Code Red
Adventurist
OK, so I am moving into the 21st century and have become interested in Bubba Ropes or KERR's if that sounds better.
Specifically, I am interested in sizing. My understanding is that a KERR is simply an improvement performance-wise on a snatch strap. It will provide some elasticity to absorb the shock and use that stored energy to assist with the pull.
I have heard that a 3:1 ratio is good, so a 19,000lb KERR seems appropriate for my 6,500lb 70 series. My understanding and experience with straps is that buying too big a strap means that you will get a lot less of the available stretch because it takes more force to get it there. Higher rated straps tend to absorb proportionately less shock and transfer it to the tow points where bad (i.e. more dangerous) breakage can occur. This is all seat of the pants impression, but it makes sense to me.
I am also conscious of the weakest link approach, and I would prefer the nylon KERR break before the tow point parts company with the vehicle. 20,000mph nylon is scary, but 20,000mph shackle and a tow point is scarier.
I have only used these things a couple of times, and was impressed with how smooth the recoveries were. The reduction is shock load seems to me as if it will be easier on the equipment, and provide less risk of a flying tow point that a stiffer strap does. I don't have the education or physics background to know if that's true, but it feels right. Out here in the desert, we are also in love with towing solutions that don't rely on the tow vehicle having a lot of traction.
My question is about capacity. I have had no issues doing the things I do with snatch straps rated at 8,000KG (17,600lbs). So I am inclined to think that the 19,000lb KERR is about the right size. But I have never seen anyone using one that small. The original Bubba Rope is 7/8" and rated at 28K. The smaller "renegade" model is 3/4" and rated at 19K and advertised as being for "jeeps and small trucks."
Is 19K about right? Is 3:1 a realistic rule of thumb for these things?
Specifically, I am interested in sizing. My understanding is that a KERR is simply an improvement performance-wise on a snatch strap. It will provide some elasticity to absorb the shock and use that stored energy to assist with the pull.
I have heard that a 3:1 ratio is good, so a 19,000lb KERR seems appropriate for my 6,500lb 70 series. My understanding and experience with straps is that buying too big a strap means that you will get a lot less of the available stretch because it takes more force to get it there. Higher rated straps tend to absorb proportionately less shock and transfer it to the tow points where bad (i.e. more dangerous) breakage can occur. This is all seat of the pants impression, but it makes sense to me.
I am also conscious of the weakest link approach, and I would prefer the nylon KERR break before the tow point parts company with the vehicle. 20,000mph nylon is scary, but 20,000mph shackle and a tow point is scarier.
I have only used these things a couple of times, and was impressed with how smooth the recoveries were. The reduction is shock load seems to me as if it will be easier on the equipment, and provide less risk of a flying tow point that a stiffer strap does. I don't have the education or physics background to know if that's true, but it feels right. Out here in the desert, we are also in love with towing solutions that don't rely on the tow vehicle having a lot of traction.
My question is about capacity. I have had no issues doing the things I do with snatch straps rated at 8,000KG (17,600lbs). So I am inclined to think that the 19,000lb KERR is about the right size. But I have never seen anyone using one that small. The original Bubba Rope is 7/8" and rated at 28K. The smaller "renegade" model is 3/4" and rated at 19K and advertised as being for "jeeps and small trucks."
Is 19K about right? Is 3:1 a realistic rule of thumb for these things?
