We are asked from time to time by prospective new customers just what our drive units are like and what is meant by the term “Quadritwist”.

As far as what our drive units are like, the first impression on seeing one in a Nauticraft boat is that it “belongs there”.  This visual impression comes from the drive unit housing being made from the same material as the boat – a white plastic with black specks (we had the black specks incorporated into the material a few years ago).

On our original drive unit (which we now also call our “inboard unit”) the driving belt twists four times going through its path, from the pedaling sprocket to the driven sprocket, over the idlers, and then back around to the start – hence the term “Quadritwist”.  We have a very positive regard for this system because it gives us the required directional change as well as the required speed increase (a 1:4 increase) with no energy robbing torsional or axial side effects; with this type of layout the twists of the belt are actually “natural” ones.

Looking further at the drive unit it is obvious that the pedal cranks come from the bicycle industry, and this is so, as we purchase these cranks as well as its axle assembly (known in the industry by the unlikely term “bottom bracket”) from a bicycle parts supply house.  The pedals also come from there and, because they are often used that way, are of the “barefoot” type (some sophisticated customers, familiar with upscale bicycling, sometimes change these pedals for their own particular choice).

An even closer inspection of the drive unit shows that the mechanical aspects (all of the moving parts) are located on the outside of the drive housing.  Our drive unit is designed this way because the mechanical parts (particularly the belt and sprockets – being of plastic materials) do not need oil or grease lubrication as do metal parts (the plastic materials also are not susceptible to water corrosion as are metals).  Also, because all mechanical assemblies need care and maintenance from time to time, it is far easier to service an assembly that is out in the open.  For instance, although it will serve for a long time, the drive belt can be changed for a new one without removing the drive unit from the boat – and without requiring any tools.

We designed this system ourselves (using the quadritwist philosophy originally proposed to us by Phil Thiel, a marine engineer from Seattle) and have been happily using it in our boats for over 15 years now, with only incidental changes.  We manufacture it right here in our own shop – from rotational molding the housing through all of the subsequent assembly steps.

Next time I’ll talk about the “swing down” drive unit used in our Sprite model – why it doesn’t use the quadritwist system, but how it is similar to it as well as how it is different.

Printable View

I bought my Escapade in the spring of 2001 as a 50^th birthday present to myself. I named my pedal boat RiverSong, and now—as my 12^th boating season begins—I still love it as much as ever.

I lease a slip near the Pentagon from April through October and pedal the Potomac within view of the Washington Monument and Lincoln and Jefferson Memorials. I usually take my first ride of the year while the cherry trees are still in bloom and my last as flocks of geese are migrating south overhead. Sometimes I pedal past the Kennedy Center and ride as far as Georgetown.

Because I have a demanding job in DC, I don’t get out on the river every day, but I try to take at least one evening ride and one weekend ride each week. People are always commenting on my boat, and tourists ask where they can rent one.  The cleverest remark from a passerby was: “Oh, a two-stroke engine!”

Like most boaters, I appreciate the beauty of the water and sky at least as much as what’s on shore. The scenery is perpetually changing, as is the play of sunlight on water. Occasionally I have trailered my boat to state parks and enjoyed pedaling on gorgeous lakes. As my husband Don likes to say, “The purpose of a boat is to take all the water up there… and put it back there.”

Sometimes Don comes along for a ride, but usually our dog is my only passenger. Our cairn terrier Boscoe accompanied me to Michigan when I bought the boat to give it his “paw of approval.” Boscoe passed away six years ago, but our young dog Skruffy enjoys boating even more than Boscoe did. He thinks we own the Potomac.  

Trish

Alexandria, VA

We get a variety of questions when folks call inquiring about the boats and often it’s to ask if it is big enough to fit a pet.  I say pet because, although it is mostly dogs, we do have a few folks ask about other 4 legged friends as well.  In this month’s narrative, read Curt’s version of “Chelsea’s Pedal Boat Adventure” from Summer 2011.

Relating to the Christmas gifts which are being offered, customers ask if they need a Storage Cradle to store the boats on while out of the water.  The Storage Cradle was designed specifically for the Escapade pedal boat to accommodate the deep narrow keel of the boat.  The Escapade can’t sit on its keel as many flat bottom boats do, so when taken out of the water it lays on its side which may over time affect the shape of the hull.  The storage cradle is designed to fit the keel and also to hold the “belly” of the boat while keeping the boat upright.  It is also very useful during shipping, as supports are needed to keep the boat upright during the shipping process.  The Encore models do not need any sort of a storage cradle as it will set on the double keels and the bow of the boat without issues.

One thing about using a storage cradle is the challenge of getting the boat onto it.  The Escapade weights about 325 lbs, and is awkward to lift even with 4 people doing so.   Using a pulley system is a good bet when lifting the boat up onto the cradle.  For more specific instructions or for questions you may have contact Nauticraft directly at the factory.

http://www.ecofriend.com/entry/amazing-pedal-powered-boats/

• ENCORE
  • Raise the bow end of the boat; set it on a large block of Styrofoam (12″ x 12″ x 12″)which is placed somewhere between the bow and the front compartment.  This will allow water within the channels and the drive shafts to run out.
  •  Remove the drain plugs to allow any water which may have accumulated within the hull to drain out.  There shouldn’t be much, if any.  MAKE SURE TO REPLACE THE DRAIN PLUGS AFTER THIS PROCESS!
  • Remove the battery if it has one.  Store it in a garage or something like it, off of the concrete.  You can put it on a trickle charger periodically during the cold season to protect it from becoming too depleted.

  Contact Nauticraft by email or phone at (888) 709-7097 with any specific questions you may have concerning this subject.

Go to Michigan.org to see all the great things going on in Michigan this summer!  And then take a look at Nauticraft Boats!