This page contains LENGTH SPECIFICATIONS for JRB knots and designs. See these dedicated pages for details on these items:
Relevant video:
More is better than less: Whether its cord or webbing, please error on the side of purchasing and cutting a little extra. For example, if you think you need 12 feet of cord for two 6 ft lengths, buy at least 14 and cut and tie using 7. Get it tuned up perfectly and then trim the tails or retie at the perfect length later.
Note: the tables below do not have entries for 9mm ropes. My “9mm” Canyon Elite measures closer to 10mm, so just use the 10mm lengths as a reference if you use that rope. You can always trim a bit if necessary.
JRB Ascender Hitch, 523, Soft Bridge Mode
See the video, table and image to understand the 523 JRB Ascender in Soft Bridge Mode and how the measurements are taken in the reference examples. Note: if the auto-tending feature is desired, it must have 2 loops exposed. Working End #1 is the length of the working end used to form the friction hitch from where the cord is first laid over the rope, and supplies enough cord to tie the main portion of the hitch. From the reference information in the tables below, we can calculate the cord necessary to make longer or shorter loops. Examples:
- For single loop 2in longer: 2 x 2 = 4in more cord
- For single loop 3cm shorter: 2 x 3 = 6cm less cord
- For double loops 3in shorter: 4 x 3 = 12in less cord
- For double loops 5cm longer: 5 x 4 = 20cm more cord
| Cord & Rope | Total Cord Length | Standing End | Working End | Single Loop Size | Double Loop Size |
| 6mm on 8mm | 60 in 152cm | 26 in 66 cm | 34 in 86 cm | 10 in 25 cm | 5 in 13 cm |
| 7mm on 8mm | 72 in 183cm | 34 in 86 cm | 38 in 97 cm | 12 in 30 cm | 6 in 15 cm |
| 7mm on 9.5mm | 72 in 183cm | 32 in 81 cm | 40 in 102cm | 12 in 30 cm | 6 in 15 cm |
| 8mm on 11mm | 84 in 213cm | 38 in 97 cm | 46 in 117cm | 14 in 36 cm | 7 in 18 cm |
Note: If using a Longhorn Hitch instead of a Hunters Bend, approximately (12 in / 30 cm) is needed on each side. More accurately, take the Reference cord length and then add 2x the Single Loop Size. For 6mm on 8mm, use: 60+10+10 = 80 in
Note that when using the Longhorn Hitch, there is no option for a double loop. Single loop only. Also, it’s important to get the JRBAH loaded and tuned first using a Hunter’s Bend, then remove the Hunter’s Bend and replaced with the Longhorn Hitch.
JRB Ascender Hitch, Non Jamming
This variant is my preference for JRB Hitch Climbing.
Note: if the auto-tending feature is desired, it must have 2 loops exposed. Working End #1 is the length of the working end used to form the friction hitch from where the cord is first laid over the rope, and supplies enough cord to tie the main portion of the hitch and enough on the end to tie the flat overhand bend AND a stopper knot. The stated sizes of the loops produced are approximate and will vary a bit based on your cord, rope and the details of the tie.
| Cord & Rope | Total Cord Length | Standing End | Working End | Single Loop Size | Double Loop Size |
| 6mm on 8mm | 72 in 183cm | 36 in 91 cm | 36 in 91 cm | 9 in 23 cm | 4 in 10 cm |
| 6mm on 8mm (compact) | 60 in 152cm | 23 in 58 cm | 37 in 94 cm | N/A | 0.5 in 1 cm |
| 7mm on 8mm | 84 in 213cm | 45 in 114cm | 39 in 99 cm | 12 in 30 cm | 6 in 15 cm |
| 7mm on 8mm (compact) | 64 in 163cm | 25 in 64 cm | 39 in 99 cm | N/A | 0.75 in 2 cm |
| 7mm on 9.5mm | 84 in 213cm | 42 in 107cm | 42 in 107cm | 11 in 28 cm | 5 in 13 cm |
| 7mm on 9.5mm (compact) | 72 in 183cm | 26 in 66 cm | 46 in 117cm | N/A | 0.5 in 1 cm |
| 8mm on 11mm | 96 in 244cm | 50 in 127cm | 46 in 117cm | 14 in 36 cm | 6.5 in 17 cm |
| 8mm on 11mm (compact) | 72 in 183cm | 26 in 66 cm | 46 in 117cm | N/A | 0.5 in 1 cm |
JRB Ascender Hitch, Compact, version 3
This variant is my preference for a footloop, or auto-tending, progress capture MRS/DRT systems, or a tether or any other compact variation.
| Cord & Rope | Total Cord Length | Standing End | Working End |
| 6mm on 8mm | 60 in 152 cm | 15 in 38 cm | 45 in 114 cm |
| 7mm on 9.5 mm | 72 in 183 cm | 20 in 51 cm | 52 in 132 cm |
Agile Hitch
The Agile Hitch is constructed using a cord, which is approximately 65-75% of the diameter of the rope.
Minimum Lengths
The sizes below are minimums to tie a 5 wrap hitch, yielding a minimal length load loop, closed with a single bend. In order to build with a longer loops, for every additional inch of desired length, add 2 inches to the overall length. In general, it is recommended to cut more, then tie and trim to reduce to desired lengths.
- 6 mm cord on 8 mm rope: minimum of 60 in / 152 cm
- 7 mm cord on 9.5 mm rope: minimum of 66 in / 168 cm
- 7 mm cord on 11 mm rope: minimum of 72 in / 183 cm
Recommended Lengths for JRB Doubled Rope
In the JRB Double Rope system, we want our friction hitches to have a load loop of approximately 12 in or 30 cm. Add 24 in or 60 cm to the lengths above. Tie and trim if necessary.
- 6mm cord on 8 mm rope: minimum of 84 in / 213 cm
- 7mm cord on 9.5 mm rope: minimum of
- 7mm cord on 11 mm rope: minimum of 96 in / 244 cm
Longhorn Agile Hitch
The Longhorn Agile Hitch is constructed using a cord, which is approximately 65-75% of the diameter of the rope. The sizes below are minimums to tie a 5 wrap hitch, yielding a compact hitch with minimally sized load loops. In order to build with a longer pair of loops, for every additional inch of desired length, add 4 inches to the overall length. In general, it is recommended to cut more, then tie and trim to reduce to desired lengths.
- 6mm cord on 8 mm rope: minimum cord of 72 in (183 cm), using 12 in (30.5 cm) working ends for the Longhorn, and a 17.5 in (44 cm) loop to form the Longhorn Agile.
- 7mm cord on 9.5 mm rope: minimum cord of 84 in / 213 cm, using 14 in (35.5 cm) working ends for the Longhorn, and a 20 in (51 cm) loop to form the Longhorn Agile.
- 7mm cord on 11 mm rope: minimum cord of 96 in / 244 cm
Longhorn Friction Shackle
For 9.5 mm rope, use 72″ of 6 mm cord; start the Longhorn with 16″ working ends.
For 8 mm rope, use 72″ of 6 mm cord; start the Longhorn with 17″ working ends.
Longhorn Soft Shackle
Using 7mm cord, a 72 inch (183 cm) with 20 inch (51 cm) working ends produces a shackle that is about 7 inches (18 cm) long, measured from end to end, when closed.
Using 6mm cord, a 60 inch (152 cm) with 16 inch (41 cm) working ends produces a shackle that is about 5 inches (13 cm) long, measured from end to end, when closed.
If we need the shackle to be longer by X, add 4X cord to the cord that is used. For example: We need to build a 7mm shackle that is 16 in long when closed:
- 16 – 7 = 9 inches more needed on each strand.
- 4 strands x 9 inches = 36 in
- 72 in + 36 in = 108 in