For those running non piped engines that are bemoaning the demise of Bolly and the retirement of Brian Eather, I found that one of the Mejlik props sold by Randy Smith gives very good results on my DS-60.  Its the 12.5x5.2 three blade, and on the 60 its the best three blade carbon I have tried to date.  I'm guessing it will be a good prop for ST 60s and four strokes as well.
When I tried a depitched Bolly 12x6.5 3 blade, it never seemed the motor could see any load until I had the pitch over 5.75 or more, at which point the windup was rather poor.  The undercamber Mejlik with its greater diameter loads the engine exactly the same as the 12.75 x5.9 wood I was using, and I launch at the same exact RPM.  I like the prop, and its going to stay on the airplane for awhile...

My Enya 61CXS Pro likes this prop too. Mejzlik web site says it is designed for non-piped 60's.

We are thinking of buying a couple of those props since we only have 4 bolly props, and one is on a plane allready.  Now undercamber creates a greater load on the motor, right?

Yes these are a slight undercamber  and  they have more load from the UC

Randy

Whatcha got for unpiped .75/.76's, Randy?  Steve

New 13 x 4.7 3 blades in stock, and  coming  new 14.5 x 5.5 wide 2 blade

Randy