Originally Posted by MaysEffect

Ok, but how much stiffer? 25% stiffer? 75%?

It's directly proportional to how stiff the bar is compared to the spring rate and corner weight. Its all guess work unless the manufacturer of the asb states exactly how much force it takes to bend the bar, which absolutely no one does. At max, some companies may give you a percentage compared to oem. If you get a bar that has a greater resistance to bending than the spring rate, you may end up exerting too much force on the tires. This again goes back to the level of grip the tires can make. You may reduce the sensation of roll, but this doesn't garranty more grip. Where it may give an increased level of force to overcome traction loss, you run the risk of overloading the tire at the limit and having a sudden loss of traction when the tire lets go, compared to a gradual loss of traction. I personally wouldn't do this change alone unless i have a tire that can support a higher load rating. Presumably double that of the corner weight.

But i think we all can agree, the first modification to ever be done is tires. Only then should you decide to change the ASB and/or spring rate.