WJBertrand
Ventura Highway
Based on the sag number I got, I think Karl hit the 10mm thickness just about right. I noticed that my OEM spring was still a mm or so longer than the Eibach spring sitting on top of the spacer. This means the total preload is maybe a bit less than the OEM spring, but due to the higher spring rate it works out fine. In talking to Sonic Springs, they routinely make their higher rate replacement springs a few mm shorter than OEM to accommodate the higher rate.regulator said:
If I were fitting a lower rate spring, such as the 525 lb/in one I mentioned I might be tempted to make the spacer a couple of mm thicker so that the correct sag could be maintained across all loading conditions. As it stands now, I've not characterized this spring that way so I can't say for sure. With the new spring I'll be running at one-up or one-up + luggage probably 90% of the time. I like having the head room to add a passenger now. I felt before that since I was using almost the entire available pre-load running one up with full luggage that I would overtax the OEM spring adding a passenger with luggage.