Optimizing suspension for washboard?

[comptiger5000]

I'd tend to suggest an initial air down that's not super aggressive. Maybe drop 10 psi (15 or so if you're running a lot of pressure normally), see how it feels, check the tire temps. If it feels good and temps are good, run with it. If it's still riding rough and tire temps are good, drop a bit more pressure and see what happens.

Even within a given weight range / normal pressure range, different tires will react differently to airing down (due to different sidewall stiffness, etc.) so 2 almost identical rigs (same weight, same size tires but different tire models) may need somewhat different pressures when aired down.

 

[BigSwede]

Yeah, lotta variables here, some experimentation is in order.

 

[SoCal Tom]

i'd pay money to watch someone run washboard with less than 20 psi.

I usually run about 12, when I had my bronco on 35s I would go lower on the 15 inch rims. The record in our camp was when my Dad got my 69 CJ5 stuck in a dune, and kept airing down the 31s ( bias ply) and when he got back to camp there were about 4 lbs in the tires.

 

[hemifoot]

a bronco on 35's with 15"rims isn't the same as a 3500 on 35's with 20's .way too many variables depending on trucks/tire/wheel combo's .i couldn't run 20 psi, especially with my camper on and towing my boat.i would be dead in a ditch with trashed rims,and i always run e range.my ridge grapplers are f rating and i still wouldn't trust them at that psi.

 

[LandCruiserPhil]

a bronco on 35's with 15"rims isn't the same as a 3500 on 35's with 20's .way too many variables depending on trucks/tire/wheel combo's .i couldn't run 20 psi, especially with my camper on and towing my boat.i would be dead in a ditch with trashed rims,and i always run e range.my ridge grapplers are f rating and i still wouldn't trust them at that psi.

I cant see a reason for airing down towing a boat but 20psi might be as bad as you think. Hard to see in the pictures our CTD 3500 6sp on 35's on 17" Hummer rims at 20psi running the beach in Mexico without issue.

 

[comptiger5000]

Don't forget this: the slower you're moving, the more you can air down safely. At low speeds you don't have to worry about tire heat much if at all, just mechanical factors (tire squish, rim strikes, de-beading, etc.) that limit how much you can air down. At speed, heat becomes a much bigger problem and too much heat will cause a tire to shred itself.

If you're doing 50 mph down miles and miles of washboard road, you can't air down nearly as far as you can crawling through a trail or moving slowly on the beach. In the 50 mph case, you might only be able to go a few psi below what the load / inflation charts specify for your weight before heat becomes a concern (which may already be lower than street pressure in some cases, as the pressure where the tires feel / wear / behave best on the street is sometimes a bit higher than the pressure required to safely carry the load).

 

[LandCruiserPhil]

Don't forget this: the slower you're moving, the more you can air down safely. At low speeds you don't have to worry about tire heat much if at all, just mechanical factors (tire squish, rim strikes, de-beading, etc.) that limit how much you can air down. At speed, heat becomes a much bigger problem and too much heat will cause a tire to shred itself.

If you're doing 50 mph down miles and miles of washboard road, you can't air down nearly as far as you can crawling through a trail or moving slowly on the beach. In the 50 mph case, you might only be able to go a few psi below what the load / inflation charts specify for your weight before heat becomes a concern (which may already be lower than street pressure in some cases, as the pressure where the tires feel / wear / behave best on the street is sometimes a bit higher than the pressure required to safely carry the load).

Most aftermarket TPMS display temperature along with pressure

 

[hemifoot]

do most aftermarket tpms light up like a christmas tree like stock ones do if you run under the set low pressure like my ram? i got so tired of it i removed them from all 3 of my sets of tires.i don't like carrying my camper without them,but i have no choice.my winter set went all wonky if it got too cold and my offroad set is usually under 40 psi anyway.

 

[rruff]

do most aftermarket tpms light up like a christmas tree like stock ones do if you run under the set low pressure like my ram?

For $60-90 you can get a set with continuous readout, with alarms wherever you want them. Solar powered display (set on the dash), pressure sensors are built into the caps (no need to install in the rims).

 

[IdaSHO]

Most of the aftermarket units are pretty adjustable for high and low warnings.

This style that Ive looked at can be set as low as 16PSI

While Id have trouble trusting a valve stem cap sending unit, I will say Ive been temped to try them out...

 

[LandCruiserPhil]

Most of the aftermarket units are pretty adjustable for high and low warnings.

This style that Ive looked at can be set as low as 16PSI

While Id have trouble trusting a valve stem cap sending unit, I will say Ive been temped to try them out...

Off road I like the cap style because traditional valve stem style are rigid and can break with contact.

 

[IdaSHO]

Not all stem TPMS sensors are rigid.

The TPMS sensors/stems on my 2011 super duty, for example, are rubber/non-rigid.

Rigid ones seem to be on the way out. I'm seeing less and less every day it seems.

 

[LandCruiserPhil]

Not all stem TPMS sensors are rigid.

The TPMS sensors/stems on my 2011 super duty, for example, are rubber/non-rigid.

Rigid ones seem to be on the way out. I'm seeing less and less every day it seems.

Good to hear now to see if they will fit/work on a Toyota:sombrero:

 

[cody4359]

There are four things that impact performance on washboard:

Tire "spring rate" - eg, airing down is better
Suspension Spring Rate - Most lift kits are way too stiff IMO
Shock Valving - Lots of opportunity for improvement here, will expand on this
Suspension Geometry - steep angles can transmit harshness

When it comes to shock valving there are a lot of trade offs. Super soft shocks ride great on washboard but will bottom out too easily. We can optimize washboard performance with some of our new valving techniques while retaining decent bottoming control. But someone concerned with mixed terrain that includes long stretches of washboard are still best suited to an adjustable shock.

A slightly related note is that washboard absolutely kills shocks due to the extremely fast movement and heat build up. Most expo rigs probably need 2.5's if they're going to hit washboard at moderate speeds.

for a jeep comanche about 4k lbs that does pnw logging roads with potholes and washboards, some normal trail riding, and hwy driving on a 4.5" coils, what spring and shock combo do you reccomend without breaking the bank but having a decent setup. I'm running bilstein 5125s on rough county coils. just swapped out mt RE coils and noticed a improved ride but I'd like to make it a little plusher on the sharp bumps

Sent from my SM-G900V using Tapatalk

 

[SoCal Tom]

for a jeep comanche about 4k lbs that does pnw logging roads with potholes and washboards, some normal trail riding, and hwy driving on a 4.5" coils, what spring and shock combo do you reccomend without breaking the bank but having a decent setup. I'm running bilstein 5125s on rough county coils. just swapped out mt RE coils and noticed a improved ride but I'd like to make it a little plusher on the sharp bumps

Sent from my SM-G900V using Tapatalk

My favorite setup on my Early Bronco was Bilstien 7100 shocks with "pre-runner" springs. It weighed in around 5K, and it rarely bottomed out with that setup, it ate up washboard stuff, and as long as I kept the wheels on the ground it wouldn't bottom out, even then it was pretty tolerant of my mistakes. If you can fit those shocks you will love them.
Tom