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Well, for you guys wondering about a gauge....

they don't make one for presta valves that I have ever found, but they do make an adapter that you can screw on the presta so that you can use a schrader type gauge. They are quite cheap and usually available at any good bike shop. Otherwise if the idea of pulling the cap and putting an adapter on every time you want to check pressure seems like a PITA, which it can be, a good floor pump with an accurate gauge is the easiest option. Those are about the only options for pressure reading with presta valves.

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Pressure isn't relative at all...

Unless you list the tire volume.

A gauge for presta can be found on most floor pumps made in the past two years.

I ride 35 psi on 2.4 tires.

Ken
 

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High pressure here

rdickens48 said:
I was just wondering what you guys run for tire pressure?
Am I the only one that rides with high pressure in their tires. I run 50 PSI in my Cinder 2.25s. My twisted logic for this would be 1) less chance for pinch flats, 2) less chance for rim damage when hitting hard obstacles such as rocks, 3) let my suspension compensate for the higher pressure.

If someone wants to help me to understand what I might be missing by not lowering the pressure, I'm all ears.

Bob
 

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Tire Pressure

I have a Presta gauge that I have had for several years originally bought for my road bike. Presta has been around for a very long time, so I don't know why the trouble with a guage. Here is one I found in about 20 seconds. I am saying it is any good, but... http://www.jensonusa.com/store/product/PU703B00-Topeak+Smarthead+Digital+Psi+Gauge.aspx
I have not used in it a while since I bought a pump with it on it.

Okay, as far as pressures go, at my usual mostly non-technical (but with some jagged rocks) ride, I run 38 in the rear and 35 in the front. If I go to many other more technical areas, I bump these by 4 pounds. This is on Panaracer Fire XC Pro 2.1 both. Cold weather slightly less. I have found that going by feel leaves me making adjustments often on the trail or repairing tires. I know now if something does not feel right, it is me or something other than my tire pressure. So now, I check mine before every single ride.

As far why running as low a pressure as you can get away with? Simple, traction! When I run higher then what I do the back and front of the bike slip off of rocks and makes the bike less enjoyable to control. I think most if not all will agree with this. Not to mention that it is very bouncy to ride with rock hard tires.

I am 250 lbs.

Ken.
 

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Traction....

Call_me_Clyde said:
Am I the only one that rides with high pressure in their tires. I run 50 PSI in my Cinder 2.25s. My twisted logic for this would be 1) less chance for pinch flats, 2) less chance for rim damage when hitting hard obstacles such as rocks, 3) let my suspension compensate for the higher pressure.

If someone wants to help me to understand what I might be missing by not lowering the pressure, I'm all ears.

Bob
Lower pressure (within reason) will provide better traction than higher pressure. Think cornering. With higher pressure, your tire's tread will break loose sooner than the side wall. With lower pressure, your tire's sidewall will give more before your tread does. You'll be less likely to slide out in the corners.

The same principal applies to riding over rocks, logs, etc.
 

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Pinch Flats

azdrawdy said:
Been running 48 psi in my IRC Mythos XC 2.1 for several years now. I don't like pinch flats and really don't like the squirrely feeling I get when the psi drops below 40 psi.

Michael
Now see, that's the difference, I really love pinch flats. :)

For some reason I run just a few pounds higher than the 100 lb lighter riders I ride with. I got two flats this year and neither were pinch flats. I have been told that for a tubbo, I am light on my bike.

I really hate the squirrely feeling too, and every time I get a different set of tires, I need to find that sweet spot. My rear rim is also wider (521D) and seems to give my tire a little more stability.

Ken.
 

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Thanks Ken

Ken in KC said:
Lower pressure (within reason) will provide better traction than higher pressure. Think cornering. With higher pressure, your tire's tread will break loose sooner than the side wall. With lower pressure, your tire's sidewall will give more before your tread does. You'll be less likely to slide out in the corners.

The same principal applies to riding over rocks, logs, etc.
I knew there might be an issue with washout on cornering, but I guess it's not much of an issue cus I'm such a slowpoke. :D I never did equate lower pressure to better traction over obstacles. I'll have to lower the pressure and experiment a bit.
 

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Call_me_Clyde said:
I knew there might be an issue with washout on cornering, but I guess it's not much of an issue cus I'm such a slowpoke. :D I never did equate lower pressure to better traction over obstacles. I'll have to lower the pressure and experiment a bit.
One of the biggest differences in traction with lower pressure is in wet and muddy conditions. If you are running tubes, you shouldn't go much below about 38 PSI in the rear and a pound or so less in front. If you go much lower than that, you will be risking pinch flats. If you want to enjoy an insanely great ride, go tubeless and drop down to 28-30 PSI. Then you'll really know what traction is.
 

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Discussion Starter · #16 ·
Thanks guys, I am new to the presta valve, so I didn't know you had to unscrew the little nut that keeps the valve closed. So I thought I might need a special guage for the presta valve, but I got my regular guage to work.
I was wondering about the tire pressure, because on my rides this past weekend, my hardtail felt to hard. I was thinking that maybe a lower tire pressure would help to soften the ride, but I didn't know how low was too low and would cause problems. Thanks for the feedback, I will experiment this weekend.
 

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Whatever

BrandonJ said:
One of the biggest differences in traction with lower pressure is in wet and muddy conditions. If you are running tubes, you shouldn't go much below about 38 PSI in the rear and a pound or so less in front. If you go much lower than that, you will be risking pinch flats. If you want to enjoy an insanely great ride, go tubeless and drop down to 28-30 PSI. Then you'll really know what traction is.
There are too many generalities in your statement to even begin to respond. I run below 38 psi on both my tires. I haven't pinch flatted in about 3 years. All of this without the "benefit" of tubeless tires.

Lower pressure = better traction, regardless of conditions.
 

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Cool Ken!!! I didn't know they made a guage....

ken50397 said:
I have a Presta gauge that I have had for several years originally bought for my road bike. Presta has been around for a very long time, so I don't know why the trouble with a guage. Here is one I found in about 20 seconds. I am saying it is any good, but... http://www.jensonusa.com/store/product/PU703B00-Topeak+Smarthead+Digital+Psi+Gauge.aspx
I have not used in it a while since I bought a pump with it on it.
Ken.
for presta valves specifically. Of course I guess I've never really looked for one. One does not look for what one doesn't need. I've always had a floor pump with a gauge and never really needed anything else. I've used the adaptors for years if I only needed to just check tire pressure. But 99% of the time when I need a guage it's because I'm adding air anyway. I probably won't ever get a presta guage, just don't need it, but it's good to know that they are out there! You learn something new every day. Thanks.

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Tire pressure is one of the most subjective decisions out there. Total preference call within a reasonable operating range.

I ride 29ers exclusively and I'm limited to basically a 2.0 tire. At 260# I typically run low to mid thirties in the front and upper 30s in the rear.

Running Yes Tubes I've avoided pinch flats for several years.
 
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