Tyre pressure chart including ambient temperature

[Kwikasfuki]

Tyre pressure can be down to personal preferences or keeping at the recommended manufacturer settings. Either way, the TPS should not be used as the de facto readout. Only use the TPS for guidance.

To correctly set the tyre pressure you will require four items:

1. A digital tyre pressure sensor. Cost: £5 - £10
2. A infra-red temperature thermometer. Cost £20 - £50
3. A portable tyre inflater. Don't do the measurements and then ride to your local filling station as the tyres will have warmed up by then. Cost £25 - £50 (don't be tempted to buy the ones on offer at £3.99 - they are useless). Some inflators come with a digital tyre pressure sensor. The one I purchased was woefully out with its reading hence the purchase of a dedicated one.
4. A chart showing the variance in PSI based on ambient temperature (see below). Cost: Free   ;D

Point the thermometer at each tyre and record the temperature. Then refer to the chart below and inflate the tyre to the correct PSI.

Temperature (c)                   PSI

          -15                              36
          -9                                37
          -4                                38
          +2                               39
          +7                               40
          +13                              41
          +18                              42
          +24                              43
          +30                              44
          +35                              45
          +40                              46
          +46                              47

Going by the above chart the TPS variance is ~ +1 PSI

[da_boom]

Are people that anal about tyre pressure? Or am I missing something fundamental?

[Kwikasfuki]

It can extend the life of your tyre as well as ensuring the tyre pressure won't be the cause of any nasty accident. Low pressure = quicker squaring off the tyres and damage to the side walls.

I tend to check tyre pressures once a week. Takes five mins. Should be part of any routine maintenance.

[Lonewolf]

I must admit I am a bit anal when it comes to tyre pressures.  ;D I check my tyre pressures religiously, (is that goood or bad)  :-\
I've had a bad experience in the past with a car which had the wrong tyre pressures because somebody had without my knowledge put different tyres and wheels on one of my cars. We are only talking a difference of about 5psi but at the speeds I was driving, (legally) it was having a very negative impact on the steering and handling. I would not want to experience the same thing on a bike :o

[Rusty]

Chaps Chaps Chaps ... come on... tyre pressures are really VIP stuff. I check mine every week, it only takes a moment. Its' not anal just a bit of common sense. A few pounds out will alter the entire characteristics of the bike. Remember the manafacturers spend heaps of money on research and development and they will tell you that the tyre will operate best at a certain Psi... you get the best ride, the best wear, the best control, not more or less but at that pressure. if you have an RTA, even if it's not your fault, and your bike is examined by the Police or an AIU officer and the tyre pressures are out an Insurance company will use that against you to get out of paying .. they will simply say that, for example " you would have stopped in time if your tyres were correctly inflated " or " I put it to you Mr Bloggs that you lost control of the bike on the bend because your tyres were incorrectly inflated and my client was injured as a result of your negligence " etc etc .. get the idea ? They don't have to prove it but it's just a weakness in your case if your bike isnt' maintained .... take care out there !

[Kwikasfuki]

I find 42/42 works best for me and although I agree that tyre pressures are very subjective, I believe there is a tolerance range based on the bike, the riding style and the tyre.

The GTR is a heavy bike and needs a good set of tyres maintained properly. As the only contact point between the road and myself is the tyres I'm going to buy the best ones available and maintain them correctly. Also don't forget the bike can output a lot of torque at the rear wheel which needs to have the grip.

When reading tyre reviews be wary of where the tyres are being tested. You will normally find they are in a hot climate where a poor tyre will provide good grip. Hence why I believe the PR2s aren't good for a UK cold climate although they are brilliant in the summer.

[2kwacks]

since getting my gtr1400 2010 model, have used the built tyre sensors each time have been out, they seem to work ok. however I like to check my tyre pressure before I ride, the tyre pressure sensors dont register this untill you have started riding. which kind of defeats the object, now call me lazy! but if the prseeure is low, you then need to find a garage with a air line, thats if your lucky enough to find one that works. anyway! I have allways used those tyre pressure valve caps, you know the ones I mean! they have 3 colours, red,green,yellow. simples! if its green your good to go, if its yellow you have lost approx 5 p.s.i just use your 12v compressor, of course if its red. then your not going anywhere in a hurry, got theses littles gems on my zzr1400 and they work excellently all the time. so bought 2 of the same 42 p.s.i ones for the gtr1400, and quess what! they will not register any pressure. I can only asume there is somethink in the tyre valve that prevents the p.s.i valve cap from working! now I thought the principle of the tyre valve is for letting air in and letting air out. so why wont theses bloody things work!! ;)

[Lonewolf]

I cant answer that question, only thing I can think of is that the original tyre pressure sensors built into the Kawasaki valve are not designed to then be capped with another tyre sensor. I know thats a lame excuse, but thats the best I could come up with at this time of the day. I'm not convinced it'll get any better later either.  :D

But, yes like you I like to know my tyre pressures are spot on. Its amazing how much difference the handling is affected by what might be considered a very minimal loss of pressure from a tyre, especially at higher speeds.

[Kwikasfuki]

I honestly suggest that everyone carries one of these on their bikes. The valve stem is rigid and does not flex at all. So if you need to top up in an emergency there is a strong chance the air pressure connector at the petrol station won't fit. Happened to me. Fortunately I had some canisters that inflated the tyre to 20psi which was enough to limp me home.

[Lonewolf]

Yes I have one of those which lives in my pannier bags, just in case.  ;D

[2kwacks]

I honestly suggest that everyone carries one of these on their bikes. The valve stem is rigid and does not flex at all. So if you need to top up in an emergency there is a strong chance the air pressure connector at the petrol station won't fit. Happened to me. Fortunately I had some canisters that inflated the tyre to 20psi which was enough to limp me home.

yes I to, invested in one of theses. it now lives in my clove box, not used it yet thou! acording to the built in tyre sensors the pressures are all ways correct. average between 42 p.s.i and 46 p.s.i which I suppose is correct due to the tyre reaching higher temps when running!

[maximus]

Different tyres have different pressure recommendations. Generally 42/42 works fine but some tyres are better with lower temps. All depends on your riding style

[Nygie]

Hi people, first post new to the board an all.
Straight into the technical stuff :)

I think the point that should be made regarding to tyre pressures and temperature (for those who don't already know)
is that the warming process of riding increases the pressure so if you are at -6 and you adjust the pressures to 42, then when the tyre warms due to friction the pressure will increase a fair amount giving a higher pressure therefore affecting the handling of the tyre.
Something to do with the long deceased Robert Boyle I believe. i'm sure theres a neat little equation somewhere but I'm too tyred ;) to look.
God I hope this place is a little more lively than 1400gtr.org.uk, I recognized a few of the same names over here :)
Later

[Ziderman]

I think if you consider weight of Rider , climate , Pillion , luggage....your going to be forever trying to work out optimum tyre pressure...so in my opinion ( & Im always right ;D) a PSi one or two either way is not going to make a huge difference.

Nige...you say about lively forum...it's a little slow, I go back to the FJR one , great crack on there still. They dont give toss weather still got an FJR or not.
Guess it takes time to get together a big bunch or GTR owners & the FJRs been around lot longer than the GTR...

Did get banned for a story I told though....but it was true story though.

[ChrisB]

My dad always taught me to check tyres, levels and lights every week. I always have done and have taught my son and daughter to do the same. Doing the basics can prevent future expense and problems. I tried to get the wife to check hers and she told me it was my job along with washing and filling her car. So I check at least 10 tyres a week now. Well she does all the ironing so I cant complain. My dad also said, you spend most of your life in bed or in a pair of shoes, so buy the best you can afford of both. LOL.