An important rule of bending is to, if possible, always make the bends closest to the center first and
work your way out. This allows you to make measurement corrections between bends. Based on this rule,
place a mark at the center of the rollbar tube. This is shown Figure 21.
BEND 1:
The first bend will be the
upper right side bend. Referring
to Figure 20, the upper dimension
of the rollbar is 50”. From the
center of the rollbar to the outside
of the bend is 25” (50” divided by
2). Lay the tubing to be bent on
the floor and hold the template
with the scribed side parallel
to the rollbar tubing and directly above it, as shown in Figure 21 . The scribed side of the template will
always face towards the center of the tubing being bent. Using a tape measure, slide the template left or
right until it is 25” from its outside edge, shown by the right arrow in Figure 21, to the rollbar’s center mark.
Using a marker, draw a small line on the rollbar directly below the scribed line. Take note of what side
of this mark the bend needs to be and draw an ‘X’ there so that when you load the tube into the bender
you’ll be bending on the correct side. Since the desired bend is only 70
o
and the template is 90
o
, you
will have to use your best judgement of when the template is 25” out. This gets easier with experience.
Now, load the tube into the bender and make the first bend. Don’t forget to over bend a little to account
for tube springback. For this material 3 to 4 degrees should be sufficient. Since all J D Squared benders
are equipped with degree of bend indicators this is easily accomplished. Once you know the correct over
bend required, you may want to record it for future reference.
BEND 2:
Place the template above
the rollbar tube with the template
line facing bend 1 as shown in
figure 22. Using a tape measure,
position it for the desired 50”
outside to outside of the two
top rollbar bends. DO NOT
use the tube’s center mark
as a reference and place the
template 25” left of center. The
reason for this is that if the first
bend was not made at the exact right spot to achieve 25” from center you can correct for the error in the
second bend’s position. Once again, since the bend will be 70
o
and the template is 90
o
you must use your
judgement as to where to position the template. Place a mark on the rollbar tube exactly underneath the
template line. Load the tube in the bender so that the bend will be made on the CORRECT side of the
tube and make the 70
o
bend.
Erase the center mark on the rollbar tube. Using the tape measure, place a new center mark exactly
midway between the outside of the two bends. Why? Let’s say your measurement shows the two top
bends are really 50 1/4” wide instead of the desired 50”. In that case, your old center mark could be off by
as much as a 1/4”. The NEW center mark corrects this error. That’s the cool part about template bending.
Your errors can generally be fixed with the next bend. Also note that if you had not started your bending
from the center of the rollbar you would not have been able to make the correction. Every bend adds a
little more error and you end up with a rollbar that does not fit.
25”
50”
Figure 21 - Template positioned for 1st bend.
Figure 22 - 2nd bend position
Tube’s
Center Mark
Template Line
Template Line
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