The logic is as follows.
Yes you can soften the springs and dampers and get a more comfortable ride but that leads to more body roll on cornering and more reaction to side winds etc.
The physics are quite simple. It takes more energy to deflect a heavier object. Surely that is a given.
So therefore a heavier car will be less deflected by a speed bump or pothole. The shock absorbers / springs can thrn dampen the effect.
A lighter car is deflected by the bumps more because there is less resistance to the deflection.
Drive a large truck loaded with cement over a small pot hole. Then go over it in a light vehicle ( or even a motorcycle) and the difference is huge.
So all that I am saying is that it is pretty much unfair to criticise the A2 suspension (ok apart from the sport, but that is meant to be stiff). Because the figment of softer springs and shocks (to get a better ratio of weight of the car compared to spring rates) would give you a ride that would make you sea sick.
Even the best suspension designer in the world could not make the ride of the A2 softer without sacrificing cornering and stability.
Fitting larger profile file tyres does help a little, but one important thing to remember about tyres is that they are effectively a spring with no damping effect. So compress one over a pothole and you will get a rebound. The lower profiles don't compress so much but they also have less rebound. This CAN be felt in the car.
You can see this by droppings wheel and tyre from a set height. The lower the profile tyre the less rebound there is.
But I agree with organises of this debate because if you fit higher profile tyres and you FEEL that they give a better ride, then that is all that matters.
So there is no right or wrong when it comes to a firm ride. Some people prefer a softer tide others (me included) prefer a firmer ride
Steve B
That logic is still flawed. The only object being deflected is the wheel and suspension (the unsprung mass), which itself is imparting energy to the rest of the vehicle (the sprung mass). The energy imparted to the vehicle is only by means of the movement of the wheel and suspension in response to road imperfections, and the force required to do so. A heavier car is more likely to have a higher spring rate to support the car, therefore the same bump presented to a heavier car will typically present a greater force to be balanced by the car's weight.
If a car is deflected it is therefore always due to some imbalance, however small or large, in the forces exerted by the unsprung masses on the vehicle's sprung mass.
In regards to cornering and stability, these are considerations related more to the centre of gravity of the car, the roll centres front and rear, and the dynamics of weight distribution. It is certainly feasible to have soft(er) suspension and a high resistance to roll with the benefit of anti-roll bars (which in some cars are hydraulically substituted), due design consideration of roll centres, and also through certain types of suspension design (e.g. De Dion).
Consider therefore that the imperfections of the road are transmitted to the car by two springs in series: 1. The tyre, and 2. The suspension. The tyre does have its own damping effect (if it didn't, it would never stop bouncing.. not a boon for any F1 car), and so does the suspension.
Importantly, the force of any bump will first be transmitted to the tyre, which will transfer any excess force to the suspension... and vice versa on the rebound.
So, the benefit of higher profile tyres is that they can provide additional spring capacity to absorb smaller bumps, potentially in an improved manner to the suspension alone. This can be considered as an improvement in secondary (small bump) ride quality. The suspension will still however provide the same primary ride quality for body control and larger bumps.
Together, the tyre and suspension work as a system. By contrast, if the tyre had a non-existent profile, it would force the suspension to balance all of the road forces the car, and sometimes this can improve ride quality - especially for body control and larger bumps - as the forces will act and be controlled mostly through the suspension. I have experienced this going from 17 to 18 inch wheels on a Saab 9-3 after fitting Eibach Pro lowering springs.
So.. the key is for both the tyre and suspension to be matched to provide the desired ride characteristics, which is why a lot of effort and hours go into such development, and why sharing experience in an objective, consistent manner can be of benefit.
I am certainly not looking to start another debate, however there are no fundamentals which consign the A2 to a particular envelope of ride quality on technical grounds.
I'd suggest that the means to addressing A2 owners' ride quality concerns is not as simple as a firm or soft preference and camps thereof; it requires a holistic consideration of primary (body control and big bumps) and secondary ride (road imperfections) preferences, and using that understanding and experience to match tyre and suspension to function as a system. For example, improved body control *and* better small bump absorption on an A2 could technically be possible with soft suspension, firm dampers, and low profile tyres..
I agree that each may have his or her own preference, but a better understanding of the contributing factors would not hurt, and the following link is very useful to demystify such things:
http://www.rapid-racer.com/suspension-tuning.php
