Mountain Biking - Help!! how much air pressure on wheels

I have a Giant XTC2 2003. The tires seem like it needs some air.

How much lbs air pressure do i need to put on it.

30-40 PSI

Depends on the tire and the terrain.

On a 2.1, rough terrain, I usually run 45psi... on the road, or singletrack that's packed down, I'll run 50.

On a 1.85, I usually have 40-45... I get more pinch-flats that way, but I find with the smaller tire, I need the lower pressure to make a good sized contact patch.

Those are for XC... if you're DH'ing, and have a 2.3 or higher, you can get away with 20-30psi easy. Really depends on the tire size, and where your riding.

Joe

Since by the bike I will assume xc riding I would go to 45 to 60psi. Dh or extreme uphills I go as low as 25psi.

Originally posted by johndoe
I have a Giant XTC2 2003. The tires seem like it needs some air.

How much lbs air pressure do i need to put on it.

As stated, it's all about what type of riding you are doing, what type of rider you are and what type of tire you are running. I would suggest that you experiment. Change the psi a couple of pounds @ a time, and you'll learn what works best for you.

PS: I ride XC, and generally go with 38-40 in the front and 40-42 in the back. Good luck!

20psi = pinch flat city on a XC tube setup if you ride hard.

Somebody correct me if I am wrong but doesn't depend on the weight of the rider as well?

If someone is riding with 20psi and a 200lb rider got on it would already be flat.

Of course. Depends on rider weight, tire, terrain, and tube to an extent.

But any XC tire/tube setup with any size rider is asking for trouble much below 30psi. Gotta go tubeless if you wanna go that low :) But then you're gonna bend a wheel if you ride like me :D

Palooka. I ride at 25psi at times and hae never had any problems. I definately don't ride tubeless. :)...

Weight does matter and each situation warrants something different. At 250, air in tires is pretty different from someone in the 150 weight range.

johndoe

Assuming your tires are correctly sized for your rims (OEM's are pushing the envelope now days with thinner and thinner rims). Please stay within the range printed on the side of the tire sidewall (i.e. 40-60psi). Always remember that you are ultimately riding on this "air" cushion, it protects your rims from $$ damage. Be certain to check the pressure on a regular periodic basis! Once a week isn't too often.

Ask a bicycle mechanic "what is the leading cause of bicycle repairs" and you will likely receive the reply. “Owner negligence of adequate tire pressure!” No other single factor is so often ignored and it’s a shame since it’s something that all but the youngest children can easily do.

Note: One of my favorite bicycle tools is my floor pump (with built in gauge). When I obtain it my quality of life increased immensely!

When was the last time your checked your tire pressure?

Cheers;

Mael, you must ride like a girl scout? :confused:

Its hard to ride like a girl scout in whistler. Even the easy single tracks are tough :)...I only ride with that psi going dh because I have no rear suspension it helps. I usually ride between 35 and 40 in the rear for most situations. Any higher and I gain speed but loose traction on the single tracks. I made sure to spend a lot of money on a rim and get a very tough sidewall tire that is wide. No problems (I don't do urban so I may run into problems in that specific situation)

Trials riders ride with 20psi and less in some situations.

Ultra-wide tires add a bit of tube protection just because there is more rubber.

But I've pinch flatted on the road at 25psi on 2.0 tires.

With my UST setup, I can run my 2.3" Conti Verts at 20psi all day and not have problems. My 2.0" Mosquitos feel like they are going to roll off the rim at 20psi.

I was kidding about the girl scout thing by the way. lol

Originally posted by palooka
Ultra-wide tires add a bit of tube protection just because there is more rubber.


I should have clarified in the first place :D



But I've pinch flatted on the road at 25psi on 2.0 tires.


I would never think to run that low on what are essentially wider xc tired. When that narrow I pump up higher so I can go really really fast (says in a kids voice)

I have rokko240's which are around 2.5 and they are heavy and have very thick side walls. I wouldn't try with a thinner wall or narrower tire.



I was kidding about the girl scout thing by the way. lol

Hence the reason I put a smiley in my response. ;)

I'm 165 lb., ride and race XC.

1.95" Kenda Kharisma Lite tires and Mavic 517 rims.

36 psi front. 40 psi rear. Pinch flatted once (rear) this season on a rocky downhill.

On dirt roads I'll pump up to 50 psi to reduce rolling resistance.

45-50 with xc, 30-35 with DH/Freeriding.