XPost: comp.os.linux.misc   
   From: robin_listas@es.invalid   
      
   On 2025-12-10 06:22, c186282 wrote:   
   > On 12/9/25 21:20, Carlos E.R. wrote:   
   >> On 2025-12-09 20:11, The Natural Philosopher wrote:   
   >>> On 09/12/2025 14:50, Carlos E.R. wrote:   
   >>>> On 2025-12-09 15:09, The Natural Philosopher wrote:   
   >>>>> On 09/12/2025 11:57, Daniel70 wrote:   
   >>>>>> On 9/12/2025 9:08 pm, The Natural Philosopher wrote:   
   >>>>>>> On 08/12/2025 22:39, rbowman wrote:   
   >>>>>>>> On Tue, 9 Dec 2025 00:20:38 +1100, Daniel70 wrote:   
   >>>>>>>>   
   >>>>>>>>> I usually put it down to my Tyres being under-inflated, so   
   >>>>>>>>> their diameter is less so it takes more revolutions of the tyre to   
   >>>>>>>>> cover a specified distance.   
   >>>>>>>>   
   >>>>>>>> I don't think under inflation would change the diameter enough to   
   >>>>>>>> throw the speed off that much. In my case the diameter of the 14"   
   >>>>>>>> wheels is noticeably less than the 15". I see that in the spring   
   >>>>>>>> when I'm going back to the 15". If I jack the car up enough so the   
   >>>>>>>> 14" leaves the ground and I can remove it sometimes I have to jack   
   >>>>>>>> a little more to get the 15" on.   
   >>>>>>>>   
   >>>>>>> There is no such thing as diameter on a tyre. It isn't circular.   
   >>>>>>> Might as well ask yourself 'what is the diameter of a tank track'   
   >>>>>>>   
   >>>>>>> What counts is circumference and the tyre is elastic enough to   
   >>>>>>> expand   
   >>>>>>> a little under high pressure.   
   >>>>>>   
   >>>>>> .... and that pressure would get higher due to usage heating the   
   >>>>>> tyre.   
   >>>>>>   
   >>>>>>> And to wear a little lower.   
   >>>>>>   
   >>>>>> ... which would reduce the tyres diameter, so decreasing the   
   >>>>>> Ground speed.   
   >>>>>   
   >>>>> THE TYRE HAS NO DIAMETER., It is not circular.   
   >>>>   
   >>>> It doesn't matter. We can calculate it.   
   >>>>   
   >>> No you cannot.   
   >>   
   >> Yes, we can. It is a formula with π in it.   
   >>   
   >>> Any more than you can calculate the 'diameter' of a tank tread.   
   >>> You might choose to evaluate (circumference over pi), but that is   
   >>> just a number that has no meaning in this context. There is no   
   >>> physical dimension that corresponds to it   
   >>   
   >> Irrelevant.   
   >>   
   >> We measure the actual distance travelled for a number of turns. From   
   >> that we calculate the effective circumference, and from that, the   
   >> effective radius.   
   >>   
   >> None of those have to be the apparent length seen by a measuring tape   
   >> on the wheel.   
   >   
   >    Planning to lock the steering and send it 500km   
   >    towards Kyiv ???   
      
   :-D   
      
   >   
   >    If not, then the estimation based on raw diameter   
   >    or circumference will be Good Enough to guess if   
   >    yer new tires put you at legal risk.   
   >   
   >    It's just TOO easy to get hung up on the decimal points.   
      
   Here we can not just put any wheel on a car, it has to be an approved one.   
      
   --   
   Cheers, Carlos.   
   ES🇪🇸, EU🇪🇺;   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)