BajaNomad

Why lowering tire air pressure really works

John M - 10-8-2018 at 03:03 PM

This link is found on the "Expedition Portal" site. In the relatively brief article the author explains his take on the benefits and why's of lowering air pressure when off-road. It may not be just as you think (if he is correct). As you read through the article, it refers to a couple of photos that didn't come through on the link, but they are easy to imagine.

John M

https://expeditionportal.com/the-lowdown-off-road-tire-press...

TMW - 10-8-2018 at 07:03 PM

Sounds good to me. Whether it is wider or longer as long as it works.

gnukid - 10-8-2018 at 08:14 PM

John M ima ask you don't you want higher pressure on the roads and lower pressure on the dirt?

4x4abc - 10-8-2018 at 08:31 PM

here is everything you need to know about airing down (start with the driver)

http://4x4abc.com/jeep101/soft-sand-deflate.html
http://4x4abc.com/jeep101/soft-sand-turn-straight.html
http://4x4abc.com/jeep101/soft-sand.html

BajaMama - 10-9-2018 at 05:28 AM

Yep, all vehicles in our 4x4 club air down, then air up before and after runs. I just got a mini compressor so maybe I'll air down for the long haul out the road to Punta Chivato (kidding, never need to before...). But yes, more surface contact is the key.

John Harper - 10-9-2018 at 06:26 AM

Quote: Originally posted by BajaMama  
Yep, all vehicles in our 4x4 club air down, then air up before and after runs. I just got a mini compressor so maybe I'll air down for the long haul out the road to Punta Chivato (kidding, never need to before...). But yes, more surface contact is the key.


I aired down on the miles of graded roads in the Copper Basin of Idaho. It just makes the truck ride softer and not have a tendency to "skitter" around (as shown in 4x4abc's attachment).

John

4x4abc - 10-9-2018 at 06:48 AM

I found that on Baja dirt roads reducing tire pressure from around 30 psi to20 psi will completely eliminate the risk of flat tires.

Going up in pressure would increase the risk of flat tires.

Always think of a fully inflated birthday balloon - a coarse finger nail will make it explode. A limp balloon does not even react to something sharp.

David K - 10-9-2018 at 07:15 AM

I greatly reduced flats from sharp rocks at 20 psi, down from the 34 psi street pressure. My air pump connects direct to the battery (MV-50) and only takes 2.5 minutes to refill each tire, which is 3 times quicker than the pumps that plug into the cigarette lighter.

4x4abc - 10-9-2018 at 07:17 AM

anything smaller than an MV-50 is not worth having.
Main reason - when you most need them, cheap plug in compressors will have quit working.

BajaNaranja - 10-9-2018 at 08:22 AM

Keep in mind that ideal tire pressure for offroading depends on a few other factors, like:

Weight / load: A Ford F350 with a cab over camper will have a tremendous amount of weight compared to a Toyota Tacoma, and ideal air pressure for offroading has a lot to do with weight on tires. So 20-30 psi may be a good round about target to try for most light vehicles, but if you are dealing with heavy load, slowly decrease pressure and watch sidewall deformation.

Type of tires: All terrain or off road tires often have beefier sidewalls with additional tire plys and are much heavier, versus street tires which are constructed to be lighter and to provide greater fuel efficiency on the highway. Obviously an all terrain or off road tire, with a beefier carcass, is going to absorb a lot more abuse and handle lower air pressure better in an off-road setting than a street tire.

Type of terrain: There are plenty of roads in Baja where there's jagged lava rock embedded in dirt; might not want to expose too much sidewall in such areas, as lava rock can slice sidewalls with ease. Versus pure sand, where lower tire pressure is better.

As always, take on advice while exercising your own judgement, and ask a saltier vet for their take, if in doubt.

David K - 10-9-2018 at 08:37 AM

Agreed, a % of the street pressure for deflation amount may be a better way to cover both heavy truck tires vs light truck or car tires. For example, 30% for dirt roads and 50% for deep sand.

AKgringo - 10-9-2018 at 10:15 AM

Check your tire pressure gauge as well! I have found significant differences in readings when I compare them against each other.


The PSI will also change a bit with temperature and sidewall flexing.

JZ - 10-9-2018 at 10:51 AM

Quote: Originally posted by AKgringo  
Check your tire pressure gauge as well! I have found significant differences in readings when I compare them against each other.


The PSI will also change a bit with temperature and sidewall flexing.


Use the gauge on your dashboard.

msteve1014 - 10-9-2018 at 01:15 PM

Quote: Originally posted by JZ  
Quote: Originally posted by AKgringo  
Check your tire pressure gauge as well! I have found significant differences in readings when I compare them against each other.


The PSI will also change a bit with temperature and sidewall flexing.


Use the gauge on your dashboard.


Too funny. I just got an email telling me my tires are low.
New trucks, huh?

JZ - 10-9-2018 at 01:52 PM

Quote: Originally posted by msteve1014  


Too funny. I just got an email telling me my tires are low.
New trucks, huh?


Mine gives you the instantaneous length of your tire footprint. So you can tell how much air to let out.

Unfortunately, it doesn't yet have a button to deflate to said pressure/length - yet.

4x4abc - 10-9-2018 at 02:24 PM

here are the rules for tire deflation:

off-road (meaning leaving pavement) 1/3 less than street pressure
if street was 30, now it is 20
mud, sand and snow 2/3 less than street pressure
if street was 30, now it is 10
emergency (about to get swallowed at Malarrimo) 50% less than mud, sand and snow
if MSS was 10, now it is 5

if you have tires with a low aspect ratio (like 275/50 or 285/30) have a tow truck follow you
if your tires do not have a light truck designation (like LT275/70 etc) avoid dirt roads in Baja - short stretches like around Chapala are OK when driven carefully.

I know you all have your personal buts, ifs and whens - but they dot affect theses rules.

And no, your tire will not come off the wheel when at low pressures like 10 or 5. Beadlocks (metal rings that bolt your tires to the wheel) were invented for drag racing and serve a purpose there. Then the competition offroaders discovered them. Because they drive like maniacs, they need them too.
You will only need them if you combine 10 psi with donuts at the beach.
No sane driver will ever need beadlocks.
However, they make you look semi professional.

JZ - 10-9-2018 at 04:12 PM

Quote: Originally posted by 4x4abc  
here are the rules for tire deflation:

off-road (meaning leaving pavement) 1/3 less than street pressure
if street was 30, now it is 20
mud, sand and snow 2/3 less than street pressure
if street was 30, now it is 10
emergency (about to get swallowed at Malarrimo) 50% less than mud, sand and snow
if MSS was 10, now it is 5

if you have tires with a low aspect ratio (like 275/50 or 285/30) have a tow truck follow you
if your tires do not have a light truck designation (like LT275/70 etc) avoid dirt roads in Baja - short stretches like around Chapala are OK when driven carefully.

I know you all have your personal buts, ifs and whens - but they dot affect theses rules.

And no, your tire will not come off the wheel when at low pressures like 10 or 5. Beadlocks (metal rings that bolt your tires to the wheel) were invented for drag racing and serve a purpose there. Then the competition offroaders discovered them. Because they drive like maniacs, they need them too.
You will only need them if you combine 10 psi with donuts at the beach.
No sane driver will ever need beadlocks.
However, they make you look semi professional.


Looks good except for the 1/3 off for general dirt driving. We typically run 34 on E load tires. Where it is 60-65 on the street. So closer to 45% less.





[Edited on 10-9-2018 by JZ]

4x4abc - 10-9-2018 at 04:27 PM

I always like individual adjustments

4x4abc - 10-9-2018 at 04:59 PM

by the way, lowering tire pressure does not increase traction
in fact, you have the same traction with deflated tires as with 100 psi (less weight per square inch, but more of it vs more weight per square inch but less of it)
weight increases traction
ever follow a loaded logging truck down the mountains?
you will have a hard time following him
lotsa pounds per square inch
lotsa traction

so the advantage of lower pressure in sand is less resistance
the "hill of sand" you are running against is smaller with less pressure
thus less resistance

on dirt roads the advantage is increased flexibility
the tires now mold around ground contours
like a flexible hand grabbing outcroppings during mountain climbing
the larger footprint also guarantees more points to hold on to
so more tire pressure gives you more traction (per square inch) but a smaller footprint and thus less opportunity to grab the ground
that is why we opt for less pressure

on the negative side:
rolling resistance goes up, with it gas consumption
ground clearance will be reduced
side wall is more exposed and less talented drivers might have side wall nicks (most likely right rear)

why right rear?
like in real life, people tend to avoid problems - they steer around them
in a car that usually works fine for the front tires
but since the rear tires follow a different path, one of the rear tires will get bruised
right rear because it is the farthest away from the driver and the most difficult to place (left rear in Australia)
the way out?
take on problems!
drive o
ver the obstacle - you are always telling your friends how much ground clearance your truck has - use it!

ingrown rocks on a trail or dirt road signal their danger to all drivers way ahead
they always have a very black side
blackened by bruised side walls
once you spot them, it is your chance to behave differently
you probably won't - but at least you read about it



JZ - 10-9-2018 at 05:06 PM

Biggest benefit of airing down is a MUCH more comfortable ride.

willardguy - 10-9-2018 at 05:29 PM

guru of offroading= harald
guru of trailriding = larry
gracias to both:yes:

woody with a view - 10-9-2018 at 06:23 PM

4lo and 10 psi should get any self respecting trail blazer out of 95% of trouble.

4x4abc - 10-9-2018 at 07:11 PM

Quote: Originally posted by woody with a view  
4lo and 10 psi should get any self respecting trail blazer out of 95% of trouble.


the purpose of 4x4 is to avoid trouble.

I had a government agency some years ago that wanted multi day recovery training for their employees.
I convinced them to divide the training into avoiding to get stuck first and then what to do after you effed up.


[Edited on 10-10-2018 by 4x4abc]

4x4abc - 10-9-2018 at 07:19 PM

here is a word on pressure gauge accuracy.

A gauge that goes up to 100 psi will give you very little accuracy between 0 and 20
A gauge that goes up to 60 psi will give you very little accuracy between 0 and 10

For serious Baja travelers a 0-30 gauge is a must. Most will need 2 gauges then.

A word of caution - if your tires are at 35 psi and you use your 0-30 gauge, it will die instantly. Done that a few times.
For 5 psi at Malarrimo a precision gauge is a must.


JZ - 10-9-2018 at 07:35 PM

Quote: Originally posted by 4x4abc  
here is a word on pressure gauge accuracy.

A gauge that goes up to 100 psi will give you very little accuracy between 0 and 20
A gauge that goes up to 60 psi will give you very little accuracy between 0 and 10

For serious Baja travelers a 0-30 gauge is a must. Most will need 2 gauges then.

A word of caution - if your tires are at 35 psi and you use your 0-30 gauge, it will die instantly. Done that a few times.
For 5 psi at Malarrimo a precision gauge is a must.




A good digital gauge that goes 0 to 80 is a must. That plus the gauge on your dash board is the winning combo.



[Edited on 10-13-2018 by JZ]

advrider - 10-9-2018 at 07:43 PM

In the rocks I run 6-10 on my jeep and it works good, with bead locks! Less air is your friend..

PaulW - 10-10-2018 at 08:55 AM

Excellent
Quote: Originally posted by 4x4abc  
here is everything you need to know about airing down (start with the driver)

http://4x4abc.com/jeep101/soft-sand-deflate.html
http://4x4abc.com/jeep101/soft-sand-turn-straight.html
http://4x4abc.com/jeep101/soft-sand.html

PaulW - 10-10-2018 at 09:08 AM

My latest mud venture I used 4lo and 2nd gear. Very low throttle setting and it worked. Extra throttle and all I got was tire spinning. A special circumstance due to the deep mud.
Harald, I was running 20psi. Should I have been lower or go up to 32?
I was not about to change the pressure due to the great difficulty and horrible mess. No way to plan ahead in this case.

4x4abc - 10-10-2018 at 09:40 AM

messy hands are cheaper than a tow truck
get out and air down!
airing up and down in a 4x4 is the most important tool/technique of all
all the "tools" you hang on the outside of your vehicle show that you are full of air

and yes, in mud I would definitely have run (or aired down to) 10 psi or less
just enough gas to get the car moving
all lockers, if you have them (no 4x4 should be without lockers)

if 10 psi still give you slipping tires go to 5 psi

2nd gear low range is old English Voodoo
it accomplishes nothing
in terms of power to the wheels it is equivalent to 1st gear high range (can vary wildly with make of truck)
but 2nd low was a better choice than 1st low

DawnPatrol - 10-10-2018 at 06:15 PM

Harold;
I have a F250 SuperDuty 4x4 diesel. I have LT 265/70 's Load rated E rated to 80#
I usually run them around town at 60

How low should I go on dirt trails that are a mix of sand and dirt?

Thanks
Alan in San Diego

JZ - 10-10-2018 at 06:32 PM

Quote: Originally posted by DawnPatrol  
Harold;
I have a F250 SuperDuty 4x4 diesel. I have LT 265/70 's Load rated E rated to 80#
I usually run them around town at 60

How low should I go on dirt trails that are a mix of sand and dirt?

Thanks
Alan in San Diego


35. It will make a world of difference.

Put some good shocks on it too. Kings have been awesome for me. I snapped 2 of the stock shocks in half.





[Edited on 10-11-2018 by JZ]

4x4abc - 10-10-2018 at 07:39 PM

Quote: Originally posted by DawnPatrol  
Harold;
I have a F250 SuperDuty 4x4 diesel. I have LT 265/70 's Load rated E rated to 80#
I usually run them around town at 60

How low should I go on dirt trails that are a mix of sand and dirt?

Thanks
Alan in San Diego


every truck and every tire is different
to apply the1/3 rule (above) you need to find your true "normal" pressure
the one you run around town
run the chalk line test first, that will give you normal pressure
many examples on youtube - https://www.youtube.com/results?search_query=tire+chalk+line...
that test is done in 10 minutes (200 ft are sufficient to see the wear pattern)

you will have to establish "normal" for loaded and empty bed

for long fast freeway trips add 10 to 15 psi
for off-road follow the 1/3 rule

let us know what you find out

JZ - 10-10-2018 at 07:48 PM

35

4x4abc - 10-10-2018 at 08:09 PM

Quote: Originally posted by JZ  
35


front and rear? I doubt it.

DawnPatrol - 10-10-2018 at 08:49 PM

Quote: Originally posted by 4x4abc  
Quote: Originally posted by DawnPatrol  
Harold;
I have a F250 SuperDuty 4x4 diesel. I have LT 265/70 's Load rated E rated to 80#
I usually run them around town at 60

How low should I go on dirt trails that are a mix of sand and dirt?

Thanks
Alan in San Diego


every truck and every tire is different
to apply the1/3 rule (above) you need to find your true "normal" pressure
the one you run around town
run the chalk line test first, that will give you normal pressure
many examples on youtube - https://www.youtube.com/results?search_query=tire+chalk+line...
that test is done in 10 minutes (200 ft are sufficient to see the wear pattern)

you will have to establish "normal" for loaded and empty bed

for long fast freeway trips add 10 to 15 psi
for off-road follow the 1/3 rule

let us know what you find out


OK I will try it out and let you know. I agree my truck bounces a bunch with no load, rides like a dream when loaded (thats at the 60#)

Harald... sorry for the misspell!



[Edited on 10-11-2018 by DawnPatrol]

bajatrailrider - 10-11-2018 at 04:33 PM

JZ you and bikers will get a kick out of this. Years ago two of us on 87 CR500 67hp. Where riding in a group of my brothers friends we did not know they where factory Honda riders. All riding Xr250s built so they had a hill climb type trail. S turns no run no traction steep. The two of us on Cr500s already only had 6 psi in the tires. No worry we where thinking the little XRs are no match for our smokers. Well 6 of them went up first try. Friend hit it 5 times could not make it all little bikes at top having good jokes about the CR500s. I tried 3 times got very tired drink all my water. Told other Cr rider watch this I removed valve stem rear tire put it in pocket. Went up it blazing fast made the Xr riders run for cover. Other Cr rider did same right up. We pulled out our cycle pump put valve stem back up 6psi and away we went.

norte - 10-11-2018 at 04:45 PM

Quote: Originally posted by bajatrailrider  
JZ you and bikers will get a kick out of this. Years ago two of us on 87 CR500 67hp. Where riding in a group of my brothers friends we did not know they where factory Honda riders. All riding Xr250s built so they had a hill climb type trail. S turns no run no traction steep. The two of us on Cr500s already only had 6 psi in the tires. No worry we where thinking the little XRs are no match for our smokers. Well 6 of them went up first try. Friend hit it 5 times could not make it all little bikes at top having good jokes about the CR500s. I tried 3 times got very tired drink all my water. Told other Cr rider watch this I removed valve stem rear tire put it in pocket. Went up it blazing fast made the Xr riders run for cover. Other Cr rider did same right up. We pulled out our cycle pump put valve stem back up 6psi and away we went.


ANd the valve stem/tube did not pinch.

JZ - 10-11-2018 at 06:10 PM

Quote: Originally posted by bajatrailrider  
JZ you and bikers will get a kick out of this. Years ago two of us on 87 CR500 67hp. Where riding in a group of my brothers friends we did not know they where factory Honda riders. All riding Xr250s built so they had a hill climb type trail. S turns no run no traction steep. The two of us on Cr500s already only had 6 psi in the tires. No worry we where thinking the little XRs are no match for our smokers. Well 6 of them went up first try. Friend hit it 5 times could not make it all little bikes at top having good jokes about the CR500s. I tried 3 times got very tired drink all my water. Told other Cr rider watch this I removed valve stem rear tire put it in pocket. Went up it blazing fast made the Xr riders run for cover. Other Cr rider did same right up. We pulled out our cycle pump put valve stem back up 6psi and away we went.


Funny.

My best hill climb memory was at Jawbone off 395 North of Mojave.

Was riding a junker bike. Hit a super steep hill full speed, got to the lip and jumped off the bike. Landed on my feet and the bike flew another 20 yards or so into a big bush. Looked down at a group of friends and raised my hands in the air.

I might have had a beer or two before that.

bajatrailrider - 10-11-2018 at 08:21 PM

Jawbone canyon yes that's is where it happened. To answer why no tube pinch with zero air. It was only a 500ft climb and we use 4mm thick tubes. With two rim locks on rim.

motoged - 10-11-2018 at 08:48 PM

For my BC trail riding/single track/cross country on my 450 I have traditionally used 11-14 psi front and 10-12 psi for rocks/roots/mud/gravel and UHD tubes, and single rim locks front and back.

Doing multi-day rides w/camping gear (Giant Loop Coyote bag) in Baja I have traditionally gone to 16-20 front and about 15 +/- rear with Slimed UHD tubes.

Riding a few years ago with a few Nomads, the bike guy took me into the dunes and I struggled as that type of sand has been my bane. He suggested 8 psi front and same or lower in back....and being used to avoiding pinch flats i was hesitant. I tried 10 front and 8 back and felt the difference....and played with nothing lower than 8.

Spending a lot more time with lower psi's in the sand when I can....and have started to enjoy it.

A convert.



[Edited on 10-12-2018 by motoged]

JZ - 10-11-2018 at 11:13 PM

Quote: Originally posted by motoged  
For my BC trail riding/single track/cross country on my 450 I have traditionally used 11-14 psi front and 10-12 psi for rocks/roots/mud/gravel and UHD tubes, and single rim locks front and back.

Doing multi-day rides w/camping gear (Giant Loop Coyote bag) in Baja I have traditionally gone to 16-20 front and about 15 +/- rear with Slimed UHD tubes.

Riding a few years ago with a few Nomads, the bike guy took me into the dunes and I struggled as that type of sand has been my bane. He suggested 8 psi front and same or lower in back....and being used to avoiding pinch flats i was hesitant. I tried 10 front and 8 back and felt the difference....and played with nothing lower than 8.

Spending a lot more time with lower psi's in the sand when I can....and have started to enjoy it.

A convert.



[Edited on 10-12-2018 by motoged]


Where's the bloody pics and stitches to screw up the thread?

4x4abc - 10-12-2018 at 08:56 AM

"steep climb" is a good topic for airing down
you won't find steep climbs on any build road - engineers rarely make them steeper than 10% (which makes another good discussion - 10% is a lot less than 10 degrees)
but once you leave man made trail you may encounter some incredibly steep stuff
Widowmaker is a good example - not so steep, bumpy
the climb on the turquoise mine trail is another one

since the center of gravity of your truck changes when tilted up, the rear tires carry substantially more weight
the front axle carries a lot less weight
weight is important for traction
with a shifted center of gravity, the front has less traction then the rear (if at equal psi)

visually, your front tires look like they have 50 psi even though you aired down 10 for that rough trail
your rear tires look like they have 3 psi
that visual actually made me think about tire pressure on really steep climbs

so here is what you do
leave the rear at 10 and reduce the front to half (5psi)
of course you can still run at the hill, kick up dust with slipping and spinning tires
or make it look easy

David K - 10-12-2018 at 04:45 PM

To add to Harald's excellent post about the front tires needed less air than the rear on steep climbs due to the center of gravity shift to the back, please (if your 4x4 is so equipped) also USE YOUR LOCKERS or TRACTION CONTROL to prevent the one tire spinning on each axle!

Spinning tires tear up the roadbed, get you nowhere, and stresses your vehicle.

I can't tell you how I roll my eyes when I see a four-wheeler not use his lockers and then spins tires or makes a friend pull him because he won't use the locking differential [which is less, not more stressful on the vehicle].

JZ - 10-12-2018 at 05:47 PM

Quote: Originally posted by David K  
...please (if your 4x4 is so equipped) also USE YOUR LOCKERS or TRACTION CONTROL to prevent the one tire spinning on each axle!

Spinning tires tear up the roadbed, get you nowhere, and stresses your vehicle.

I can't tell you how I roll my eyes when I see a four-wheeler not use his lockers and then spins tires or makes a friend pull him because he won't use the locking differential [which is less, not more stressful on the vehicle].


Get a Chevy/GMC. No need to worry about that silly stuff.


[Edited on 10-13-2018 by JZ]

4x4abc - 10-12-2018 at 06:08 PM

you are right - physics don't apply to Chevy/GMC

mtgoat666 - 10-12-2018 at 06:34 PM

Quote: Originally posted by 4x4abc  

you won't find steep climbs on any build road - engineers rarely make them steeper than 10%


Poppyc0ck!



[Edited on 10-13-2018 by mtgoat666]

JZ - 10-12-2018 at 06:41 PM

Quote: Originally posted by 4x4abc  
you are right - physics don't apply to Chevy/GMC


The point of that post, you missed it my friend.

bajatrailrider - 10-12-2018 at 09:50 PM

Another big part of trail bike riding . When you use stiff wall desert tires on your Moto. Very poor choice for trail riding as even with 2psi no sidewall bludge . With those tires 20psi or 2 psi tire feels the same. Hard as rock little hook up so if your not a racer . Stay clear of those tires unless you just ride car dirt roads.

JZ - 10-12-2018 at 10:27 PM

Quote: Originally posted by bajatrailrider  
Another big part of trail bike riding . When you use stiff wall desert tires on your Moto. Very poor choice for trail riding as even with 2psi no sidewall bludge . With those tires 20psi or 2 psi tire feels the same. Hard as rock little hook up so if your not a racer . Stay clear of those tires unless you just ride car dirt roads.


I have never aired down our bike tires. We always run at 10 to 12 psi. You'll have to teach me about pressure on our bikes.

PaulW - 10-13-2018 at 06:11 AM

Harald Wrote

every truck and every tire is different
to apply the1/3 rule (above) you need to find your true "normal" pressure
the one you run around town
run the chalk line test first, that will give you normal pressure
many examples on youtube - https://www.youtube.com/results?search_query=tire+chalk+line...
that test is done in 10 minutes (200 ft are sufficient to see the wear pattern)

you will have to establish "normal" for loaded and empty bed

for long fast freeway trips add 10 to 15 psi
for off-road follow the 1/3 rule

let us know what you find out[/rquote]
====
Good method above.
My method works very well , but is much more difficult.
1) I call the tire company and get the load vs tire pressure
2) I go to the scales and get the weight for each axle for loaded and unloaded condition.
3) Inflate the tires according to the load/pressure graph. For the 1 ton truck I add 5 psi for conservatism. For lighter duty rig I use the chart without a tweak.
The result after wearing out 4 sets of tires is they wear evenly until worn out. Nice because the ride is much smoother for the HD truck.
My method work just as well far a car or an SUV or a light duty truck.
FYI, my 1 ton diesel front pressures were set at 55 psi loaded or unloaded and the rear pressure was 45 unloaded and 65 for my heaviest load. Don't use my numbers every truck will be different.

PaulW - 10-13-2018 at 07:19 AM

Well written Harald, and certainly accurate.
Now days there are digital gauges that give the best accuracy. Way better than any mechanical gauge which are very inaccurate except at mid range pressures.
The best choices based from various testing organizations are Accutire models MS-4021R ($10) or MS-4400B ($7). (Search for current best price).
Specs for the 4021 are 0-150 psi range in 0.5 increments with accuracy of +/-0.05psi over the whole range.
The 4400B has been my choice for many years, but the 4021 is the latest model. Hard for get complete specs on the old 4400, but it should be the similar to the 4021 except it 4400 is 5-99psi range and 0.5 psi increments. Consumer reports rates the two gauges the same. I use my 4400 to verify my airbags at 5psi and always get consistent readings.
Anyway it is such a bargain to go digital with much better accuracy and the mechanical versions are no longer desirable.
====== ===
Quote: Originally posted by 4x4abc  
here is a word on pressure gauge accuracy.

A gauge that goes up to 100 psi will give you very little accuracy between 0 and 20
A gauge that goes up to 60 psi will give you very little accuracy between 0 and 10

For serious Baja travelers a 0-30 gauge is a must. Most will need 2 gauges then.

A word of caution - if your tires are at 35 psi and you use your 0-30 gauge, it will die instantly. Done that a few times.
For 5 psi at Malarrimo a precision gauge is a must.


mtgoat666 - 10-13-2018 at 08:01 AM

load tables are easiest way to determine proper air pressure. The tables are not available on line, but any tire shop has them and will let you look up.
In the time you are waiting at tire shop for tire installation, you can review the load tables :light:

Here is how to use load inflation tables;
https://www.toyotires.com/media/2125/application_of_load_inf...

I tried to look up an astm or industry standard for the chalk test, couldn’t find it :lol:

[Edited on 10-13-2018 by mtgoat666]

PaulW - 10-13-2018 at 09:20 AM

Goat, Good job finding load tables

bajatrailrider - 10-13-2018 at 07:42 PM

Quote: Originally posted by JZ  
Quote: Originally posted by bajatrailrider  
Another big part of trail bike riding . When you use stiff wall desert tires on your Moto. Very poor choice for trail riding as even with 2psi no sidewall bludge . With those tires 20psi or 2 psi tire feels the same. Hard as rock little hook up so if your not a racer . Stay clear of those tires unless you just ride car dirt roads.


I have never aired down our bike tires. We always run at 10 to 12 psi. You'll have to teach me about pressure on our bikes.

bajatrailrider - 10-13-2018 at 07:47 PM

Quote: Originally posted by bajatrailrider  
Quote: Originally posted by JZ  
Quote: Originally posted by bajatrailrider  
Another big part of trail bike riding . When you use stiff wall desert tires on your Moto. Very poor choice for trail riding as even with 2psi no sidewall bludge . With those tires 20psi or 2 psi tire feels the same. Hard as rock little hook up so if your not a racer . Stay clear of those tires unless you just ride car dirt roads.


I have never aired down our bike tires. We always run at 10 to 12 psi. You'll have to teach me about pressure on our bikes.
. On my above post if you ride roads that cars and trucks drive on your fine with 10/12 psi. Now if you ride Moto trails that is too much psi. When we riding got your bikes ready.😁