2020 Ronstan Sailboat Hardware Catalogue - Page 133

FEATURES & INFORMATION
Curved Track Data
131
TRACK BENDING
In certain applications it is advantageous to curve tracks either horizontally (‘A’ bend) or
vertically (‘B’ bend). Track can be bent to match deck camber, or to ensure that the tension on a
purchase system attached to a traveller car remains constant as the car moves along the track.
HORIZONTAL PLANE – ‘A’ BEND
In situations where cars and fittings are required to rotate around a central pivot point,
horizontal ‘A’ bending of the track will ensure the load applied to the car remains vertical. This
results in maximum strength and free rolling ability being maintained by the car. Maintaining
this vertical alignment also ensures tension in an attached purchase system remains constant,
a feature often sought after in sailboat mainsheet and boom vang traveller systems.
‘A’ Bend
(Plan View)
VERTICAL PLANE – ‘B’ BEND
Traveller tracks can be bent vertically to fulfil certain requirements. They can be top mounted
or underhung mounted with either concave or convex track bends.
‘B’ bends are often required to match the mounting surface to which a track is to be fixed;
as when matching deck camber on a sailboat.
‘B’ bending can also be used to maintain constant tension in a purchase system mounted
on a traveller car. This application is very popular on sailboat mainsheet and self-tacking jib
systems where the increased load applied to the car during tacking or gybing may affect
sail trim or increase rolling friction.
MINIMUM BEND RADIUS
TRAVELLER
SERIES
CAR
LENGTH
mm
MINIMUM
HORIZONTAL
MINIMUM
'A' BEND
HORIZONTAL 'B'
RADIUS
BEND RADIUS
mm
mm
CAR
LENGTH
in
MINIMUM
HORIZONTAL MINIMUM HORI'A' BEND
ZONTAL 'B' BEND
RADIUS
RADIUS
in
in
47
50
68
78
1300
1400
2000
3500
800
970
2000
4500
1 27/32
1 31/32
2 11/16
3 1/16
51 7/32
55 1/8
78 13/16
137 29/32
31 17/32
38 7/32
78 13/16
177 5/16
50
70
85
100
1500
2500
3500
5000
1500
3000
4500
5500
1 31/32
2 3/4
3 11/32
3 15/16
60
98 1/2
137 29/32
197
27 29/32
118 3/16
177 5/16
216 11/16
75
125
175
180
1500
5000
9000
9000
2000
5000
13000
13000
2 31/32
4 15/16
6 29/32
7 3/32
59 3/32
197
354 19/32
354 19/32
78 13/16
197
512 3/16
512 3/16
Series 26
108
120
200
205
210
2500
4000
8000
9000
9400
2500
4000
8000
9000
9400
4 1/8
4 23/32
7 7/8
2 1/16
8 1/4
98 13/32
157 19/32
315 3/16
354 19/32
370 3/32
98 13/32
157 19/32
315 3/16
354 19/32
370 3/32
Series 30
100
108
120
150
210
225
332
2500
2875
4900
8000
12400
16000
22500
2500
2875
4900
8000
12400
16000
22500
3 15/16
4 1/4
4 23/32
5 29/32
8 1/4
8 7/8
13 1/16
98 1/2
113 3/16
192 1/32
315 3/16
488 3/16
630 13/32
885 13/16
98 1/2
113 3/16
192 1/32
315 3/16
488 3/16
630 13/32
885 13/16
2
3 3/8
15 3/4
47 1/4
15 3/4
Not suitable
3
6 3/16
19 11/16
19 11/16
20
Not suitable
Series 14
Series 19
Series 22
I-Track 19
51
86
400
1200
400*
Not suitable
I-Track 32
76
157
500
500
500*
Not suitable
Please contact our sales team for minimum bend radius requirements for Series 42 and 55 traveller cars.
* Manufacture of B-Bends for I-track 19 & 32 have length & radius limitations, please contact our sales team with your requirements.
‘B’ Bend
(Concave Side View)
‘B’ Bend
(Convex Side View)
CURVED TRACK
SPECIFICATION REQUIREMENTS
Specifications are required for each type of bend, including two critical
dimensions (three if possible), and clear drawings where possible.
Critical Dimension Required
Radius
R
and
O
Offset
L
Length of Track
C
Chord Length
C
Chord Length
OR
Radius
R
and
OR
Radius
R
and
OR
Offset
O
and
In many ‘B’ bend situations, the radius R is not known and it is easiest
to specify the curve by C (chord length) and O (offset) values. In these
cases, the radius the track is to follow MUST be constant.
It should be noted that:
• Although track bends may
• Light bends can be ‘sprung in’
• Not all track types are suited to
For best results, track should be
ordered pre-bent from Ronstan.
appear desirable to provide ideal
alignment and avoid angular
loads being applied to the car, in
a ball bearing system the bend
may reduce the load capacity of
the system by loading the balls
unevenly over the length of the
car.
both types of bends, and some
types of tracks cannot be curved
at all.
• A minimum track radius is specified
for each length of traveller car.
This is the tightest curve a car
will run around freely. Refer to the
recommendations on this page for
each track type regarding suitability
and minimum radius values.
during installation, however
considerable care must be
taken to ensure that the curves
are even with no tight spots
and that the track is not overbent (permanently deformed)
during installation.
Ordering
1. Specify the type of track profile
(by product no.)
2. Indicate the type of bend
required ‘A’ Bend (horizontal), or
‘B’ Bend (vertical) Concave or
Convex.
3. Provide the appropriate
dimensional specifications as
described above.