It's interesting how assumptions get made about what one understands and how one applies information. As it turns out, when I replaced my OEM shocks with Hagons, I really didn't have a complete understanding of what I was doing and why - I knew that the ride was harsh and uncomfortable, and I followed advice to try to improve things.
After a bit of back and forth, Dave Quinn recommended 18kg springs. I installed them, but I didn't really think the ride was that much improved. This last month, I tried 16kg springs, and as much as I wished for it, I couldn't honestly say I'd improved things much. Now, he's trying to help me get it sorted.
He suggested I slide what he calls the "over-stroke rubber bump stops" down to the tops of the damper bodies, to see how much travel I'm using. I didn't even notice those things were there until I changed the springs!
Anyway, I have the 16's at the softest preload setting, and I slid the bump stops down, and I rode to work - mostly little rattly bumps which try to shake your fillings loose, but a couple proper frost heaves which made me, and my back, take real notice. When I got to work, I found the stops hard up against the top of the shaft. This means that the shocks are bottoming out... which is what I figure we don't want.
On my ride home, I pushed the stops back down, and rode just a quarter mile of the little rattly bumps, and I stopped to look at the shocks again, and found the stops less than an inch from the top. So to me, it seems as if those 16 springs with soft preload aren't cutting it - I'm talking here about just me and a fairly lightweight backpack, no bags or other cargo.
So now I'm thinking about the 18's again - when I went through the motions of changing those springs, the stops were at the top of the travel, so I assumed that I didn't have a useful indicator there, but Dave says that when he builds shocks, he ships them with the bump stops pressed down against the shock body. He also says, if the buffers were at the tops of the shocks when I removed the 18kg springs, it suggests I was bottoming with them as well.
So in theory, the cause of at least some of my discomfort could be that I've never had stiff enough rear springs. Now I'm not a heavy guy - does it seem likely that at 170 pounds locked and loaded I should be bottoming out 18kg springs?
Anyway, I'm going to reinstall the 18's, drop the stops and ride a bit to see what happens. I did take a couple of longer rides last year with some luggage, without changing preload settings, which could have made the difference and bottomed out the 18's. It could be that they're perfect for me after all, travel-wise... but that means that I've still got a rough-and-tumble ride. Only my sprung solo seat has made things bearable thus far.
The things we learn...