Length Spec’s

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.


Longhorn Agile Hitch

Tying the Longhorn Agile Hitch

The Longhorn Agile Hitch is constructed using cord which is approximately 65-75% of the diameter of the rope. The dimensions below are when tying a 5 wrap hitch, whereby the last column specifies the approximate length of the resulting 2 “load-loops” produced. In order to create a longer pair of loops, for every additional inch of desired length, add approximately 4 inches to the overall cord length. In order to fine tune the length of the loops to a smaller size, increase the working ends of the starting Longhorn. In general, it is recommended to cut a bit more cord than necessary, and trim any extra later.

Cord / Rope Cord LengthWorking Ends for LonghornWorking Loop to start LAResulting
Double Loops
6mm / 8mm72″
183
12″
30.5
17.5″
44
2″
5
6mm / 9.5mm72″
183
12″
30.5
19″
48
1″
2.5
6mm / 9.5mm84″
213
12″
30.5
19″
48
5″
13
7mm / 9.5mm84″
213
14″
35.5
20″
51
2.5″
6
7mm / 10mm84″
213
14″
35.5
21″
53
2″
5
7mm / 11mm96″
244
TBDTBDTBD
(Dimensions in inches and cm)

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:

  1. For single loop 2″ longer: 2×2=4″ more cord
  2. For single loop 3cm shorter: 2×3=6 cm less cord
  3. For double loops 3″ shorter: 4×3=12″ less cord
  4. For double loops 5cm longer: 5×4=20 cm more cord
Cord / Rope Total Cord LengthStanding EndWorking EndSingle Loop
Size
Double
Loop
Size
6mm / 8mm60″
152
26″
66
34″
86
10″
25
5″
13
7mm / 8mm72″
183
34″
86
38″
97
12″
30
6″
15
7mm / 9.5mm72″
183
32″
81
40″
102
12″
30
6″
15
8mm / 11mm84″
213
38″
97
46″
117
14″
36
7″
18
(Dimensions in inches and cm)

Note: When joining the two ends together after tying the friction hitch, 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. 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

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 / RopeTotal Cord LengthStanding EndWorking EndSingle Loop Size Double Loop Size
6mm / 8mm72″
183
36″
91
36″
91
9″
23
4″
10
6mm / 8mm
(compact)
60″
152
23″
58
37″
94
N/A0.5″
1
7mm / 8mm84″
213
45″
114
39″
99
12″
30
6″
15
7mm / 8mm
(compact)
64″
163
25″
64
39″
99
N/A0.75″
2
7mm / 9.5mm84″
213
42″
107
42″
107
11″
28
5″
13
7mm / 9.5mm (compact)72″
183
26″
66
46″
117
N/A0.5″
1
8mm / 11mm96″
244
50″
127
46″
117
14″
36
6.5″
17
8mm 11mm (compact)72″
183
26″
66
46″
117
N/A0.5″
1
(Dimensions in inches and 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 / RopeTotal Cord LengthStanding EndWorking End
6mm / 8mm60″
152 cm
15″
38 cm
45″
114 cm
7mm / 9.5 mm72″
183 cm
20″
51 cm
52″
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 DSRT

For DSRT, unless we have a very long adjustable bridge, we typically 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 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

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.