Sunday, April 29, 2007 - 08:32 am, by: Mike Bradberry(Halflife)
If I fit wider tyres, does that mean I need higher pressures than say the standard? The reason I ask this is that the centre on the tyre in a wider section is not supported as much as say a standard tyre, therefore if it has higher pressure the centre can be supported more.
Sunday, April 29, 2007 - 09:19 am, by: David Vaughan(Davidv)
Pressure is pressure. You are supported principally by the air, not the sidewall, and air pressure is uniform within the container so the centre is supported. However, if you have wider tyres you probably have lower profile tyres. This brings the rims closer to the ground and more at risk of road impact on potholes and the like. This can destroy the tyre as well as (though less likely) damage the rim. Keep your pressure toward the upper end of your preferred range on lower profile tyres, or raise your preferred range. There is still no single ideal pressure whatever your profile.
Sunday, April 29, 2007 - 09:39 am, by: Mike Bradberry(Halflife)
I feel I am not being clear. If you could imagine a tyre of say 10 inches wide without any air, fitted on an appropriate rim, it would be easy to push the centre but on a narrower tyre, say 5 inches, the required pressure to push it in the centre would be less, hence my question.
Sunday, April 29, 2007 - 11:22 am, by: David Vaughan(Davidv)
I feel I was clear but not well understood .
Your example is immaterial to a tyre with normal air pressure. Sidewall strength becomes insignificant compared with the uniform air pressure and the radial belt stiffness. It is, however, important to maintain stiff pressures on tyres with a low sidewall height i.e. those with a lower profile on larger wheels. You no longer use the tyre as a significant springing medium,
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