FlexoFold Prop Size Identification/Confirmation

[Stu Jackson]

As you may imagine, this prop has been discussed on this forum for many years.  I suggest you search on read previous posts about pitch and diameter before you make a purchase or set one up.  Many of our skippers have "been there, done that" so you can avoid reinventing the wheel.  Good luck.

Mike,

Please, do a search on this board, as I suggested.  Why?  Because the skippers who have BTDT may simply not be reading this forum (today, this week, this month, maybe sold their boats but did know what worked...).  There's 13 years of material and knowledge on this board.  Type in the search box and read away.

Good luck.

[Clay Greene]

Noah, my point was only that you can't compare props on different engines and transmissions.  I don't have any basis to speak to the right two-blade prop on a M25XP - we had a 15 x 9 three-blade on our boat with that engine and it worked well for us.  I know that Flexofold recommended to us in 2010 to go with a 15 x 9 three-blade or a 15 x 10 on a two-blade.  As is usually the case, Stu is exactly right that real-world experience from other owners with that engine, transmission and prop is the best guide of whether it is the right prop or not. 

[Mike McDonald]

I wanted to follow up with Stu and Clay. I had done the search for past FlexOFold discussions, and I believe I read them all. Still some uncertainty with constantly changing recommendations.
Clay,
You indicated in your response that you had a 15x9, 3-blade FOF prop. I found one of your earlier posts indicating that you had a 15x10? For reference I'll try to copy your previous post below. Here goes.

.......................................................
claygr:
Want to report on our first experiences with the Flexofold prop.  We went with the three-blade, 10 inch pitch.  The recommendation from the Flexofold representative was for the 9 inch pitch based on our engine (M25XP).  However, based on the input from other owners on the site and the fact that our old prop was 10 pitch, we went for the 15 x 10. 

Installation of the new prop was very easy.  As promised by the sales representative, the hardest part was getting the old prop off.  That required quite a bit of effort with a puller.  Once the old prop was off, the new prop went on in about 20 minutes. 

The performance under both power and sail is pretty amazing.  Under power, we are at least a half knot faster in forward.  We can get up to 3000 RPMs with no problem with black smoke or temperature issues.  At top end, we're burying the stern in the water and reaching close to hull speed. 

The performance in reverse is also very impressive.  I can now back in a straight line in relatively low RPMs.  I previously would only go sideways until I got a good bit of speed up.  It has taken some adjustment, though, because I previously had to steer to starboard to reverse in a relatively straight line out of the slip and now that actually causes the boat to turn to starboard, a completely new phenomenom for me.  Imagine that - the boat actually going where you steer in reverse. 

It also has taken a bit of adjustment while docking.  I previously could count on the drag of the prop to slow the boat in neutral.  She just is not slowing the way she used to anymore.  I've had to start using more reverse earlier on in so I don't scare the neighbors.  Not a problem, just an adjustment. 

The performance under sail is exceptional.  We were hitting 7.2-7.4 on the GPS in 18 knots apparent from a beam reach.  Never seen that before.  The sound of water rushing by at the stern was very loud. 

So, not to sound too much like a Flexofold salesman, I am very happy with this purchase.  This is by far and away the best boat purchase I have made in terms of improving performance under way, and that includes the sails I have replaced and the asymmetrical spinnaker I purchased.  Also, if you are interested in this, remember that Flexofold gives a "boat show" discount to C34IA members so that is yet another reason that the membership more than pays for itself.

........................................

It sounds you were very happy with the prop you installed, maybe I missed something, or one was a typo??

Can you clarify. Thanks.
Mike.....

[Clay Greene]

Hmmm......

Well, I can say for sure that Flexofold recommended a 15 x9 prop because I went back and checked the e-mail discussions with the representative.  I can also say for sure that we were very pleased with the performance.  I don't have any e-mails with Flexofold indicating we were going up a size in pitch but the post you copied is probably right because it is close in time to when we purchased and installed the prop.  So, I guess you can put me in the camp of happy 15 x 10 three-blade owners.  Sorry for any confusion caused by my faulty memory. 

[Mike McDonald]

Thanks for the follow up Clay.  No problem.  If I had to rely on my memory for these things I'd be in big trouble.  Thank God for post it notes and phone calendars!  Just trying to sort it all out. Thanks again.
Mike....

[Ed Shankle]

Mike,
I've got a Flex o Fold 15x10. M25XP engine. They originally recommended 15x9, but when I said my existing fixed 3 blade was 15x10, they said, then the 15x10 folder would probably be ok. No issues with it; got increased speed under power as well as the expected under sail. Yes, stopping isn't the same, but a fair trade off in my mind.

Ed

[Mike McDonald]

Ed,
Thanks for the follow up. I've been out of touch for the last week or so. Glad to hear that another owner is happy with this size FlexOFold prop.
Mike...