Airing down for gravel / dirt?

[elkroeger]

Hi guys,

 

I don't have any background riding in dirt or gravel (except for the occasional patch of road construction). I understand that lots of folks deflate their tires for softer surfaces.

 

Is there a simple rule of thumb as to what pressures to use (for instance, deep loose gravel might be 50%, hard gravel might be 75%, etc.)? What would be the lower pressure limit? And is it safe to assume that deflating my tires would be useful with the street tires that I have on my RS?

 

Mostly I'm just interested. I don't have any big ideas about RS-ing up to Deadhorse.... At least not yet.

 

thanks!

[Roadwolf]

I participated in the Rawhyde One Day Clinic last year and Shawn Thomas said that they run anywhere from 22-24 psi for offroad stuff... and when they occasionally hit pavement, they don't bother airing up the tires if they are not going to be on the pavement for any length of time (he said the only harm is wearing out the tires sooner). Hope that helps.

 

 

[dirtrider]

Evening Bruce

 

That is a tough question to answer.

 

The basic answer is IT DEPENDS!

 

On type of tires, types of rims, weight of bike with rider & gear, type of bike, type of terrain, speed ridden, ambient temps, how far you are riding at what speeds on what type of ground (like sand, rocks, logs, etc)

 

Without rim locks, knobby tires, & good brakes with some motor horsepower you probably don't want to go much below 13-14 psi. Especially if you have inner tubes in them (good chance you will spin a rim in the tire & rip a tube valve stem off).

 

With rim locks you can go down a bit lower on soft sand.

 

If you are riding a heavy street bike with street tires & aluminum rims you can't go very low on rocky ground or hard pack roads or you risk bending a rim buy hitting a pot hole or rock.

 

If you are riding an RS with street tires I wouldn’t think you would want to go much below 22-24 psi & if the road is hard with large sharp edged pot holes probably not that low.

 

My suggestion is to go with as much tire pressure as you can ride with (within tire specs) as it is easier to let some out if you find deep sand or loose gravel than it is to add more along the way if it turns out to be rocky or full of hard pack with pot holes.

 

[tallman]

"If you are riding a heavy street bike with street tires & aluminum rims you can't go very low on rocky ground or hard pack roads or you risk bending a rim buy hitting a pot hole or rock.

 

If you are riding an RS with street tires I wouldn’t think you would want to go much below 22-24 psi & if the road is hard with large sharp edged pot holes probably not that low."

 

What he said.

 

No fun when the rim fracks.

[Rocer]

Evening Bruce

 

That is a tough question to answer.

 

The basic answer is IT DEPENDS!

 

....

 

 

I never ride the KLX without em.

[elkroeger]

Hmmm... Interesting. thanks! Those are higher suggestions than I would have guessed. I might try it sometime and see how it goes.

[lkraus]

Hmmm... Interesting. thanks! Those are higher suggestions than I would have guessed. I might try it sometime and see how it goes.

 

Carry a pump when you do...

[outpost22]

If you are running alloy wheels, you are at risk in flat spotting them airing down too much.

On my "tubed" F650GS with spokes, I run 18 front 20 rear on dirt/gravel. Having run the RT down some questionable roads (2 up ) I won't go below 38 psi. You just shouldn't be going THAT fast that you have to air down those tires with alloys (unless you own a rim company).