J/70 running rigging
All classesEvery line on the boat: what the class rules, builders, riggers and rope makers name for it, and the rope we stock for each. We show what the sources say and add no tuning advice of our own. Sizes are rope diameters.
- lines
- 19lines
- stocked
- 17stocked
- with an exact match
- 12with an exact match
- sources
- 10sources
Exact the rope the source namesAnalogue same fibre, heat-set, cover, sizeNearest closest we stock, differing attribute namedNot stocked not in our range
Halyards 6 lines
Main halyard
Class rule: min 6 mm1Common ground
Dyneema SK78 core, polyester cover · 6 mm
Typical: Spliced eye or shackle at the sail end, whipped tail. We splice to order.
What each source names (3)· sources differ, shown side by side
Main halyard tail & fine-tuneoptional
Class rule: tail min 4 mm · fine-tune min 6 mm1Common ground
No product named by any source
Typical: Fine-tune runs through a loop spliced in the working part. We splice to order.
No source names a rope for this line — only the class minimum above. Browse ropes by diameter in the rope list.
Jib halyard
Class rule: min 4 mm1Common ground
Single-braid Dyneema SK78 · 4–6 mm
Typical: Eye splice at both ends, soft loop shackle at the sail. We splice to order.
What each source names (3)· sources differ, shown side by side
- J/Boats owner guide2Names: Marlow Excel D12 4 mm
Jib halyard hoisting tail
Class rule: no minimum listed for this lineCommon ground
5 mm · fibre differs between sources
Typical: Spliced to the halyard. We splice to order.
What each source names (3)· sources differ, shown side by side
- J/Boats owner guide2Names: Marlow control line 5 mmNot in our range — we don’t stock this rope or a close match.Not stocked
Jib halyard fine-tune
Class rule: min 6 mm1Common ground
6 mm · polyester pre-stretch or Dyneema-core line
Typical: Whipped ends. We splice to order.
What each source names (2)· sources differ, shown side by side
Gennaker halyard
Class rule: min 6 mm1Common ground
6 mm · SK78-core or polyester pre-stretch
Typical: Splice-on shackle with stopper ball at the head, whipped tail. We splice to order.
What each source names (5)· sources differ, shown side by side
Sheets 3 lines
Mainsheet
Class rule: min 8 mm1Common ground
Dyneema-based braid · 8 mm
Typical: Eye splice at the dead end, whipped at the other. We splice to order.
What each source names (5)· sources differ, shown side by side
Jib sheet
Class rule: min 8 mm1Common ground
8 mm · products differ
Typical: Whipped ends; tapered ends possible. We splice to order.
What each source names (4)· sources differ, shown side by side
Gennaker sheet
Class rule: min 6 mm1Common ground
Dyneema-core double braid · 6–8 mm
Typical: Tapered ends with small eye splices. We splice to order.
What each source names (5)· sources differ, shown side by side
- J/Boats owner guide2Names: Marlow Excel Fusion 7 mmNot in our range — we don’t stock this rope or a close match.Not stocked
- West Coast Sailing4Names: D2 Race / Endura BraidNot in our range — we don’t stock this rope or a close match.Not stocked
- Robline catalogue9Names: Robline Coppa Dura 7 mm
- Gleistein10Names: Gleistein RunnerTwin Equipe 8 mm
Control lines 7 lines
Traveller control
Class rule: min 6 mm1Common ground
5 mm in the rig lists · 6 mm in the 2026 class rule
Sources disagree on size: the 2026 class rule says at least 6 mm; J/Boats, Upffront and West Coast Sailing list 5 mm.
Typical: Whipped ends. We splice to order.
What each source names (3)· sources differ, shown side by side
Vang control line
Class rule: min 6 mm1Common ground
6–6.5 mm
Typical: Whipped ends. We splice to order.
What each source names (4)· sources differ, shown side by side
- J/Boats owner guide2Names: Marlow 8-plait Prestretch 6 mm
Cunningham
Class rule: no class minimumCommon ground
3 mm Dyneema line with a 6 mm purchase line (one source)
Typical: Soft eyes on the Dyneema line, whipped purchase line. We splice to order.
What each source names (2)
No source names a rope for this line — only the class minimum above. Browse ropes by diameter in the rope list.
Backstay control
Class rule: min 6 mm1Common ground
6 mm · polyester or SK78-core control line
Typical: Whipped ends; Dyneema single-braid strop in the purchase. We splice to order.
What each source names (4)· sources differ, shown side by side
Gennaker tack line
Class rule: min 7 mm1Common ground
Dyneema-based · 6–8 mm
Sources disagree on size: the 2026 class rule says at least 7 mm; the 2012 J/Boats list gives 6 mm.
Typical: Eye splice with soft loop shackle at the tack, ball at the pole end. We splice to order.
What each source names (2)· sources differ, shown side by side
Strops & backstay 3 lines
Mainsheet strop
Class rule: min 5 mm1Common ground
Dyneema single braid · 5 mm (one source)
Typical: Soft eyes at both ends. We splice to order.
Vang strop
Class rule: min 5 mm1Common ground
Dyneema single braid · 5 mm
Typical: Soft eyes at both ends. We splice to order.
What each source names (2)· sources differ, shown side by side
- J/Boats owner guide2Names: Marlow Excel D12 5 mm
Backstay upper leg
Class rule: min 5 mm, low-stretch composite1Common ground
Low-stretch composite (e.g. Dyneema) · one source names 6 mm SK99 core
Typical: Soft eye splice with lashed thimble at the lower end. We splice to order.
What each source names (1)
Notes on our data
- Gottifredi Maffioli Superswift: our catalogue sheet lists it as single braid, but its product facts name a core (Compact 78) and a cover, so this guide treats it as double braid, as the product page does.
Sources
- International J/70 Class Rules, effective 01 Feb 2026 (F.4.1 running rigging minimum diameters; C.9.1(d) any type of line allowed). https://j70ica.org/wp-content/uploads/2026/02/J70-Class-Rules-2026-1.pdf Seen 2026-10-23.
- J/Boats J/70 Owner Guide (2012), Appendix B: Marlow Running Rigging Specifications (original factory running rigging as of 5/14/12). https://www.ksss.se/contentassets/e3880590f04f42938e4d80310310db00/j70-user-manual.pdf Seen 2026-10-23.
- Marlow Excel Racing construction (SK78 core, PU coated, 16-plait polyester cover) as stated by retailers, not by Marlow: Jimmy Green; Sheridan Marine. https://jimmygreen.com/marlow-excel-racing-halyards/77614-marlow-excel-racing-6mm Seen 2026-10-23.
- West Coast Sailing (US rig shop), J/70 Line & Running Rigging pages (kit descriptions; no publication year). https://westcoastsailing.net/parts/j-70-sailboat-parts Seen 2026-10-23.
- West Coast Sailing, J/70 Main Halyard w/ Shackle (Excel Racing) and J/70 Jib Halyard Amsteel product pages. https://westcoastsailing.net/j70-main-halyard-w-shackle-j70101 Seen 2026-10-23.
- Diego Sosa (Upffront), "J/70 Running Rigging", Yachts and Yachting, 19 Sep 2018 - based on Gottifredi Maffioli range. https://www.yachtsandyachting.com/news/210075/J-70-Running-Rigging Seen 2026-10-23.
- Upffront.com, "J70 Running Rigging", blog, 7 Jun 2024 - same recommendations as 2018, based on Gottifredi Maffioli range. https://www.upffront.com/blog/sailing-equipment-1/j70-running-rigging-35 Seen 2026-10-23.
- yacht.de (Hauke Schmidt), "Class-compliant tuning for the J/70", 18 Apr 2019 - Frisch/Harken package with Robline Dinghy Star. https://www.yacht.de/en/fittings/deck-fittings-class-compliant-tuning-for-the-j-70/ Seen 2026-10-23.
- Robline catalogue "Yachting Ropes and Kite Lines" 2025-2026, pp.19-21 (Dinghy Star, Coppa Dura, 0-Kink; intended-use lines). (maker’s PDF catalogue; not linked online) Seen 2026-10-23.
- Gleistein RunnerTwin Equipe product page (Lindemann KG): "specially developed for small, fast keel yachts such as J/70 and Melges 24". https://www.lindemann-kg.de/en/products/1/Gleistein%20-%20Schoten%20und%20Fallen/RunnerTwin%20Equipe Seen 2026-10-23.
- Sailmaker tuning guides checked, no rope specification in them: Quantum, Doyle 2024, North 2021 (Ullman PDF not readable: HTTP 401). https://www.doylesails.com/wp-content/uploads/2023/11/J70-Tuning-Guide-2024.pdf Seen 2026-10-23.
Prices per metre incl. 24% VAT, live from our rope list.