time it takes. No need to explain contact patch area multiple times. The same information conveyed in the video could have been conveyed in one third of the time.
@timothyboone5003
Maybe for you you didn't benefit from the extra but there's a million other people in the world that the extra explanations and repetitive nature may come in handy. And you know you have free will if you think you can do it better go start your own TH-cam channel create your own content and see how it goes but you don't need to be so negative I think this is an excellent video for beginners and if you're not in a beginner you want to watch it that's great but quit your whining it's a great video
Nope, no TH-cam channel for me. I sure do not have the time nor patience required for such endeavors.
I respect your opinion and understand that not everyone sees the world through the same lens that I do.
I'd say Shhh but, we can tell people this till we lose our voices but those that need this message will never get it and those that don't need this message will be the ones hearing this message. 🤣
Well, please share the video and let's try!
@@L2SFBC well don't be shy to sub and share my vids too. 🤪
@Bluelandy