[Boezack]

After a cold 50 degree ride today I figured I'd check my tire pressure just to see where I was at. I decided to wait till they got good and cold so I waited and came back to check. When I did much to my surprise I was down to 28 pounds of air in both tires. I just had speedy in to get the TORS tune and the tech and I talked about tire pressure, and I think he said he adjusted the pressure, but not to 28. I may switch to Nitrogen so I don't have to worry about losing air so fast.

Anyone out there running with Nitrogen in their tires on the street? Just wondering.

 

[Prestimp]

Old myth or not I am not sure, but somehow I have had it in my head that 10deg = 1psi, So as long as your watching tire pressures with moderate weather changes you should be fine.

Whoever is the local engineer please feel free to flame away at my inaccurate statements :-D

 

[Avi8or]

Fill 'em with helium and make the bike lighter.
Seriously can't get the stuff on the street here.
IMHO not worth the hassle or expense.
You might have a small leak or possibly a bent rim.
We fill fill our plane tires with it though.

[ This message was edited by: Avi8or on 2006-12-11 05:36 ]

 

[dr_gallup]

Absolutely no good reason to use N2 for bike or cars tires but if you want to feel free. Your pressure drop is probably primarily due to temperature but they should not be set the same!

I never trust the local mechanics to know how to correctly set tire pressure or oil level. Sad but true.

 

[9264]

Never heard a good argument yet for running Nitrogen in road tyres. Unless you happen to sell the stuff.

 

[Curmudgeon]

There's a good chance your mechanic's guage reads higher than yours, too. Of course, that wouldn't explain why the pressure is the same in both tires, but it would explain why you're getting low readings.

 

[R100Pilot]

As long as we're talking exotic gasses, how about filling your tires with hydrogen. Then do a burnout.

And be sure to send video :lgh:

 

[FINAO]

Cold temperatures contract, Molecules slow down,
Heat expands. Molecules speed up.

Basic physics of the gaseous phase.

 

[Boezack]

I kind of work in the service business and have had Nitrogen put in my car tires once. It didn't cost anything and makes no difference in a passenger car tire, with the exception that you don't lose air/pressure so fast in cold weather. Some cars dealers put in cars to get people to come back for service.

I'm going to put more air in before I go out next time. I've read a few threads on tire pressure and some say no one should ever be on the street with 28, especially in the 40 to 50 degree weather.

 

[Guest]

So what is the tire pressure benchmark front/back? :???:

 

[TonUp]

On the Street I run 32F/34R
On the track I run 30F/29R

You can run a little higher and get your tires to last a little longer, I want them to stick a lot more so I run lower air pressure on a stickier compound tire.

So Far I have run

Pilot Powers (did not like them)
Pirelli Corsa (Sticky)
Dunlop Sportmax GP Front and 208 GP rear (Super Sticky Track, and very agressive street riding)
Next spring I have a new set of Corsa III to try.

Ton Up!

 

[rs_tt]

I`ve got nitrogen in my bike tires I`ll never do it again .It makes you lazy you end not checking the tire pressure often enough,and i like changing the pressure up or down depending on the type of riding i`ll be doing that day.

 

[TonUp]

Get an accurate gauge, and check air pressure every ride or at least weekly.



Ton Up!

 

[DavePreston]

I also was surprised at how much air pressure my Speed Triple lost in a fairly short time.

I have been spoiled because my previous Triumph, a Sprint ST, had nitrogen in the tires. The advertised benefits are that nitrogen molecules are 4 times as large, and therefore leak much more slowly. In addition, for track day nuts, nitrogen does not change pressure nearly as much when the tires are hot. The cost is pretty minimal (if I recall we charge $13 for both tires) so it is worth a test. I have been meaning to have this done, and checking the pressures last week moved it higher up my "to do" list.

 

[dr_gallup]

On 2006-12-12 13:38, DavePreston wrote:
The advertised benefits are that nitrogen molecules are 4 times as large, and therefore leak much more slowly. In addition, for track day nuts, nitrogen does not change pressure nearly as much when the tires are hot. The cost is pretty minimal (if I recall we charge $13 for both tires) so it is worth a test.

1. Air is 78% nitrogen, N2, and 21% oxygen, O2. So even if you put air in the tire, it's already 78% nitrogen. Many of the so called nitrogen generators don't produce much more than 90% nitrogen.

2. At relatively low pressures (ie tire pressures) N2, O2 and water vapor will all behave as ideal gases, and follow PV=nRT. Pressure will increase or decrease to the same extent as the temperature increases or decreases regardless of which gas is in the tire. (Even at 300 psi, which is about 20 atm, there is little deviation from ideality.) Therefore the comments about N2 not changing in pressure as the temperature changes are without merit.

3. The rate of effusion (or diffusion) of a gas through a porous membrane depends on the molar mass and to some degree on the molecular diameter. N2 and O2 are almost the same size and N2 is lighter than O2 (28 g/mol vs 32 g/mol) so if either gas were to effuse out of the tire, nitrogen would do it more quickly. Luckily, tires are designed not to be porous membranes.

4. N2 and O2 both have essentially the same specific heat capacity, about 1.0 J/gK, and thermal conductivity, about 0.00026 W/cmK. Water vapor has a specific heat capacity of about 2 J/gK. But remember, water vapor will constitute less than 1% of the air in the tire. So the idea that N2 has different heat handling properties is also without merit.

 

[Limey]

yeah, what the DR said.

 

[9264]

As I said, never heard a good argument yet for running Nitrogen in road tyres. Unless you happen to sell the stuff.

 

[scgstuff]

DR,

I looked at your sig line and saw the patents. I am assuming these are yours since the user name and the patent registrant are the same name. Does Triumph pay for the use of these in the S3? Just curious how that works....

Shawn

 

[dr_gallup]

On 2006-12-12 15:08, scgstuff wrote:
DR,

I looked at your sig line and saw the patents. I am assuming these are yours since the user name and the patent registrant are the same name. Does Triumph pay for the use of these in the S3? Just curious how that works....

Shawn

The companies I used to work for own the patents, I got a dollar for each one. Triumph uses Keihin injectors & ECUs in the 1050, SAGEM injectors & ECUs are still being made in France and were last fitted to the '06 955 Daytona and Tiger.

 

[TheGuvnor]

On 2006-12-11 21:03, TonUp wrote:
On the Street I run 32F/34R
On the track I run 30F/29R

You can run a little higher and get your tires to last a little longer, I want them to stick a lot more so I run lower air pressure on a stickier compound tire.

So Far I have run

Pilot Powers (did not like them)
Pirelli Corsa (Sticky)
Dunlop Sportmax GP Front and 208 GP rear (Super Sticky Track, and very agressive street riding)
Next spring I have a new set of Corsa III to try.

Ton Up!

Anyone here tried the Dunlop D616s yet....oops maybe I should do a search before I get flamed.... :hammer: