The test rig 1) → | Put the shock into the lowest compression damping setting 2) → | Write down the time for all 10 drops; take out the highest and lowest number; then average the times. The average is the time for that dial setting. Rotate the dial 360 degrees, then repeat time collection. Do this until you are at the end. For the compression dial, the last try only move 279 degrees, not a full 360 degrees 3) → |
Plotting the average times per 360 degree rotation yields this graph. You can see, not much happens the first 720 degrees. 4) → | Time to flip the shock and test the rebound damping. Dial back to the lowest rebound setting and paint a reference mark 5) → | Collect the data the same way as the compression testing. The rebound dial only goes around three 360 degree turns. 6) → |
The Rebound damping timing curve 7) → | Put the two curves together and you can see the damping strategy shooting for the highest ratio desired (3.0). You dial in ALL the rebound damping, then dial in zero compression damping. That sets you up with a 2.7 ratio. You can walk in compression damping as needed. I would work in 0.2 ratio increments (can our butts feel 0.1 increment changes??) 8) ✔ |
Article by spacetiger of the XLFORUM 10)
Some early XL1200S test results:
XL1200S rear shock disassembled 16) → | Spring testing using home gym equipment 17) → | Test results 18) ✔ |
The shock after I disassembled it. The threaded portion would not come free, so I setup the band saw to cut just above the threaded portion. I thought I’d have to cut the shock in half, but I only had to cut just below the sleeve and it came free. I had to sand the inner sleeve a bit to get it to fit the XL1200S retainer clip. 24) → | All mounted up and went together nicely. So here it is; 2003 Harley Davidson XL1200S shock body, 1986 Honda VF700C spring, and 2007 Victory Jackpot coil over sleeve. 25) → | Both shocks modified. I was able to assemble the other shock and set the estimated preload for correct sag. Seems I cannot quite get to a sag at 25% and will have to settle for a 31% sag. A bit on the high side, but I will still have almost doubled the working range of the shock. If this doesn't hold up in real world riding, I will have to get some new Eibach springs. ✔ |