J/70 Rake Run 101

Mario Trindade from Quantum Sails Mallorca checks in with what you need to know about the latest trends in mast rake on the J/70. While technical, dialing in these finer details can take your tune and trim to the next level. As always, please reach out to Mario or our other J/70 class experts with any questions. Access the Quantum J/70 tuning and trim guides on our website.

As a follower and competitor in the J/70 class for many years, a clear trend I’ve observed is dropping the rig with longer and longer rakes. The “rake run” (54.5” in 2017 to 59/60ish” in 2023) aims to move the center of effort of the sail plan aft, delivering more rudder angle and some “feel” to a usually weightless drive when going upwind. 

The trend is good but needs to be executed carefully — it’s not as simple as dropping the rig and still setting for the same tensions as before, as some people think. Increasing the rake a lot, like we are doing, generates a change in geometry that brings different bend behaviors to the rig — remember, the chainplates are still in the same position. That means when testing new rake numbers, make sure that the dock tune prebend of your base is matched. Otherwise, you might end up needing to play with the vertical and diagonal shrouds to get the designed luff curve of the sails. Each time, make note of tuning changes so you can replicate the setup in the future. 

Other consequences of the longer rake are not only the obvious change in the jib lead, but also a change in how you’ll sail downwind. Once again, we have the same kite luff lengths as the original set-up, but now we have the rake six inches longer. This will change the kite's behavior dramatically in all modes. The tighter luff of the sail will flatten the entry on the displacement and lazy plane modes, affecting projection. On the other hand, it will close the kite’s “leech” when sailing wing-on-wing. 

As with everything in life, “There ain’t no such thing as free lunch!” Everything is a compromise. The optimum rake number is the one that delivers a good performance balance for both upwind and downwind. So, the biggest question heading into this season is…what is your number? 

About Mario Trindade, Sail Designer, Quantum Sails Mallorca

Born and raised in Rio de Janeiro, Brazil, in a sailing family, Trindade’s professional sailing career took him around the globe to compete in multiple Grand Prix and One Design Classes, winning the 2019 J/70 World Championship, 2021 SB20 World Championship, and numerous South American and National championships. After more than a decade of professional racing, he earned a degree in Yacht Design from Solent University in the United Kingdom, developing his skills and advancing to the next level of Grand Prix sailing and technology development. Still racing on the TP52 circuit today, Trindade combines his on-water knowledge, technical experience and attention to detail to provide the best experience for Quantum customers, using tools like Quantum’s IQ technology to ensure superior performance. 

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