10
To find out the cutting length of the top extrusion (D) and the length of the top distance
tube (E), start with the length of the forestay wire (WL) that was calculated in table 1. Then
follow the steps in table 2 below. On fixed length forestays (incl. rod stays), verify WL by
measuring the stay length from centre of eye to end of stud (wire) or end of rod head.
Note: The length of the top distance tube (E) is deliberate designed with some centimeters
vertical space of the distance tubes and joining sleeves in the total length of luff extrusion.
You can also use the FURLEX CALCULATOR on our web site. Go directly to the calculator by scanning the
QR-code with your mobile device.
Table 2: Calculation of top luff extrusion length and top distance tube length
Your forestay
Example
(204S/Ø8)
with rigging screw
50% extended
WL
Length of the new forestay wire (as per Table 1).
16068
A+B
1270
N
Number of full length extrusions to be used:
N = ( WL - (A+B) ) / 2400 (94 1/2”)
(16068-1270)
/2400=6.16
N=6
C
Total length of the number of full length extrusions (2400 mm) to be used:
C = N x 2400 (94 1/2”)
6 x 2400 =
14400
D*
Length of top luff extrusion:
D = WL – (A+B) – C
16068-1270
-14400 = 398
X
Fixed deduction
204S: 200 mm (7 7/8”)
304S: 250 mm (9 27/32”)
200
E*
Length of the top distance tube:
E=D-X
398-200 =
198
WIRE
Without rigging screw:
With rigging screw:
204S
Ø6 mm wire: 1295 mm (50 63/64”)
Ø7 mm wire: 1320 mm (51 31/32”)
Ø8 mm wire: 1335 mm (52 9/16”)
Ø6 mm wire: 1250 mm (49 7/32”)
Ø7 mm wire: 1250 mm (49 7/32”)
Ø8 mm wire: 1270 mm (50”)
304S
Ø8 mm wire: 1370 mm (53 15/16”)
Ø10 mm wire: 1405 mm (55 5/16”)
Ø8 mm wire: 1290 mm (50 25/32”)
Ø10 mm wire: 1315 mm (51 49/64”)
*) If, as in our example, D becomes less than 400 mm it is necessary to recalculate as below and cut one of the
full length luff extrusions
according to D
new
and one of the
full length distance tubes
according to E
new
.
Note that the original top luff extrusion and the original top distance tube will now be used as intermediate
extrusions.
Table 2B: Recalculation if D<400 mm
Your forestay
Example
N
new
Reduce the number of full length extrusions by one.
N
new
= N-1
N=5
C
new
C
new
= N
new
x 2400 + 2000 (94 1/2” + 78 47/64”)
14000
D
new
D
new
= D + 400 (15 3/4”)
798
E
new
E
new
= E + 400 (15 3/4”)
598
ROD
Without rigging screw:
With rigging screw:
204S
Rod -8: 1255 mm (49 13/32”)
Rod -10: 1280 mm (50 25/64”)
Rod -12: 1285 mm (50 19/32”)
Rod -15: 1285 mm (50 19/32”)
Rod -8: 1210 mm (47 41/64”)
Rod -10: 1210 mm (47 41/64”)
Rod -12: 1220 mm (48 1/32”)
Rod -15: 1220 mm (48 1/32”)
304S
Rod -15: 1320 mm (51 31/32”)
Rod -17: 1355 mm (53 11/32”)
Rod -22: 1415 mm (55 45/64”)
Rod -15: 1240 mm (48 13/16”)
Rod -17: 1265 mm (49 51/64”)
Rod -22: 1325 mm (52 11/64”)
