Propeller replacement

[Bengt J]

See this post with an updated Technical Committee decision effective 2 February 2024

Over the last few years several boats have lost propellers or one of the blades.

The Flexofold racing propellers that was standard on most US built boats are no longer in production, the classic blade from Flexofold will fit the racing hub if installed as a pair. The classic blades are class legal as a replacement.

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The bigger issue the Technical Committee considered was how to allow for replacement parts when standard equipment is no longer available, as has been done with winches, backstay adjusters, furling systems etc.

The TC reviewed J109 specifications and owner manuals over the years of production and found several propeller options, therefore the TC will allow replacement as follows:

Replace existing/damaged propeller with any brass/bronze 2-blade geared folding propeller no smaller than 16" diameter.

[carlbraden]

Hi Bengt J,
Are you please able to share with me what the exact Flexofold model you used as a replacement?
Thanks
Carl

[Vento Solare]

Carl,

I replaced my prop in 2017 when it inconveniently fell off. These are the parts that Flexofold shipped from Denmark.

• 16x13 LC bladeset
• SD2c composite hub M16x2 nut

[Bengt J]

Unfortunately that is not a Class Legal replacement. To the best of the TC knowledge two Newport boats replaced props with the composite hub without checking with the TC first.

Two class legal props are Flexofold (Racing or Classic) or Gori, all bronze props minimum 16" diameter. Currently I do not have part numbers for the different models.

[Vento Solare]

Bengt - it was what Flexofold had in stock when I needed a replacement air shipped in 2017 seven days before Block Island Race Week. I'll need a waiver for class racing for the future. I have to say the composite hub is identical in size and profile to the bronze hub and offers the advantage of electrical isolation of the blades. This results in better electrolysis and pitting characteristics. There is some weight difference but negligible when compared to the overall weight differenced in the hulls that have been measured. I know of no sailing performance improvement over the bronze hub.

My recommendation is the TC evaluate the Flexofold composite hub as an authorized replacement. In the mean time, consider this a request for a waiver so that Vento Solare may race with this prop for all future events.

[carlbraden]

Thanks guys - very helpful - I will reach out to Flexofold
Carl

[Vento Solare]

Good luck Carl. I just went to the Flexofold site to get further information for the Technical Committee. They were acquired by Yanmar but still maintain their autonomy.

For the TC - The composite hub is dimensionally the same and weighs 2.8 Kg (6.17 lbs) less than the bronze hub. Links below for the specs.

• Flexofold 2 Blade Folding Propeller (Bronze Hub)
• Flexofold 2 Blade Folding Propeller (Bronze Hub with Large Anode)
• Flexofold 2 Blade Folding Propeller (Composite hub)

[Vento Solare]

This is an update for 2024. The technical committee has been tasked to provide a review of the Flexofold composite hub used as a replacement for the bronze hub. Once the review is complete, the results will be posted here.

[Vento Solare]

This is an update by the Technical Committee effective 2 February 2024

Propeller Replacement

Background: The Technical Committee has reviewed requests related to replacement of the Flexofold Two Blade folding propeller (16" diameter) that was installed as original equipment on most US built boats. The factory installed equipment consisted of a bronze hub and two bronze “racing” blades. The original configuration with the exact blade shape and bronze hub is no longer available. Similar Flexofold Two Blade folding propellers are available with different blade shapes and different hubs. The current products available include the Large Anode (LA) Bronze Hub version, Standard Bronze Hub version and a Composite Hub version. The Composite Hub is currently the only available hub that is compatible with the racing blades originally installed on the boat. The original blades may be interchanged with the new style blades in pairs but may not be mixed.

Decision: Based on the unavailability of the original equipment, the Technical Committee has determined that any of the currently available Flexofold Two Blade folding propellers and blades systems may be used as a direct replacement for the original equipment. Additionally based on the previous review by the Technical Committee the Gori 2 Blade Sail Drive and Gori 2 Blade Racing Sail Drive 16 inch bronze propellers are authorized.