Avon Storm 2 Ultra

[pembsgtr]

Update.
just back from an 100 mile trip and these tyres are very confidence inspiring, feels like far more grip than the oem BT021. Did a circuit that has lots of twisties and regularly ride it and found corners were taken a bit quicker than when shod with the Bridgstones.
Hvae also had the tyres inflated with nitrogen, to 42psi front and rear, TPS reads 49psi and after an hours riding had not moved either way up or down so it looks like the nitrogen does not expand as air inflated tyres does. All in all v pleased with the only need a bit of rain now to see what the wet weather grip is like.

[Lonewolf]

Why would the TPS read 7 psi more than what you actually put in, are they that unreliable?

[pembsgtr]

Looks like they are not very good under nitrogen, have checked pressures myself after ride out and they still bang on 42 Psi. Will use tps as an indicator of pressure loss in future

[Lonewolf]

I'm gonna look into this. I'd never even heard of it before you posted it.

[pembsgtr]

Formula one teams use nitrogen, rally teams and MOTO GP, also I believe aircraft tyres too, due to extremes of temperature they go through. Fella in work does a bit of amateur rallying and reckons that a tyre inflated with nitrogen can be hammered from cold whereas a tyre inflated with air has to be underinflated to start and cannot be used fully until they up to correct operating temperature. It's all very advanced I know but there must be something in it. Ats offer tyre inflation now apparently. When in having bike tyres done this morning, the local undertaker was in having his limo tyres replaced, and said he'd had his hearse tyres inflated with nitrogen and was now getting 8 miles to the gallon more, I guess you can read into it what you will but, I'm going to give it a go for one set of tyres at least to see how they do

[Boomer]

Well, you can use 70% Nitrogen or 100% Nitrogen.
70% is more commonly called AIR.

Pure Dry (no moisture) Nitrogen gives better predictability in a tyre.
It is normally used in racing as they need predictability.

It is the the water vapour in the air that causes the 2 PSI rise in pressure between cold and warm tyres.
I use this as a gauge of when the tyres are warm enough.

It will make no difference to a road user if they use 70% or 100%.
Nope, no MPG gains, no handling changes, no tyre wear improvements.
Checking your tyre pressures more often will have more of an effect.

As for the 42psi-49psi difference, one of your gauges is off, and by a fair amount.
The TPS should show the same pressure for air and pure Nitrogen.

[Rusty]

Sounds like Mr Boom knows what he's talking about !

[pembsgtr]

Pressure checked today with a third pressure gauge a "race x professional" and it reads 42 psi and tps still reading 7psi higher, guess I'd better take the bike back to get tps changed under warranty if tps is that inaccurate.
Surely though if a tyre pressure changes during use it is going to change shape and therefore wear differently thanvif itvis subject to a constant and designed pressure, I'm no tyre expert but that's my thoughts and I'm willing to give the theory a try at least, it may even be a placebo thing , who knows

[Kwikasfuki]

The TPS on my 08 tends to be +1 PSI out

[routemaster]

Pressure checked today with a third pressure gauge a "race x professional" and it reads 42 psi and tps still reading 7psi higher, guess I'd better take the bike back to get tps changed under warranty if tps is that inaccurate.

I am assuming that ordinary pressure gauges we use on a daily basis are basically a mechanical measurement of pressure, although it may have a digital display but I don't know how the TPS measures pressure but I am guessing it is an electronic or electro/mechanical measurement rather than mechanical.

If the TPS measures pressure electronically or by electro/mechanical means does the use of nitrogen affect it's calibration/measurement?

I don't know if anybody here knows the answer or not but one quick way of finding out is re-inflating a tyre of with air and see if the TPS is still out.

It would also be an interesting one to see if Kawasaki agree to replace the TPS, as the basic assumption will be that the tyres and the TPS are designed to work with air rather than Nitrogen.

Kind regards

Steven

[pembsgtr]

They wouldn't be able to tell that the tyres had been inflated with nitrogen though  :P

[Boomer]

Our TPS use electronic direct pressure sensors, but so do most modern LCD pressure gauges.
Since it's measuring pressure which is gas independant it shouldn't make any difference.
Nitrogen is chemically pretty neutral too so I can't see it reacting with the sensor in any way, not that change from 70% to 100% would affect it.
If the TPS is off by that much then it's a warranty replacement, if you can be bothered.

[pembsgtr]

Have today been in contact with kawasaki UK with regards to nitrogen use in tyres and they see no Issues,  have also today connected an optimate flying lead to bike, whether the fact I have disconnected battery and connected has had any effect the tps is now reading pretty much same pressure as pressure gauge, so I think I'll leave well alone for now

[Martin#30]

I would have thought that the sensors also measure air temperature, and thus adjust the pressure reading based on that temperature. My logic is that my tyre pressure sensors read the same (+/- 1psi) after 100 yards as they do after 50 hard miles. The air pressure *must* have increased with temperature, so I guess the TPS adjusts for a relative constant reading.

Perhaps the temp/pressure relationship for nitrogen is different, hence the variety?

Martin.

[Boomer]

This morning when cold, my display showed 43PSI.
This was about 100yds from home once the display woke up.
10 minutes/6miles later at about 70Mph it was showing 45PSI.
That is about all the change you will see on your TPS.
The pressure increase for a temperature change of +5C to +50C is not that much and will usually result in the +2PSI I see.

However, if you use Dry Nitrogen then you will most probably see very little change as the increase with temperature is mostly down to condenstation in the tyre turning to water vapour and expanding when it gets hot, so with Dry Nitrogen you are only dealing with the Ideal Gas Law and not with several Gas Laws (one each for N2, O2, CO2, H20).

The TPS do measure temperature but they only compensate for the Nitrogen Ideal Gas Law, not for Water.