Custom CanvasCustom CushionsCustom Rigging by JSICustom Spars by JSISails - Get Free Quote Online Now!Clothing @ Island NauticalBoating Hardware @ Island NauticalJSI, The Sailing Source
 

Home      Contact      Links       Wish List      Policies      Checkout 

 Shopping Cart:
 0 Items In Cart
 Total: $0.00
 
Checkout
 

Bimini Top Design & Measurement Guide

There are three basic mounting methods for bimini tops:
 
Split Mount Single Mount Dog Leg
 
These different mounting methods for bimini tops vary enough to accommodate most sailboats.
 
To select the proper mounting arrangement, you must know where the center of the length of the top is.
You will need a tape measure, pencil, sheet of paper and follow the diagram and these easy steps
to obtain the necessary measurements for us to build you a bimini top. It's that simple!

Step 1: Hoist the mainsail and sheet it in to the centerline of the boat for the lowest position of the
boom. Make sure the gooseneck and down haul are set properly, and that the topping lift is adjusted to accommodate the set of the mainsail.
 
Step 2: Measure the height from the cockpit sole to the bottom of the boom, or boom bales whichever is lower. Subtract 2 inches.
NOTE: On all these measurements, allow at least 2 inches of clearance so the bimini will not chafe against the mainsheet, backstay, or the boom.
 
Step 3: Measure from the backstay to the mainsheet at the final height in Step 2.
Subtract 4 inches. If the mainsheet attaches to the end of the boom, the top may have to be either forward or aft of the mainsheet.  
 
Step 4: Calculate and mark the halfway point of the length on the coaming.
This can be done by laying one tape measure fore and aft, and another tape measure athwartship at the center of the halfway point.
 
Step 5: Check for rotation clearance on the winch handle, with it in the winch and your hand gripping the handle. To do this, hold the tape on the coaming center mark (from Step 4) and angle aft or forward over the top of the winch handle to the area where the top would end at the height (from Step 2) fore and aft.
    (A) If you have winch handle clearance, go to Step 6.
    (B) If you don't have winch handle clearance, proceed with one of the following:
          1. From the center mark on the coaming (from Step 4) measure past the winch until you gain enough winch handle clearance and put a mark. Measure the same distance in the opposite direction and put another mark. These would be mounting positions for fore and aft deck mounts. Measure the distance (“split”) between the fore and aft mounting positions and make note.

OR

           2. The “Dog Leg” mount. This type of mounting is used when the single mount (center mounting) is too low or there isn't enough room to allow for a split mount. The actual mounting position is 4 to 8 inches off the centerline depending on the height of the top. (The radius in the dog leg bend changes from boat to boat in order to accommodate winches and winch handle clearance.) The lower the top is from 45 inches high, the more
the mount moves off center. This should be noted for the direction of the dog leg bend. This arrangement must be well considered for folding the top down. The outside radius of the bend in the frame should face aft if the top is to fold forward and vice versa.
 
Step 6: Measure athwartship for mounting width. If you come up with a “split” mount in Step 5 try to keep the width the same fore and aft even if one side mounts inboard and the other mounts outboard on the coaming.
On center cockpit boats it is encouraged to use a split mount, especially if you have a walk through. In this case, the forward mount should be just forward of the walk through and as far outboard as possible to maintain the maximum desired width and ease of entry/exit. On center cockpit boats without a walk through, a single mount top is satisfactory but should be discouraged if you plan to add an enclosure at a later date. The “split” would double as a doorway, thus making entry/exit much easier regardless of which side of a dock you tie up to.
 
Step 7: Actual Height:
    (A) Single Mount or Dog Leg Mount - Take the height from the sole to the boom, less 2 inches, and subtract the distance from the sole to the top of the cockpit seat and the distance from the seat to the coaming at the level of the deck mount.
    (B) Split Mount - Same as Step 7 A, but take measurements at the forward and aft mounts, because the coaming may have a rise which will make one set of frames taller than the other.
 
FINAL NOTE: The projection of overhang in relation to the deck mount to the aft end of the top and from the deck mount to the forward end of the top should be the same, or as close as possible.
 
Example 1: Single Mount Top - 80 inches long. Deck mount in center with 40 inches aft of the mount and 40 inches forward of the mount. If not the same, take measurement from center point of bimini to forward deck mount and from center point of bimini to aft deck mount.
 
Example 2: Split Mount Top - 80 inches long, with a 24 inches split. Overhang of 28 inches aft of the aft mount, with a 24 inches split and a overhang of 28 inches forward of the forward mount.
 
NOTICE 1: Please take special note of the strap lengths and include them with your bimini top measurements. The measurement is taken 3 inches inboard from each leg bend on the frames to a point approximately 12 inches forward of the forward end of the bimini, and aft of the aft end of the bimini. You may have to angle the straps inboard several inches to get around any deck hardware.
NOTICE 2: If you desire a bimini, which has a single or split backstay through the canvas, use the following: (schematic)
1. Follow Step 2 (on page 1) to determine the height of the bimini from the sole.
Mark with masking tape on the backstay at this height. If you have a split backstay, mark both pieces.
The measurements we need to locate the backstays are:
   (A) The distance from tape to tape, and
   (B)The centerline distance from the stern pulpit to a line plumb from the tape
(providing the   stern pulpit is where you want the top to end).
 2. For the overall length on aft cockpit boats, follow Step 3 (on page 1),
but measure from the stern pulpit instead of the backstay. Subtract 2 inches from the forward end instead of 4 inches overall.
 
Fill in the form below with your preference of stainless steel or aluminum frames and your choice of fabric. 
 
 (Please make sure the unit of measurement is in inches!)
 
SINGLE MOUNT: Length:____________  Height:_________ Width:_________________
DOUBLE MOUNT:  Length:_________ Width (Fwd):______ Width (Aft):______________
Height (Fwd):______________Height (Aft):____________ Split (Aft):__________________
FABRIC: Sunbrella®:___________________________________ Color:______________________________
Sunbrella® Color Choices: Black, Royal Blue, Pacific Blue, Navy, White, Grey or Forest Green 
Type of Frame:    ____________1" Stainless Steel    ____________7/8" Aluminum 
 
PERSONAL INFORMATION:
Name:_______________________________________________________________________________
Address:_____________________________________________________________________________ 
City:______________________________________________ 
State:____________ Zip:________________ Type of   Boat:_________________________
email:___________________________________ Home Phone:_______________________
Work Phone:_______________________________   
 

 

TOC

 

  Search: Search  



SecurityMetrics for PCI Compliance, QSA, IDS, Penetration Testing, Forensics, and Vulnerability Assessment
 
Sign up for our Weekly Email Specials
Email: