I have built the Kingfisher designed by Graham King and a cedar strip racing single shell.  The Kingfisher (plans available from Wooden Boat Mag or several past issues of WB on building the Kingfisher would give one an idea of the bracing needed to use exterior riggers.  Also, you could build a platform for seat slides and assembly.  Get a book on rigging, like one from Mike Davenport.  This would give the dimensions for riggers.  They could be a coupe of two by fours as long as they put the oarlock the correct distance outboard and "though the pin" and height above the seat (or waterline).  Davenport ( I think it is " The nuts and bolt of rigging") also covers where the fot stretchers go .  I think you could save much weight over the drop in units ( and cash), with some homework.  Check out Concept II for the oarlocks.  Best luck, Rich Prager.

I've thought about this, too. The Piantedosi rig weighs 18 pounds (I've weighed it). You can add a new lightweight seat (http://www.grahamseats.com/) and keep the unit.

Or, you could add a wing rigger (WinTech) to your boat, or buy just the drop-in arms and oarlocks from Alden (who sells Piantedosi riggers now). You could then buy tracks and the seat assembly from Latanzo. You'll have to build a support for the tracks. That, and the tracks and seat assembly, will weigh something!

At best you'll only save a few pounds and you'll double or triple your labor, and you'll need to engineer the rigging dimensions as Rich Prager noted. I don't know if saving a few pounds will affect that boat's performance significantly. One builder used lighter plywood - look on duckworks for the article.

My thought was to use a hole saw to cut some 1-1 1/2" holes to lighten the Piantedosi monorail somewhat. That's where most of the weight of the drop-in unit is concentrated. I thought I'd take a tip from the old-time cyclists during the "drillium" era.

Best,

Tony

Hey Rich - what cedar strip shell did you build? I bought plans for the Dragonfly, designed by Steve Killing but haven't done anything yet. Also, did you build the Kingfisher straight from the plans, or from a kit? I was thinking about this boat, too, and I contacted Graeme King a few months ago. He still had one or two kits, he said.

Thanks,

Tony

Drillium approach to lightening the Piantidosi unit is a good idea.  Also, since it is made long enough for the tallest rower, most of us can shorten it for further weight saving.  Me especially, at just 5'4" ;-)