Bring back ride quality!!
Discussion
PumpkinSteve said:
Do you think going from 195/45/R16 to 165/75/R14, giving a tyre sidewall height increase of 26mm, would make any significant difference in ride quality?
Yes, partly because the sidewalls are higher - any compliance in the sidewall essentially makes the wheels sprung rather than unsprung mass over small bumps - the higher the sidewalls, the larger the bumps that it effectively isolates the weight of the wheels from. But also, the wheels are smaller and so will be lighter, and the tyres are narrower so will probably also be lighter. I wouldn't be surprised if that combination knocked 5kg off each corner's unsprung mass.
I don't know what you drive, but you can't fit 14 inch wheels to a lot of modern cars because the brakes are too big.
kambites said:
Yes, partly because the sidewalls are higher - any compliance in the sidewall essentially makes the wheels sprung rather than unsprung mass over small bumps - the higher the sidewalls, the larger the bumps that it effectively isolates the weight of the wheels from.
But also, the wheels are smaller and so will be lighter, and the tyres are narrower so will probably also be lighter. I wouldn't be surprised if that combination knocked 5kg off each corner's unsprung mass.
I don't know what you drive, but you can't fit 14 inch wheels to a lot of modern cars because the brakes are too big.
Thank you. It's only a Fiesta, Ford offer alloys 14"-16" as standard anyhow. The spec I got only came with 16-inchers though.But also, the wheels are smaller and so will be lighter, and the tyres are narrower so will probably also be lighter. I wouldn't be surprised if that combination knocked 5kg off each corner's unsprung mass.
I don't know what you drive, but you can't fit 14 inch wheels to a lot of modern cars because the brakes are too big.
PumpkinSteve said:
Thank you. It's only a Fiesta, Ford offer alloys 14"-16" as standard anyhow. The spec I got only came with 16-inchers though.
Bear in mind that you'll have a fair bit less grip because firstly you have less tyre width and secondly you'll probably be limited to much less performance orientated tyres.Having said that, tyres will probably be cheaper, so you'll be able to get better ones for your money. "Michelin Energy Savers" are pretty good and are probably available in that size.
kambites said:
Bear in mind that you'll have a fair bit less grip because firstly you have less tyre width and secondly you'll probably be limited to much less performance orientated tyres.
I've never driven a car back-to-back with different size/width tyres fitted. It would be interesting.Guvernator said:
Dracoro said:
Guvernator said:
But why should it be up to us to "fix" ride quality issues by fitting different wheels or suspension?
Well, because "you" (not literally you of course), when buying the cars news strayed away from buying the model with 16 inch wheels in "SE" spec and opted for the 19 inch wheels with low profile (or worse still, runflats) tyres and "sport" suspension. In other words, "you" broke it in the first place 
Regardless, if most people chose the SE/16 inch wheels etc. then this wouldn't be an issue (other than for those that "have" to have them - there are other cars to choose from BTW).
Anyway, my point is no-one is "forced" to put up with crap riding cars, they can just buy the better riding ones but many choose not to. Of course, it doesn't help that manufacturers/dealers "encourage" people to option up their cars to make more money but they don't force them to.
This then filters onto the used market where there are few good riding cars because so many of the new car buyers ticked these options...... Tyres/wheels can, to an extent, be easily changed, suspension less so.
MC Bodge said:
kambites said:
Bear in mind that you'll have a fair bit less grip because firstly you have less tyre width and secondly you'll probably be limited to much less performance orientated tyres.
I've never driven a car back-to-back with different size/width tyres fitted. It would be interesting.Dracoro said:
Anyway, my point is no-one is "forced" to put up with crap riding cars, they can just buy the better riding ones but many choose not to. Of course, it doesn't help that manufacturers/dealers "encourage" people to option up their cars to make more money but they don't force them to.
Many buyers choose the car/image they want and spec up the car to suit. The large wheels (and sports suspension to a certain extent), being a cost option, are probably seen as 'better' or just more desirable because they are more expensive and provide a visual indication that the car is not just 'bog-standard'(although how many other people would really notice?). Wheels then get bigger with each generation.
The 'ride' that is delivered with the car is incidental. I'm not sure how many people test drive car types before they buy them.
Edited by MC Bodge on Friday 17th February 11:06
kambites said:
Guvernator said:
I think my next option is to try non-runflats with a slightly bigger profile. Does anyone have any recommendations on a tyre manufacturer which gives good ride quality? I've looked on the web but tyres don't seem to ever be rated on ride quality, only on grip, tread life and wet weather handling, all of which are mostly irrelevant on a decent modern tyre to be honest. 
In my experience anything will be vastly better than the run-flats you have on there now. Generally speaking softer side-walls give a better ride but make the steering less sharp and destroy some of the steering feel (no idea I'f you'd notice that on something as numb as a 3-series, but it's bloody obvious in the Elise). I know Toyo T1-R are very soft, but I don't know about other brands. The model of tyre seems to make a much bigger difference to the road noise than the ride quality, if that matters.
I may try to find out if I can fit slightly bigger profile tyres without effecting things too badly.
entropy said:
Does a couple of inches in rim size make a difference on the track? I know this is subjective but it does annoy me when reading Evo they go on how a car looks great with big wheels.
Lower profile tyres give a significant improvement in steering feel and turn-in sharpness and the size itself has little disadvantage on track, because they tend to be smooth. However, most big wheels tend to be heavy which is bad. FWIW went from this:
to this:
Improvements were. More comliant ride, less road noise and improved steering feel. By virtue that they're also narrower all round, the car moves about more under you, understeers less and is far more enjoyable. Now all these differences aren't huge, but they're there and they're noticable. They're also what come on the car as standard...
It's still too hard IMO, but better than it was on the bigger wheels with rubber band tyres.
Blame the cheapo camera for making it look orange in the second pic.
to this:
Improvements were. More comliant ride, less road noise and improved steering feel. By virtue that they're also narrower all round, the car moves about more under you, understeers less and is far more enjoyable. Now all these differences aren't huge, but they're there and they're noticable. They're also what come on the car as standard...
It's still too hard IMO, but better than it was on the bigger wheels with rubber band tyres.
Blame the cheapo camera for making it look orange in the second pic.
Edited by juansolo on Saturday 18th February 08:01
PumpkinSteve said:
Do you think going from 195/45/R16 to 165/75/R14, giving a tyre sidewall height increase of 26mm, would make any significant difference in ride quality?
Google TRC Tyre Calculator. Will give you rolling radius change /speedo error and subjective comfort rating for any wheel / tyre profile change.Jaguar steve said:
Google TRC Tyre Calculator. Will give you rolling radius change /speedo error and subjective comfort rating for any wheel / tyre profile change.
I know, I've already checked out all of that info, I just didn't know how much of a difference in comfort it would make. I don't know if the Fiesta is inherently hard riding and the large wheels are just a smaller part of the overall issue, it could just be the way it's sprung/ damped for all I know. I have now changed down from 195/45/R16 to 195/50/R15 and it still produces an almighty bang over bumps, although it probably is a little better, I just don't know if it's worth the expense of changing down a size again.
PumpkinSteve said:
I know, I've already checked out all of that info, I just didn't know how much of a difference in comfort it would make. I don't know if the Fiesta is inherently hard riding and the large wheels are just a smaller part of the overall issue, it could just be the way it's sprung/ damped for all I know. I have now changed down from 195/45/R16 to 195/50/R15 and it still produces an almighty bang over bumps, although it probably is a little better, I just don't know if it's worth the expense of changing down a size again.
Going up to a 60 or 65 will definitely see an improvement in "squishyness" if that's what you're after. As a bonus the tyres will be much cheaper.entropy said:
Does a couple of inches in rim size make a difference on the track? I know this is subjective but it does annoy me when reading Evo they go on how a car looks great with big wheels.
The other reason for big wheels is the ability to run big brakes. Rubber band tyres aren't necessarily the be-all and end-all for racing though - look at F1.Dr Jekyll said:
kambites said:
Bear in mind that you'll have a fair bit less grip because firstly you have less tyre width
Surely (all other things being equal) grip is a function of contact patch size. Why would a narrow tyre give less grip than a wide one with the same tyre pressures?juansolo said:
FWIW went from this:
to this:
Improvements were. More compliant ride, less road noise and improved steering feel. By virtue that they're also narrower all round, the car moves about more under you, understeers less and is far more enjoyable. Now all these differences aren't huge, but they're there and they're noticeable. They're also what come on the car as standard...
It's still too hard IMO, but better than it was on the bigger wheels with rubber band tyres.
Blame the cheapo camera for making it look orange in the second pic.
By the same token, my old 996 was much better on 17s than 18s - but the latter were absolutely necessary when it came to sell the car on.to this:
Improvements were. More compliant ride, less road noise and improved steering feel. By virtue that they're also narrower all round, the car moves about more under you, understeers less and is far more enjoyable. Now all these differences aren't huge, but they're there and they're noticeable. They're also what come on the car as standard...
It's still too hard IMO, but better than it was on the bigger wheels with rubber band tyres.
Blame the cheapo camera for making it look orange in the second pic.
Edited by juansolo on Saturday 18th February 08:01
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