Nitrogen in tyres.

[shooey]

I had my tyres filled with nitrogen to day 

It was free, and though I used the factory pressures 42 rear/36 front. I ride with a pillion.

I found that the front felt over inflated and have dropped it down to 32, and the rear to 40.

Feel the same now as it ususally does.

Not sure of the benefits other than my tyres wont go down as quick 

Any body else use it in their bike, or is it a gimmick 

[Gaz]

I think the benefits are something to do with more consistent pressures and the lack of moisture helps prevent corrosion (dried air would have the same benefits) - essential in Suzukis So it is better than normal air but I don't think I'd pay extra for it

[shooey]

Yep he did say it would be about £5.00 to refill them, and fooked if I'd pay that for air 

And the only rust I have on my bike, except for the small peice on the lip of my tank, is a rusty renthal pillion bar 

So there 

[Biff]

I have always used nitrogen in my tyres

I seem to get better miles-per-tyre, and they don't seem to deflate so quickly. Although I still check them regularly

[Alan@asperformance]

being lighter than air helps you corner faster i find.......................

[Biff]

being lighter than air helps you corner faster i find.......................

.................and it is possible to get to the edge of a 190 section tyre too !!

[arryace]

nitrogen shmitrogen......isnt air 70 % nitrogen. If its free then y not wudnt pay 4 it! Apparently black bikes are fastest

[Gaz]

nitrogen shmitrogen......isnt air 70 % nitrogen. If its free then y not wudnt pay 4 it! Apparently black bikes are fastest

78%

[rotax81]

its used for constant pressures and was banned in my kart series 

[arryace]

78%

ah close 

wouldn't the tyre also have air in it at atmospheric pressure (around 14psi i think) even when fully deflated.

[rotax81]

ah close 

wouldn't the tyre also have air in it at atmospheric pressure (around 14psi i think) even when fully deflated.

at 14psi mine dont feel deflated 

[bambi]

Nitrogen molecules are larger than say oxygen. They are less likely to escape through the rubber (or whatever the tyres are made of) and the seal to the rim. They also expand less when heat is applied i.e warm tyres. If you run nitrogen your cold pressures will be a little higher than with 'pure' air.

[Kermittheflyingbog]

Nitrogen molecules are larger than say oxygen. They are less likely to escape through the rubber (or whatever the tyres are made of) and the seal to the rim. They also expand less when heat is applied i.e warm tyres. If you run nitrogen your cold pressures will be a little higher than with 'pure' air.

OK oxygen molecules are smaller than nitrogen, but the size of both is so minute that the molecular density of tyre rubber would not discriminate between the two in such away to let oxygen out at a faster rate than nitrogen, also as previously stated 78% of the compressed air you normally blow your tyres up with is already nitrogen so therefore the effect of oxygen escaping would only be from the remainder of the 22% of air (actually out 90% of that 22%) so that can't be the reason.
My understanding is that the second part of your quote is most probs the reason, using a single gas and specific gas mix (as in f1) is to get a more constant and consistant tyre pressure less effected by changes in temperature of both the internal and external area of the tyre 

[scooby]

we had a big thread about this a few yrs back,cant remember what thew outcome was though


tony (r1nos) is the man i would think to explain the main reason for it's use,although i think the constant pressure was a big factor 

[Gaz]

Nitrogen molecules are larger than say oxygen. They are less likely to escape through the rubber (or whatever the tyres are made of) and the seal to the rim.

I wouldn't have thought so, Nitrogen is element 7 and Oxygen is 8 and both tend to occur in molecules of 2 atoms. Also not sure that molecule size will have much affect on the efficiency of a mechanical (i.e. rubber) seal.

{edit} Beaten to it by Kerm