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Synchronous Belts
Installation Guide
12. How to install belts
Before installation, inspect the belt for damage. Belts should
never appear crimped or bent to a diameter less than the
minimum recommended sprocket diameter.
Always move the drive unit so you can easily slip the belts into
the grooves without force.
Shorten the center distance or release the tensioning idler to
install the belt. Do not pry the belt on the sprocket. Refer to the
following Center Distance Allowance tables for the required
center distance adjustment.
Place the belt on each sprocket and ensure proper
engagement between the sprocket and belt teeth.
Lengthen the center distance or adjust the tensioning idler to
remove any belt slack.
Apply the following center distance allowances for Hawk Pd®
and Falcon Pd.® A center distance adjustment or decrease
in center distance, is necessary to install a belt. In addition, an
increase in center distance will be necessary for proper
tensioning. If you install a belt together with sprockets, allow the
following decrease in center distance for installation and
an increase in center distance for tensioning.
Center Distance
Longer Center Distance for Synchronous Belt Take-Up
Shorter Center Distance
for Synchronous Belt Installation
If you install a belt over one flanged sprocket and one
unflanged sprocket with the sprockets already installed on the
drive, allow the following decrease in center distance for
installation and increase in center distance for tensioning.
If you install the belt over two flanged sprockets that are
already installed on the drive, allow the following decrease in
center distance for installation and increase in center distance
for tensioning:
Consider the following center distance allowances when
installing SilentSync® sprockets.
Since flanges are not necessary on SilentSync® drives, only
one table of center distance allowances is provided.
Synchronous Belts
Installation Guide
Pitch Length
Range (mm)
Allowance (decrease)
for Installation
Allowance (increase)
for Take-Up
8m, 14m Belts
(mm/in.)
8m, 14m Belts
(mm/in.)
Less than 1525
2.5/0.1
2.5/0.1
1525-3050
5.0/0.2
5.0/0.2
Greater than 3050 7.5/0.3
7.5/0.3
Pitch Length
Range (mm)
Allowance (decrease)
for Installation
Allowance
(increase)
for Take-Up
8m Belts
(mm/in.)
14m Belts
(mm/in.)
8m, 14m Belts
(mm/in.)
Less than 1525
22.5/0.9
36.5/1.4
2.5/0.1
1525-3050
25.0/1.0
39.0/1.5
5.0/0.2
Greater than 3050 27.5/1.1
41.5/1.6
7.5/0.3
Pitch Length
Range (mm)
Allowance (decrease)
for Installation
Allowance
(increase)
for Take-Up
8m Belts
(mm/in.)
14m Belts
(mm/in.)
8m, 14m Belts
(mm/in.)
Less than 1525
34.5/1.4
59.2/2.3
2.5/0.1
1525-3050
37.0/1.5
62.0/2.4
5.0/0.2
Greater than 3050 39.5/1.6
64.5/2.5
7.5/0.3
Pitch Length
Range (mm)
Allowance (decrease)
for Installation
Allowance
(increase)
for Take-Up
Yellow, White,
Purple Belts
(mm/in.)
Blue, Green,
Orange, Red
(mm/in.)
8m, 14m Belts
(mm/in.)
Less than 1525
10.1/0.4
15.2/0.6
2.5/0.1
Greater than 1525 15.2/0.6
17.8/0.7
5.0/0.2
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