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JZ
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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?
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4x4abc
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"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
Harald Pietschmann
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David K
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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].
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JZ
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| 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]
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4x4abc
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you are right - physics don't apply to Chevy/GMC
Harald Pietschmann
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mtgoat666
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Poppyc0ck!
[Edited on 10-13-2018 by mtgoat666]
Woke!
“...ask not what your country can do for you – ask what you can do for your country.” “My fellow citizens of the world: ask not what America
will do for you, but what together we can do for the freedom of man.”
Prefered gender pronoun: the royal we
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JZ
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The point of that post, you missed it my friend.
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bajatrailrider
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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.
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JZ
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| 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.
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PaulW
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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.
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PaulW
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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.
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mtgoat666
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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 
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 
[Edited on 10-13-2018 by mtgoat666]
Woke!
“...ask not what your country can do for you – ask what you can do for your country.” “My fellow citizens of the world: ask not what America
will do for you, but what together we can do for the freedom of man.”
Prefered gender pronoun: the royal we
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PaulW
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Goat, Good job finding load tables
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bajatrailrider
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| 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.
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bajatrailrider
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| 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.
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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.😁
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