Below are the full 56 break tests of Farmer Boy 5mm diamond braid polyester cord. The first 40 tests were measured with a LineScale 2 on Peak Fast mode, with soft shackles connecting directly to the dynamometer. Tension was pulled by a single person per test on a 15:1 pulley system with 3" SMC pulleys. Samples were between 2 and 3 meters long, and had a figure 8 knot terminating any end not being tested (on both sides for the bend tests, on one side for the device tests). The final 16 tests were done on Balance Community's break test machine, reading at 500 Hz, which Jerry Miszewski generously let us use for testing.
The cord in this test was about 2 years old and heavily used. Offcuts with notable abrasion spots were avoided where possible, although there was likely significant variation in wear across different test samples. The cord was broken because it was deemed due for retirement, and so represents conservative strength values for used cord.
For full discussion of Farmer Boy, see the main post.
| Break Type | Sample Number | Breaking Strength (kN) | Comments |
|---|---|---|---|
| 8 to 8 | 1 | 2.21 | Broke in middle |
| 8 to 8 | 2 | 2.44 | Broke in middle |
| 8 to 8 | 3 | 2.20 | Broke in middle |
| Alpine Butterfly Bend | 1 | 2.10 | Broke at knot |
| Alpine Butterfly Bend | 2 | 2.18 | Broke at knot |
| Alpine Butterfly Bend | 3 | 2.4 | Broke at knot |
| Double Sheet Bend (Yosemite Finish) | 1 | 2.22 | Broke at knot |
| Double Sheet Bend (Yosemite Finish) | 2 | 1.98 | Broke at knot |
| Double Sheet Bend (Yosemite Finish) | 3 | 2.14 | Broke at knot |
| Releasable Double Sheet Bend | 1 | 2.15 | Broke at knot |
| Zeppelin Bend | 1 | 2.19 | Broke at knot |
| Zeppelin Bend | 2 | 2.02 | Broke at knot |
| Zeppelin Bend | 3 | 2.11 | Broke at knot |
| Micro Trax | 1 | 1.76 | |
| Micro Trax | 2 | 1.54 | |
| Micro Trax | 3 | 1.51 | |
| Doubled Micro Trax | 1 | 2.28 | |
| Doubled Micro Trax | 2 | 2.38 | |
| Doubled Micro Trax | 3 | 2.15 | |
| Mini Trax | 1 | 1.76 | |
| Mini Trax | 2 | 1.54 | |
| Mini Trax | 3 | 1.51 | |
| Doubled Mini Trax | 1 | 2.16 | |
| Doubled Mini Trax | 2 | 2.24 | |
| Doubled Mini Trax | 3 | 2.01 | |
| Roll N Lock | 1 | 1.94 | |
| Roll N Lock | 2 | 1.91 | |
| Roll N Lock | 3 | 2.13 | |
| Doubled Roll N Lock | 1 | 1.93 | Broke notably lower than single wrapped |
| Doubled Roll N Lock | 2 | 1.79 | Broke notably lower than single wrapped |
| Doubled Roll N Lock | 3 | 1.82 | Broke notably lower than single wrapped |
| Handled Ascender | 1 | 1.06 | |
| Handled Ascender | 2 | 1.13 | |
| Handled Ascender | 3 | 1.24 | |
| Chained Handled Ascenders | 1 | 1.66 | 2 in line connected by carabiner |
| Chained Handled Ascenders | 2 | 1.69 | 2 in line connected by carabiner |
| Chained Handled Ascenders | 3 | 1.79 | 2 in line connected by carabiner |
| Tibloc | 1 | 0.99 | Slips, tearing outside |
| Tibloc | 2 | 1.79* | Slips, tearing outside - this test likely loaded the backup rope, leading to artificially high result |
| Tibloc | 3 | 1.00 | Slips, tearing outside |
| Capstan to Capstan | 1 | 4.39 | |
| Capstan to Capstan | 2 | 4.04 | |
| Capstan to Capstan | 3 | 4.22 | |
| Duck | 1 | 2.44 | |
| Duck | 2 | 2.46 | |
| Duck | 3 | 2.57 | |
| Ropeman 1 | 1 | 2.11 | Minor Slippage |
| Ropeman 1 | 2 | 1.78 | Slipped around 1.6 |
| Ropeman 1 | 3 | 1.96 | |
| Spoc | 1 | 2.41 | |
| Spoc | 2 | 2.39 | Desheathed then broke |
| Spoc | 3 | 2.33 | |
| Nite Ize CamJam XT | 1 | 2.87 | |
| Nite Ize CamJam XT | 2 | 2.74 | Slipped before breaking |
| Nite Ize CamJam XT | 3 | 2.80 | Broke at 8 knot |
| 4 Wrap Prusik | 3 | 1.26 | Made of Farmer Boy, Slips |
Alonso's Figure 8 tests show values as high as 3.10 kN for 5mm diamond braid, indicating either that he was using a different brand of cord, or that his cord was less used than mine. My best guess is that my cord was simply more used than his. In the capstan tests, my cord tested as high as 4.04 kN, indicating higher "true" breaking strength in the middle, less used sections of cord. In the devices tested, our results are roughly similar, with minimum values with about .1 kN, or about 5%, across tests. It appears the breaking strength in devices was not highly affected by the wear on the cord.
His tests are spread out across two videos, both below. The first breaks 5mm and 6mm diamond braid in a Petzl Micro Trax and Pro Trax, and the second breaks the same cords in the CT Roll N Lock as well as a figure 8.
I will be trying to keep this page up to date with feedback and new information, and will keep track of edits as I make them here.