Mountain Biking - wat psi?

wat psi should i put my mtb @? i hear its like 50 but isn't the too much?

i wud sa n e were between 35 and 50

Sorry, just wanted to point out that typing in "AOL'ese" makes it harder for us to read and therefore, harder to help you. Taking an extra second to spell words out helps everyone.

35-50 psi is typically a good range. It depends mostly on the type of riding. If you ride mostly roads, run it closer to 50 psi. If you're riding in soft or sandy dirt, you'll want the lower pressures to give you better traction.

It depends on how much you weigh, and what type of riding you do.

I like a hard ride so I put 50psi in the rear and 60psi in the front using 26x2.0 tyres. I figure the front tyre can have more air as the suspension takes out the harshness. I ride mainly on fire tracks which aren't that bumpy. The type of terrain can be the deciding factor. But it's also personal preference.


CHEERS.

Mark

i wud sa n e were between 35 and 50

Sorry, just wanted to point out that typing in "AOL'ese" makes it harder for us to read and therefore, harder to help you. Taking an extra second to spell words out helps everyone.
Kid should be happy you got to him first. I'm in a mood to chew on an AOL'er tonight

In my mountain bike, I have around 50 PSI, and use it for jumping, freeride, light dh etc, most things really
Trials bike anything between about 15 and 30 PSI, depending on terrain/moves etc
BMX about 80 or 90
Road bikes 110
For my other bikes, and generally at work, I pump tyres up to around 40 (depending on the particular bike and pressure guidelines on the tyre sidewall)
50 PSI sounds about right to be honest, but check your tyre first.

It depends on what tires you are running and what terrain you are riding. Tubes or tubeless?

On mine I generally run between 36 - 40 in the front and 38 - 42 in the rear. This is with continental explorer / escape tires using Stan's no tubes. This is for rocky, rooty singletrack where traction is very important.

i ride both dirt but mainly road w/ fat tires. i put it at like 40. good?

usually it says on the side wall the ideal psi

Kid should be happy you got to him first. I'm in a mood to chew on an AOL'er tonight

I saw the clouds gathering and felt it was my duty to do a good deed. ;)

I saw the clouds gathering and felt it was my duty to do a good deed. ;)
Go tell your Scoutmaster you earned a Merit Badge. :beer:

i ride both dirt but mainly road w/ fat tires. i put it at like 40. good?

40 psi sounds pretty low if you are not running tubeless. You are just asking for a pinch flat. If you are riding the road then you should go with a lot higher pressure to lower the rolling resistance.

usually it says on the side wall the ideal psi


Uh....no - it usually gives you the acceptable range of pressure (ie. 35PSI - 60PSI.)

40 psi sounds pretty low if you are not running tubeless. You are just asking for a pinch flat. If you are riding the road then you should go with a lot higher pressure to lower the rolling resistance.

i do both 50/5.0 40 is low?

I run 38 on my XC bike and singlespeed, 32 on my freeride bike. Low pressure = better ride. Unless you are using really small tires, or a lot heavier than my 155lbs, I wouldn't worry about pinch flats. I have NEVER had one.

40 for dirt and road? Sounds low to me. If your using knobbies on road i would look at the 60's. If you wnat the most efficient machine use slicks for road :).

To each their own, and terrain and tire choice has everything to do with it. But my impression is many I ride with pump their tires up too high.

On my 26" bike (2.4" Mutanoraptor/2.1" Traction Pro) I ride 30 psi front and 40 psi rear.

On my 29" bike (2.1" Nanoraptors) I ride 28 psi front and 38 psi rear.

FWIW, I weight 200 pounds.

This is a nice balance where I don't get killed on rocks but can maintain traction up most climbs.

It's important not to go too low or you'll be in danger of snake bites and bent rims.

An easy way to adjust it to start with 45 or 50 psi, but leave your valve caps of and your stems open. Every mile or so reach down a release a quick pfffttt of air. Pay attention to how the rear hooks up on climbs, and how the front tracks on the downhills. You'll know when you go to low because the bike will feel squishy and have some side-to-side "flex". Plug a tire guage in and read what pressures you ended up at. Continue to play with your pressures in small increments. Higher for tacky and smooth rolling trails. Lower for loose, steep and dry.

Confused yet? :lol:

If im goingg offroad i like it around 40-45 for the rear and 35-40 for the front. BUt if its at all wet im looking at 40 at the max for the rear and front usually at low 30's

i do both 50/5.0 40 is low?

If riding the bike on the road then yup, forty psi is very low for that. As for on the trails if you are running 40 psi with tubes then you are increasing the risk of snake bites. Of course all tires and trails are different so it is always a judgement call.

WOW!!! must feel like ya'll are riding on steel tires. ;)

In sandy conditions I run between 18 and 22 psi, hard packed, and rocks I run 25 to 30 depending how big the drops are (2.5 NBX tires). As for snake bites, I have had 3 in 10yrs of riding/racing and I use tubes and I weigh in at 265lbs.

What it comes down to is how the bike feels to you. I would suggest trying different psi and decide which feels wright for your style/type of riding. Higher psi will give you less rolling resistance but less traction, lower psi will give better traction but higher rolling resistance.

:beer:

WOW!!! must feel like ya'll are riding on steel tires. ;)

Nope, tires feel great with low rolling resistance. I generally run 38 - 42 pounds in standard Continental Escape and Explorer tires with Stan's no tubes. Tires feel great, great traction and very fast. Corner great as well. Keep in mind this is for xc racing not downhill. Around here people running less than 30 psi with tubes flat constantly. I've had the privilidge of watching plenty of people change tubes. WV isn't exactly equipment friendly. :)

Okay, I put it at 50, both tires.

Keep in mind this is for xc racing not downhill. Around here people running less than 30 psi with tubes flat constantly. I've had the privilidge of watching plenty of people change tubes. WV isn't exactly equipment friendly.

I realize that but even when I used to race xc I never had a need for more then 38psi. Just don't like how the bike feels. As for equipment friendly trails, I/we stay away from those 'cause they are not as fun :D and a lot of riders pinch flat as well.

:beer:

40 psi sounds pretty low if you are not running tubeless. You are just asking for a pinch flat. If you are riding the road then you should go with a lot higher pressure to lower the rolling resistance.

I only run 25 psi in the front tire of my Kona and 35 psi in the rear tire. But then I use DH tubes and tires that are 2ply.

Welp as you can see air pressure is just like everything else in this sport, everyone has different preferences. :)

I like a hard ride so I put 50psi in the rear and 60psi in the front using 26x2.0 tyres. I figure the front tyre can have more air as the suspension takes out the harshness. I ride mainly on fire tracks which aren't that bumpy. The type of terrain can be the deciding factor. But it's also personal preference.


CHEERS.

Mark

Traction and deformation ...

The amount of pressure in the tire should be proportional to the load you place on it. On most mountain bikes, the rear wheel bears most of the load.

The reason is you want a tire that is slightly deformed (bulging). This forces the tread that's normally on the side down onto the ground. It actually ends up "grabbing" the ground.

Front wheel traction is critical on the front wheel since that's where you do your steering. An underinflated tire won't bite and can lead to poor steering performance.

For the poster:
I suggest that you air up the tires to about 40psi each (If you're over 200#, 50 psi each, 250 60 psi each). Than hop on and check to see if the tires a giving a bit under your weight. You may have a friend help you. If they're too "hard" let some air out of them (this procedure is easier than adding air). Repeat, find something that seems to work for pavement.

For the next step, you'll need a pump you can take with you on the trails. This isn't an extra expense, you should have one with you anyway (along with a patch kit or spare tube). Find a small to moderate trail section you can ride over and over. Ride it twice. If your bike seems to be breaking loose, let some air out.

Remember that "optimum" inflation will vary for rider, condition, tire and tube. So it's pretty much up to you to hunt and peck and find your "sweet spot".

40 psi sounds pretty low if you are not running tubeless. You are just asking for a pinch flat. If you are riding the road then you should go with a lot higher pressure to lower the rolling resistance.

First 40psi is very common among riders. Second, you have no idea what his weight is. If he weighed 90lbs, 40psi would probably be too much pressure.

I ride 65/50. Think that's too much air ???? I weigh 280lbs.

As far as the "sidewall" pressure goes. You can only rely on the minimum. The "maximum" pressure isn't set by engineers, it's set by lawyers. I've pumped fires up to 80psi with no problem (save excessive loss of traction ;-) ).

First 40psi is very common among riders. Second, you have no idea what his weight is. If he weighed 90lbs, 40psi would probably be too much pressure.

You're right, I don't know everything and I have to problem admitting it. I was giving my opinion which is what this board is for. I was trying to help a guy out. Opinions vary and mine is no better or worse than anyone else's. I post from my experience and the experience of others that I have ridden with. I know what works on the trails where I ride and what doesn't. I have spent enough time on a bike that I feel confident that when I give my opinion it is pretty reliable. I don't post just to post.

"The amount of pressure in the tire should be proportional to the load you place on it"

I put 110 PSI in my road bike's tyres, but I put (much) more load onto my trials bike wheels, which are at a much lower pressure.

"The amount of pressure in the tire should be proportional to the load you place on it"

I put 110 PSI in my road bike's tyres, but I put (much) more load onto my trials bike wheels, which are at a much lower pressure.
http://img203.exs.cx/img203/91/arrowtoreplywquote6it.jpg

You're right, I don't know everything and I have to problem admitting it. I was giving my opinion which is what this board is for. I was trying to help a guy out. Opinions vary and mine is no better or worse than anyone else's. I post from my experience and the experience of others that I have ridden with. I know what works on the trails where I ride and what doesn't. I have spent enough time on a bike that I feel confident that when I give my opinion it is pretty reliable. I don't post just to post.

I don't know everything. And I show it by asking people the things I do not know.

I don't think you were expressing an opinion. I think you were expressing a preference. Your "experience" given conditions may be completely worthless to someone who has different starting constraints (like their weight). That preference is even less valuable when you fail to mention what your constraints are.

I didn't mean to criticize. I only meant to point out that perhaps you should try to understand a problem before solving by simply stating a solution to your problem that may or may not be similar.