mpb1 Posted August 29, 2020 Share Posted August 29, 2020 I weight 179lb on the bathroom scale. My bike has the Yamaha Touring Pack with heavy pannier rack and center stand. I was sitting over 70mm sag with the stock spring wound up to max preload. As soon as I saw Rocky Mountain ATV had Rally Raid shock springs I ordered one in 85Nm per Rocky Mountain's chart. The shock drops out the bottom pretty easy if you remove the dog bone rear link bolts and the bottom shock link bolt. I did note that the bolts that go through all the linkage bearings were dry, but they are inside the steel inner races of the bearings, they are not part "of the bearing". Even though the bike is less than 2 months old, the bolts were starting to collect the powdery white corrosion or whatever it is that sometimes builds up down there. The actual needle bearings were greased fine and the outer surface of the inner race tubes were fine. I cleaned up the bolts and added grease between the bolts and the inner race tubes, and added some grease to the bearings because they were right there. I don't have a motorcycle shock compressor, so with the stock light weight spring I just compressed it with two small ratchet straps easily enough on a workbench and got the retainer out without trouble. The new shiny white spring though, I couldn't get to compress with just straps. I had to use my car spring compressors. I didn't think the tangs would fit between the tight (compared to my Ford Raptor) spring coils, but I took the threaded tangs off of the rods and they twisted in just fine, then threaded the tool back together and used the back surface of the preload assembly to brace the nut-side tangs. This worked very well and the spring compressed fine allowing the retainer to slip back in. I did use the plastic collars that came with the spring. One fit tight to the bottom spring cup and one fit tight to the retainer. In free space the new spring by itself was shorter than the stock spring, so with the plastic rings it was the same length. Back together was easier than taking apart. I didn't have a chance to grease the front linkage bolt, because the center stand bracket prevents the bolt from sliding out. If you are installing a center stand this may be a good time to grease that bolt! My sag numbers came right in exactly where I would want them! I was so happy. All of the numbers are with no preload in the adjuster, so I have plenty of room if I'm loaded up for a trip or if I ever ride with a passenger (well, it will help with a passenger, I doubt I could get 60mm sag with two adults on the bike). Using some basic assumptions about linearity, and remember I'm just using a tape-measure, I calculate that I can run 44lbs of payload in the panniers and still see 60mm sag. My 3-day tent camping setup from my last trip put 31 pounds of gear in the panniers, and after some quick "crossing off" I think my next trip will have about 22 pounds of gear, maybe 25. This gives me 19 pounds of capacity for the bike getting full of mud, extra fuel, extra cold-weather gear, extra water, or whatever I think I could possibly need for a trip. I find the Yamaha panniers heavy and the rack to be extra heavy. With a lighter rack and soft-bags, I think I could pick up another 15 or 20lbs of payload. Probably another 2 pounds if I ever get around to a tail-tidy, that is a lot of plastic and glass light bulbs. I think the 85Nm spring is perfect for my average setup! With just me, run the preload at zero, with my normal camping setup, run it about half way, and if I'm really really loaded down with 2 extra gallons of fuel, run it all the way up on preload. That is easy to remember! inches mm percent travel 200 free spring 26.56 675 static 25.5 648 static sag 27 13.5% rider (no preload) 24.25 616 rider sag (no preload) 59 29.4% rider (full preload) 24.91 633 rider sag (full preload) 42 21.0% rider empty boxes (24.1 lbs) 24 610 rider empty boxes sag 65 32.5% lbs mm lb/mm effective sag spring rate 24.1 6 3.80 sag at max preload (empty boxes) 48 desired sag 60 sag available 12 payload available 44.0 5 2 Link to comment Share on other sites More sharing options...
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