Best/Worst OEM Wheels
Discussion
Tigger2050 said:
If you take a completely differently constructed tyre then the patch might be different. A solid rubber tyre would be different.
We are talking road cars here and different sizes of very similarly made tyres. Tyre manufacturers may use slightly different rubber compounds, will have different tread patterns but they are very similar in construction. Put 15" Michelens against 20" Michelen's on the same car and the contact patch will be the same. The difference between Michelen, Pirelli or Bridgestone's will be absolutely minimal.
I don't know why people are so upset about the basic physics that control the contact patch on pneumatic tyres.
Perhaps they don't like to accept that their 'garden roller' tyres are putting no more rubber down than the basic model's tyres.
Yes, the GCSE physics interpretation is clear that the contact patch is determined by the tyre pressure and weight. But there are other factors. One is that the construction of the tyre will provide some constant to the supporting ability of the tyre, in effect removing an element of the vehicles weight from the equation.We are talking road cars here and different sizes of very similarly made tyres. Tyre manufacturers may use slightly different rubber compounds, will have different tread patterns but they are very similar in construction. Put 15" Michelens against 20" Michelen's on the same car and the contact patch will be the same. The difference between Michelen, Pirelli or Bridgestone's will be absolutely minimal.
I don't know why people are so upset about the basic physics that control the contact patch on pneumatic tyres.
Perhaps they don't like to accept that their 'garden roller' tyres are putting no more rubber down than the basic model's tyres.
But surely to achieve a large contact patch on a skinny tyre, the deformation would be significant - certainly more than if the tyre was wide. This would mean the construction would be different to allow for this, it would make it much less responsive to direction changes and would generate massive heat at high speeds.
So I think the implication that wide tyres have no benefit beyond "fashion" just isn't true.
RedSwede said:
Yes, the GCSE physics interpretation is clear that the contact patch is determined by the tyre pressure and weight. But there are other factors. One is that the construction of the tyre will provide some constant to the supporting ability of the tyre, in effect removing an element of the vehicles weight from the equation.
But surely to achieve a large contact patch on a skinny tyre, the deformation would be significant - certainly more than if the tyre was wide. This would mean the construction would be different to allow for this, it would make it much less responsive to direction changes and would generate massive heat at high speeds.
So I think the implication that wide tyres have no benefit beyond "fashion" just isn't true.
Again, the relationship holds for similarly constructed tyres. If you have tyres with completely different sidewall constructions then the contact patch on a particular car would vary. Most road car tyres are similarly constructed. You get the run flats and they may have a different size of contact patch. However, different sizes of the similarly constructed run flat would have the same contact patch at the same tyre pressure. Want to increase your contact patch, lower your tyre pressures or load the car up, changing tyre size won't do it.But surely to achieve a large contact patch on a skinny tyre, the deformation would be significant - certainly more than if the tyre was wide. This would mean the construction would be different to allow for this, it would make it much less responsive to direction changes and would generate massive heat at high speeds.
So I think the implication that wide tyres have no benefit beyond "fashion" just isn't true.
Most people put the same or similar make of tyres on their cars and the 15" Bridgestone's will be putting down the same contact patch as the 20" Bridgestone's.
Also on a smooth surfaced track or road the wider, lower profile, tyre will hang on longer in corners due to the different shape of the contact patch and lower slip angle, so there is an advantage in those conditions, not many roads like that in the UK though.
Here is a scholarly study on car tyres.
https://www.researchgate.net/publication/314718704...
The conclusion is............. "In case of the tested tyres the decrease of tyre height and the increase of its width and diameter is some kind of compromise described by almost constant contact area which depends only on unit load of tyre and pressure inside the tyre."
RedSwede said:
Tigger2050 said:
If you take a completely differently constructed tyre then the patch might be different. A solid rubber tyre would be different.
We are talking road cars here and different sizes of very similarly made tyres. Tyre manufacturers may use slightly different rubber compounds, will have different tread patterns but they are very similar in construction. Put 15" Michelens against 20" Michelen's on the same car and the contact patch will be the same. The difference between Michelen, Pirelli or Bridgestone's will be absolutely minimal.
I don't know why people are so upset about the basic physics that control the contact patch on pneumatic tyres.
Perhaps they don't like to accept that their 'garden roller' tyres are putting no more rubber down than the basic model's tyres.
Yes, the GCSE physics interpretation is clear that the contact patch is determined by the tyre pressure and weight. But there are other factors. One is that the construction of the tyre will provide some constant to the supporting ability of the tyre, in effect removing an element of the vehicles weight from the equation.We are talking road cars here and different sizes of very similarly made tyres. Tyre manufacturers may use slightly different rubber compounds, will have different tread patterns but they are very similar in construction. Put 15" Michelens against 20" Michelen's on the same car and the contact patch will be the same. The difference between Michelen, Pirelli or Bridgestone's will be absolutely minimal.
I don't know why people are so upset about the basic physics that control the contact patch on pneumatic tyres.
Perhaps they don't like to accept that their 'garden roller' tyres are putting no more rubber down than the basic model's tyres.
But surely to achieve a large contact patch on a skinny tyre, the deformation would be significant - certainly more than if the tyre was wide. This would mean the construction would be different to allow for this, it would make it much less responsive to direction changes and would generate massive heat at high speeds.
So I think the implication that wide tyres have no benefit beyond "fashion" just isn't true.
Edited by thiscocks on Tuesday 19th March 13:22
Edited by thiscocks on Tuesday 19th March 13:22
alorotom said:
How dare you ... that’s blasphemy ... I’m waiting for the 3spoke resurgence and I’m confident it WILL happen!
3 spokes are generally awful. But I do think that they work on old school Saabs. I am biased - witness my 900 T16. It just wouldn't look right with anything else!
Untitled by baconrashers, on FlickrHarry Flashman said:
alorotom said:
How dare you ... that’s blasphemy ... I’m waiting for the 3spoke resurgence and I’m confident it WILL happen!
3 spokes are generally awful. But I do think that they work on old school Saabs. I am biased - witness my 900 T16. It just wouldn't look right with anything else!Untitled by baconrashers, on FlickrHarry Flashman said:
alorotom said:
How dare you ... that’s blasphemy ... I’m waiting for the 3spoke resurgence and I’m confident it WILL happen!
3 spokes are generally awful. But I do think that they work on old school Saabs. I am biased - witness my 900 T16. It just wouldn't look right with anything else!Untitled by baconrashers, on Flickr98elise said:
Harry Flashman said:
alorotom said:
How dare you ... that’s blasphemy ... I’m waiting for the 3spoke resurgence and I’m confident it WILL happen!
3 spokes are generally awful. But I do think that they work on old school Saabs. I am biased - witness my 900 T16. It just wouldn't look right with anything else!Untitled by baconrashers, on Flickr
2172cc said:
98elise said:
Harry Flashman said:
alorotom said:
How dare you ... that’s blasphemy ... I’m waiting for the 3spoke resurgence and I’m confident it WILL happen!
3 spokes are generally awful. But I do think that they work on old school Saabs. I am biased - witness my 900 T16. It just wouldn't look right with anything else!Untitled by baconrashers, on Flickr
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