All progressive springs mean is that the more the spring is compressed the resistance to compression goes up. The first couple of inches the spring has less coils per inch so it will compress more and smooth out the pavement irregularities without the rider being bounced as bad. In the 80’s and early 90’s progressive springs were the rage for road bikes. Linear wound springs means the spring is wound consistently through its length and compression rate is linear and therefore resistance to compression is the same and that builds resistance to compression. Same size larger bump and the progressive will compress much more before it gets to the stiffer wound section which when off road leads to less ground clearance and therefore smashed belly pans.
With linear springs and better valving internals you will get a more responsive suspension and it will make a huge difference. Just linear springs will and also playing around with the oil viscosity. I have 5 weight in my sports bike and 7 weight in the Tenere and 10 weight in the wings.
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This is a progressive spring from my CBR. See how it is wound tighter on the bottom (left side). I can go down to the barn and get a pic of the stock Tenere spring later if you want to see that. It is longer but basically the same thing. Long but hopefully it helps you visualize the difference.
Happy Thanksgiving!
TG