I have been getting good information from Rokslide for a few years. I just joined so that I can hopefully help someone with the common Eberlestock F1 Mainframe load lifter issue. The regular length frame without modification is very durable and great for under 40 pounds. It starts to get uncomfortable at 50 pounds, and is unbearable at 70 pounds. The load lifter modification combined with a few other tips I'll give make the frame comfortable enough for me up to around 90 pounds.
Using 1/2" PVC pipe, I created the frame as shown in the attached photos. I used white PVC primed with purple PVC plumbing primer prior to spray painting. Makes the spray paint adhere much better than bare. You could also get gray PVC, which would be nice. There is a lower aluminum cross-bar on the mainframe that accepts the slots in the ends of the PVC pipe. The holes in the ends of PVC pipes allows the PVC frame to be attached to the lower crossbar using paracord. The laser cut MOLLE panel really locks the PVC frame in tight and there is no motion up/down, left/right, or in/out. Much tighter than I would have expected. The buckles were attached using 7/8" wide Velcro straps from Home Depot. These eliminated the need for sewing straps and they work very well.
In addition to the load lifter modification, I also noticed a few other things that help with heavy loads. There is about 1" of up/down adjustment where the hip belt Velcro is captured under the lumbar pad. I put the hip belt as low as possible. It does not slip up even though it is held by Velcro alone, since the Velcro is pushed together tightly under load. I also noticed that the standard hip belt reduced the slippage over my hips. I adjust the hip belt over my hips and it pulls down slightly into the correct position under load. It seems the upgraded padded hip belt is too thick and soft that it requires too much force to keep from slipping for me. No slippage with the standard belt. Also, I do not use the load shelf as it is too low and puts too much pressure on my lower back. Using crossed compression straps, the load can be elevated much higher than the load shelf. This makes a big difference for me in the ability to comfortably handle heavy loads.
Hope this helps.
Using 1/2" PVC pipe, I created the frame as shown in the attached photos. I used white PVC primed with purple PVC plumbing primer prior to spray painting. Makes the spray paint adhere much better than bare. You could also get gray PVC, which would be nice. There is a lower aluminum cross-bar on the mainframe that accepts the slots in the ends of the PVC pipe. The holes in the ends of PVC pipes allows the PVC frame to be attached to the lower crossbar using paracord. The laser cut MOLLE panel really locks the PVC frame in tight and there is no motion up/down, left/right, or in/out. Much tighter than I would have expected. The buckles were attached using 7/8" wide Velcro straps from Home Depot. These eliminated the need for sewing straps and they work very well.
In addition to the load lifter modification, I also noticed a few other things that help with heavy loads. There is about 1" of up/down adjustment where the hip belt Velcro is captured under the lumbar pad. I put the hip belt as low as possible. It does not slip up even though it is held by Velcro alone, since the Velcro is pushed together tightly under load. I also noticed that the standard hip belt reduced the slippage over my hips. I adjust the hip belt over my hips and it pulls down slightly into the correct position under load. It seems the upgraded padded hip belt is too thick and soft that it requires too much force to keep from slipping for me. No slippage with the standard belt. Also, I do not use the load shelf as it is too low and puts too much pressure on my lower back. Using crossed compression straps, the load can be elevated much higher than the load shelf. This makes a big difference for me in the ability to comfortably handle heavy loads.
Hope this helps.
