Another thing I just thought of is what would be the results if the dyneema rope was dirty as hell and full of sand etc. I bet then the snatch block would edge further ahead .
I love the amount of trouble you've gone through to prove what's known. Hopefully it shuts up some of those wild ideas from those that know they are 100% correct but are wrong. 😂 I appreciate you. 👌
I wish there was a search through comments function in case my thought has been covered. Regarding wear on the soft shackles… if offset rings where used the ring would not rotate…so no wear on the shackle. Of course now the winch rope would wear. However I understand the ropes have a coating which would then become sacrificial. Have fun designing a test on comparing the wear rates between shackles and ropes…! I would think though that in a dirty environment I’d rather the ring rotated lessening sandpapering of the winch rope…replacing soft shackles is always going to be cheaper and much more convenient than replacing winch ropes.
Excellent video! I bought a snatch ring a couple of years ago before they were really known in the off-road industry in North America and was met with nothing but negativity and how they wouldn’t work. Great to see some scientific facts about efficiency comparisons with traditional snatch blocks. Thanks for making the video.
At 2'23" the greatest pun I've seen in a long time. "How the test was rigged." As usual, a very well thought out presentation. The LCD screen on the brick wall is great. Thoroughly enjoyed it and certainly very good food for thought.
Thanks, in my view results don't mean much unless you can show method and data. Every test has limitations, so readers/watchers should be able to judge for themselves.
Great video, but I do think one of the fundamental that was not taken in consideration is the advantage of radius of snatch blocks compared to radius of snatch rings. Greater radius seems to reduce friction.
As a technically-oriented professional, I appreciate your methodologies, presentations, and explanations of conclusions. Well done, thorough, and valid science.
I have a different application: woodland/landscape management. I have to pull some invasive rose and unwanted saplings, without a truck or tractor. I've been using RU-vid University all weekend. The algorithm FINALLY served up your channel, and I want to compliment you: your explanations are easy to understand. I'll be using a come along and plenty of snatch blocks to save my back! Subbed!
Mate, you are a recovery nerd of the highest degree. I mean that as a compliment! Sometimes I struggle to watch the whole vid but I appreciate you posting and sharing the info. :)
Very informative. Have swapped to rings over recent years (Factor 55 and Saber) for reasons other efficiency - weight, space saving and safety. However pleasing to see that I have not lost much in terms of efficiency.
I'm so glad I took the time to watch this video. It makes so much sense now. Thanks for experimenting, data collecting and explaining everything so simply on a subject that can be quite complex :)
This was a surprising and interesting YT video suggestion. Thanks! I have a block and an off-brand ring. The profile of the ring at its root differs from that on the block. The block has a semicircular root profile while the ring's root profile is flatter, with a radiused transition into the sloped guide-channel. The root profile affects how the rope deforms. An interesting test would be how the profile affects efficiency.
Thank you. Your vids are absolutely great. Answered nearly all my questions. I fully expected that the blocks would be the most efficient, but the efficiency of the rings surprised me. The George 4x4 ring seems like the best buy. Looking forward to what you do next.
@@L2SFBC curious if there is a difference between anodized vs polished aluminum vs Teflon coating vs painted. Seems like the George 4x4, the polished aluminum did the best. Also wondering if it makes as much difference as I thought, the overall diameter of the sheeve and the center hole size. Seems like a larger outer diameter and a smaller center hole would be best. Overall I was impressed with the top 3, thanks for the review.
Larger Dd should be best but the Saber was not the top performer. The George is a good buy yes. I think there is a difference between wear on rope and efficiency.
As always Robert, you deliver incredibly detailed and well explained analysis that's easy to digest, and takes a lot of considerations into place. What excites me most about these results, and the evolving technology in recovery equipment is the weight and space savings in your 4x4. Snatch block to rings is a significant space and weight saving. Soft shackles from metal d-shackles is a significant weight saving. kinetic ropes from snatch straps are lighter and can be packed smaller, winch cable to winch rope again a significant weight saving. This is making your load much less, and easier and safer to store in your 4x4 for quick access, and reducing your overall vehicle load.
I'm very happy to had find your video, I was looking for low friction ring use for sailing. Your approach was very informative, and base in facts as much as you could.
Well presented and scientific approach. Well constructed experiment although I wouldn’t have described the results as the rings were half as efficient as the pulley blocks, although you describe it in a better way elsewhere. I would describe the rings as 95% as effective as the puller blocks.
I'm not disputing the results but I would redefine efficiency as (force multiplication divided by force input) divided by two. So a perfect system would be 100%, a block would be 95%, and a ring would be 90%. I would say still that a ring has twice as much loss (Inefficiency) as a block but a ring would have 94.7% of the efficiency of a block.
Great test. Most crucial is to find out who makes "Crap Block". I do think I'll go ahead and add a few rings to my kit in case I ever need to do a reverse winch.
It seems like the natural result is to put a bearing in the middle of those donut things, and a curved insert in that, to produce a compact, low-wear tool. That would certainly tighten profit margins though, so good luck finding one.
@@L2SFBC Yeah, there we go. I like that one, but I suddenly realize that one of those well-developed bearing-rings for the price of 4 of the bearingless ones, for the sake of prolonging the life of my low-grade (cheap) lines, is not very rational. Thanks for the reality check on my "bright ideas".
I think the diameter of the block during the water test played a role in it rotating faster than the ring. Think of it this way... When you do pull-ups on a bar for exercise, it's easier to get a grip on the bar when the bar is thinner and when the bar is thicker, requires more grip strength. Likewise with the water test, the rope has a sharper angle of return to the load because of a shorter sharp return around a smaller diameter ring.
If you put the load cell on the final side of the rope where it anchors to the truck it would just be the opposite side of the pully and it would be the lower of the two measurements instead of the higher side but the math still works the same way just opposite!
I had wondered about this. I had the idea that with the rings generally synthetic rope will flatten & make more surface area contact, both with the line & the soft shackle, so of course more resistance & so friction. I have little experience, I am only getting started with familiarizing myself on recovery. My observations have mostly been what I have seen on YT. I had thought that as a general rule snatch blocks were designed for steel cable. I had heard some online state that the rope used with the snatch blocks would be more inclined to damage the synthetic line. So I was a little surprised to see you use the synthetic rope with the blocks. To my mind a an improved snatch block design to be uses with the synthetic rope would give a little better efficiency & wear. A wider pulley that is machined with a gentle valley & rounded edges & so to rounded edges on the 2 closing plates of the block. The pulley turning on a pin similar to a conventional block. I am yet to see anything like this on the market design wise that goes in this direction. The Philosophy seems to be more focused on weight saving. That is not a criticism, only an observation. I guess any improvement in efficiency & wear is probably not going to be that much better , so the cost of design improvement is probably going to give a huge cost for little improvement. But this video has kind of swayed me from going & buying a ring & soft shackle & maybe machining up my own wider pulley to test what I have suggested here.
The blocks I've seen have a good sheave diameter, and groove for synth rope. Yes rings are about weight, cost and bulk saving. And yes, I agree that given blocks and rings are so close, there's not much point trying to create a better ring..the gains are marginal. However, I would think there is some work to be done around care of rope. But, that needs a lot of testing! Interested to see what you come up with.
We have pulleys on our shoes! Look at the way shoelaces go through eyelets and when we pull to take the slack out, boom, great tightening ability. Distance traded for power.
What a great test. The result was on with what I felt as the test result came out. Question I was wander when you tested the rings I lost track of the rings different sizes so with that I was wandering if the bigger ring having more surface area, making the rope travel farther vrs the smaller ring with less surface area add in the resistances with the given load in addition heat of the rope sliding over the ring . I think you have the data already but would be interesting if a larger ring would be more or less effective than a small ring when under load I like the snantch blocks with bearing myself but the the ring block does have advantages over the long run in weight and space and at the end of the day they just work Thanks for doing the test !
Now this is a good video done correctly! The water test shows that the friction of rings increase with load at a higher rate than the block does. Again the difference between bushes and bearings. More load requires less friction. The blocks i would assume failed at this one because of the actuall weight of the block wheel over the weight of the ring causing what looks like more friction but is actually more dead weight
If you were to spin both a block and ring on a steel shaft the block would take considerable more force to get started than the ring. But with that inertia the block would spin for a lot longer time
With the water test the loads are very low and the friction would NOT generate heat in the rope - heat in the rope will INCREASE the friction as the plastic becomes stickier/gooier - which is not happening in the water test, whereas the blocks have "stiction" - ie, static friction, a release force, which peaks, and then drops once moving, hence the reversal in roles.
Should have put the load cell on the final side of the rope where it meets the truck after the pully . Then it doesn't move and would not need to worry about the load cell getting to close to the pully or the winch .
@@L2SFBC I it makes sense however cable manufacturer recommend the pulley to be at least 5x the diameter of the rope or cable to reduce the load on the rope or cable. Some even recommend 10x for cable.....that would make a 200mm pulley for 3/8 cable. Almost twice the size of the ones tested.
Important to note that if you're pulling with, say even a 500 lb force, then 0.2 efficiency drop is 100 lb less pulling force so the difference is significant. You start pulling with a even a small 2,000 lb winch that turns into a 400 lb loss of pulling force. So that's 100 lb less force for a couple guys pulling a rope. 2,000 lb winch = 400 lb difference in max force. 5,500 lb winch = 1,100 lb difference 12,000 lb winch = 2,400 lb difference. Definitely a decent sized loss. Might be better to go one more decimal point to compare better. About a 10.53% difference in the total output in the end between a 1.7 and 1.9 on your scale.
@@L2SFBC That makes perfect sense if you're measuring devices aren't anymore accurate than that. Thanks for the response & the video. It's still very helpful even at that accuracy.
Looking forward to checking out your channel more. Over from Mad Matt 4wd's 80 series recovery. Great information on this video, I was just discussing this with Matt
Great testing Robert with a scientific means of measuring the total load on the anchor and the load on each of the ropes either side of the Snatch Block. I do wonder though how there is a similar lineal load difference of results on "Test ! " right across the whole test and especially during the "Rest" in the middle of this winch episode. I would have thought the load cells two lines Orange and Green would have converged at this point! I have an identical snatch block used in test 1 purchased from TJM around 1984, mine is a bit more bent and buckled though. Interesting the Ridge Rider Snatch Block had the pin rotating in the housing thereby not allowing the pulley to rotate on the pin with a bigger surface load bearing area and may have contributed a greater frictional loss. The old wire rope scenario still rings true though of the radius the wire rope has to go around a pulley - the bigger the diameter pulley means the rope doesn't flex and bind with friction more between individual wires or strands which will shorten the life of the rope.
That was interesting! Same phenomena but so much less losses with slippy dyneema than something like static rope that can have 50% efficiency when using a normal carabiner as a pulley and 10% loss being typical with good pulleys like used in climbing/rope access or rescue (figures from another video that had measurements for some perticular gear). Understanding those can be good in case you have to use multiple pulleys. Use the best was in the beginning and not so good ones later on closer to fixed end. Another interesting one to measure would be a 3:1 or 4:1 with two rings: you can route the rope first normally and through the middle hole the second time (as long as there is room not to rub the soft shackle at the other end of same hole).
@@L2SFBC With very slim rings it would be an issue but most are something like an inch wide that is already multiple time something like 8mm rope. Much more than a typical shackle. I wish I had a load cell for testing stuff like that myself but they are so expensive!
So, in reality, the most critical aspects are The weight difference between rings and blocks. (Recovery gear can add up to a significant weight penalty on your 4x4) The volume difference (storage volume, always limited on your 4x4) Long term reliability / durability of soft / hard shackles and rings / blocks. price. (this would also need to include the fuel penalty for hauling your recovery gear all over the place)
The biggest issue that I am hearing about with the pulley blocks is that when the rope goes slack, it is quite easy for the line to jump out of the channel. Then when the person goes to winch, the line pulls tight against the soft shackle and cuts through the soft shackle. F55 has the best solution so far, but it still allows the line to fall out too easily. If someone is going to go the pulley route, make sure you have more than 1 soft shackle that is rated for use with the pulley. I will keep my ARB pulley block. It weighs a bit more, but I don't need to worry about the line falling out.
@@L2SFBCI think the problem is mainly with pulls that are redirects on an obtuse angle. A 180° or acute angle pull is the best case scenario for rope retention and why you haven't seen the issue.
Excellent video...again. I have just bought 4 rings to replace my 4 blocks in my Self Recovery Kit. Basically using mechanical advantage I can 'winch' myself out manually. The big issue was weight with the 4 blocks weighing in around 12kg. Now the 4 rings wipe more than 10kg off that. I have basically taken a 14kg kit down to under 5kg. This leaves weight-room for my chain and rebar ground anchor. Your videos have helped me considerably; especially with the maths and safety considerations. I've seen the results of recoveries gone horribly wrong in the Army so I'm well aware of what I don't know and your material has filled a few gaps. Thankyou. Aside from that... you resemble a man my Dad served with in the RAF FEAF Band in Singapore in 1968-70; Fred Pepper. Any relation?
@@L2SFBC When I do my update video on my self recovery system I will certainly link to your channel and give a shout out for the value your vids have been. The physics are vital and your vids explain them in terms anyone can understand; which of course is what good communication is all about. I only invested in the extra snatch blocks and rope after studying your winch videos and gaining the confidence my idea would work. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE--YhEN8ZPD6I.html
Thank you Robert. I was one of those vocal about the inefficiency of the rings, so I'm pleased to see a well designed test that proves me wrong. I'm also interested to see that, as with so many cases, more expensive doesn't mean better. I wonder if winch speed affects the efficiencies? Would a high-speed competition winch, pulling at higher speed, show a greater difference in efficiencies, or if the ratios would remain the same? Probably not of great practical significance, and I doubt the competition guys would be too concerned either way.
Thanks Scott - comp winches would be different as you say due to higher speeds, and greater duration of winching. I noticed some heat buildup - more on that later. Recreational winching is typically 2000kg or under, and 30 seconds on/off, maybe more. So quite low stress. Important to understand the application before selecting gear.
@@L2SFBC Thanks Robert. When you do triple line pull, will you also test sequence i.e. one will turn faster than the other, my gut feel is to use block for the higher speed, and ring for lower speed. Would be interested if there's a practical difference, but not sure how you'd test?
I'm not sure how you calculated efficiency. But I think that you meant the following: If the efficiency of a pulley were 90%, then if the tension on the winch line were 1 ton, then after passing through the block, the tension on the other side would be 90% of a ton or .9 ton, and total force on the anchor would be 1.9 tons. If it were pass through a second block, the tension then would be .9X.9 = .81 ton. So I think you're saying the average efficiency of the blocks is 100% - 4.5% = 95.5% and the average of rings would be 100% - 7.5% = 92.5%. If total tension on anchor is T, tension on winch is W, and tension on line after block is B, then W+B=T and efficiency would be: Efficiency = B/W = (T-W)/W . Please let me know if I got it wrong. Thanks for a very interesting video!
Brilliant video. Looking at the variety of blocks and rings do you think the diameter of the rings/blocks would have an effect on the efficiency? I really enjoy learning from your videos.
Thank you for the efforts and the educative videos. I really like them and enjoy watching them several times. I do think, however, that in this particular video, you didn't pay enough attention to the diameter of the different rings and hence the efficiency calculation got slightly diverted.
Don’t have to watch video to tell which is most efficient just depends on what you have in your bag. I run a steel cable so I got plenty of block it’s all I have
I think the diameter of the pulley is a significant factor, less rotations for the same amount line pulled in, the force is further away from the center of rotation and the line doesn't bend as sharply.
As always. A very informative and well delivered analysis. Would you consider doing a video on the best way to jump start a 4WD given there are so many different ways, but I'm not sure the right way to do it for my car. Thanks again.
When you have a Patrol kitted out, every gram counts. So the snatch blocks are out the door, and the rings are in. Snatch blocks are so called because they can readily remove chunks of your appendages, and they can destroy wire or rope cables when the inevitable slip off the side occurs in the middle of a seriously difficult recovery. I'm pleased the George one is good, as that's the one I purchased :)
The place to save weight is not in your recovery gear. There are literally hundreds of other places and specification choices that have a larger influence than the weight of a couple blocks.
Excellent video with good engineering principles exhibited in the testing. Answered exactly the question I have been wondering - does the added friction of the snatch ring noticeably reduce efficiency? Great job, Robert!
This is great material Robert. I would be interested in seeing cable run through the snatch blocks vs synthetic rope. Also, the old beat up pully being most efficient begs the question if they have a break in period. Perhaps it ran smoother because it was used more and is past a potential break in period.
You mean wire rope? Interesting point. Suspect that would be harder to bend and require more winch load but am not sure I could measure accurately enough. The ARB block has been used enough to break in as well...I do not have a good explanation other than maybe sheave radius.
@@L2SFBC yes, wire rope / steel cable. It would be an interesting comparison the way you are tracking the data through the pull. There remains some debate between the 2 types of rope. I continue to use steel because where I off-road often has a lot of jagged rocks and in the winter concerns over a wet synth rope freezing on the spool. I would suspect the loading and unloading through the total pull might look different due to less stretching of the steel cable. Yes, I could see the potential more energy needed related to the steel confirming to the snatch block.
Wow, great content! Both sound engineering tests and clearly presented. Also, “the test was rigged” 😁 And where can I get a “crap” block 😉 Cheers from California!
