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Questions about Tire Pressure For Gravel

5.5K views 13 replies 9 participants last post by  TravellingStrom  
#1 ·
I've read a lot on this site about people reducing their tire pressures when riding in gravel. It seems that the most common practice is to reduce the pressure to about 20 PSI. I'm kind of curious about this. I've ridden in quite a bit of gravel and have never reduced my tire pressures, but I've often thought about it. I'm curious to know the theory behind reducing the pressures. I assume it is to create a larger contact patch and increase stability. I carry a compressor and guage, so changing pressures isn't a problem, but before I start doing it I'd like to know more about the reasoning behind it.

Can anyone shed some light on this for me?

Thanks.

SS
 
#2 ·
When I am riding by myself, I drop the front tire to 20psi and the rear to 25psi. When the wife is with me, I drop the front to 25psi and the rear to 30psi.

It makes a huge different.

But, purchase a little compressor or appropriate hand pump so you can lift the psi back up for pavement and higher speed riding.....otherwise the bike tends to be squirrely with low psi.
 
#3 ·
If you are just riding on a decent gravel road I would not change a thing, just ride it. If you are going on a poorly maintained surface you can drop the pressure. After I bent a rim I will not be reducing the pressure below 25 psi on either tire.
 
#4 ·
A bent rim sucks.

I was wondering about that. I was thinking it would only be necessary to reduce the pressure on very loose and deep gravel. Hard packed gravel is very stable and an adjustment isn't required.

Anyone else reduce pressure? Why?



SS
 
#5 ·
I guess it depends on your perspective, I've experimented with tire pressure

I don't air down for gravel or any surface, but I do air down for cold about 4 psi

the pressures that peeps are talking about make me feel like I'm riding on a flat tire, nope, not for me is that why why seem to go slow, when ever I am leading a ride off the beaten path, seems like I am always waiting



 
#7 · (Edited)
Best thing is to experiment with it yourself. It's good if you develop the skills to not have to air down... but I can tell you it will give you better traction and cushion the ride considerably.

Until you go over the same stretch with different pressures, you're not going to really notice any difference (just like when you are tuning a suspension)

Once you get a feel for what changes with the lower pressure, you can decide for yourself if or when you air down. Consider it just another tool in your bag of tricks.

Keep in mind, gravel or not, if you intend to run at high speed the tires will heat up faster at the lower pressure. Also as mentioned, rims are more susceptible to damage at high speeds.
 
#8 ·
I drop mine to 23F/26R when going on dirt. I find when the tyre is too hard, when I hit rocks the tyre skips and jumps off them, when the tyre is softer, it tends to roll over the rocks and rides a straighter line, it makes me feel personally more secure, which lets me be softer on the handle bars.

Try both, see how it handles, also learn to stand up, more control that way

Cheers
TS
 
#9 ·
When you guys air down I'm assuming the pressures you're stating are hot pressures right?

Usually I have a lenghty ride to the gravel and have to air down there requiring hot pressure checks.

I normally run my tires pretty hard for street use and if I'm going to be on any lenghty dirt sections I'll air down some just to lessen the ride harshness.
 
#10 ·
My pressures were meant to be cold. I have to drive to the fun, typically arrive in the evening and camp or stay at friends. In the morning before I head out I could drop the pressure. Again, if it is just gravel roads I leave the pressure alone, I only reduce the pressure if it' going to be loose sand or off roadish.
 
#11 ·
A question on reinflating the tires.

After dropping the pressure for a gravel ride, when you get back to tarmac, should you reinflate to:
normal cold pressure or
higher than normal pressure or
lower than normal pressure?

What should you do, since the tire is hot and the new air going in is cold?
I don't want to waste an hour waiting for the tire to cool down.