Copied from an earlier post of mine:
.... Snip.....
I understand where you are coming from with this, but you can't think of it as stiffer v/s softer when were talking a change in the linkage effecting a change in the perceived spring rate.
Statement to consider: All sportbike shocks have linear rate springs fitted as standard. Considering the loads and the short length of the spring on a rear shock, tuning a progressive rate spring is difficult, costly and would further distance road bikes from their track brethren, so not really an option. Therefore, all sportbikes, unless purpose built for the track, have a progressive rate linkage and a linear rate spring on the shock.
Think of it this way:
Having the option on the Panigale, with the linkage is set to the linear (Flat) position, the linkage acts directly on the spring. This is oversimplifying it a bit, but with a linear rate, if it takes 50Kg to compress the suspension 1 inch, it will take ~ another 50Kg to compress the suspension a further 1 inch and so on till the you reach the limit of available travel. This is fine if you're on a smooth track, but on the roads, bumps can cause the rear compress much further, which soaks up the bump, but then it will also have to rebound further, which can cause one to feel like they are being slapped in the bum with the seat. You might think "well just adjust the rebound and compression to compensate" however, unless you're at a comparatively smooth track, this is very difficult to get right for the road as every road and bump is different. I've seen more than one person trying to tune a linear rate setup for the road which resulted in suspension packing - where the suspension never fully rebounds while going over washboard roads, which can effectively lock out you suspension making it feel board stiff over rough sections. Another problem is that folks with flat rates, being familiar with progressive rates all their riding lives, usually end up setting the preload spring rate harder to reduce the new found suspension travel and rebound effect.
With an standard progressive rate suspension, as the rear compresses, the spring rate rises and thus the spring effectively feels as if it has more resistance as it compresses. Oversimplifying again, if it takes 50Kg to compress the suspension 1 inch, it may take another 65 Kg to compress the suspension 2 inches and another 80Kg to compress the suspension 3 inches and another 110Kg to compress the suspension 4 inches. In these examples with a linear rate setting, it would only take ~200Kg of force to compress the suspension 4 inches where with the progressive rising rate setting, it would take ~ 315Kg of force to compress the suspension the same 4 inches.
Even considering setting proper sag, usually with a progressive linkage setup, you can start with a slightly "softer" initial spring load than you can with a flat rate as you have the rising rate of resistance as the suspension compresses to keep things in check.
However, I think the most important and final thought to consider is: Most of us that ride roads, even if we do a lot of track riding, are more familiar with the reaction of a progressive linkage setup and will therefore inevitably feel more at home with a progressive setting out of the box. I try to spilt my riding into 50/50 track and road, though the fist modification I performed on my Panigale was to change the linkage from Flat to the familiar progressive setting.
Is flat for the track and progressive street? I'm taking mine in for her first service next weekend and if this is they way to go I would like to have them change it.
