Modified Stock Gearing - Boston Gear

Boston Gear chain drive tensioners improve drive
performance by eliminating whipping and slipping of loose
chains. They reduce vibration, noise and maintenance and
provide additional life to drive components. They are also
suitable for flat-face and V-Belt drive systems and are
provided with a grease fitting for lubricating idler bearings
other than Bost-Bronz.
All tensioners are constructed of structural steel and are
available for use with Roller Chains up to 1-1/2” Piitch. No.
120.
Roller Chain Drive Tensioners
Screw Adjustable/Spring Adjustable/Shaft Mounted
Non-Adjustable (Drive Positioners)
Installation Instructions
• Idlers should be located on the slack side of the drive chain.
• Chain idlers should be run on the outside of the chain.
• Idler sprockets should have at least three teeth engaged
with the chain.
• Idlers, when used on the outside of the drive, should be
located approximately 1/3 of the center distance from the
large sprocket.
• Idlers, when used on the inside of the drive, should be
located approximately 1/3 of the center distance from the
large sprocket.
• Tensioning that is too tight causes excessive wear on the
chain and bearings.
• Tensioning that is too loose allows chain vibration, causing
loss of horsepower or wear.
ORDER BY CATALOG NUMBER OR ITEM CODE
For Use
No.
Hole
Catalog Item
with
of
Diameter
Number Code
Chain No.
Teeth
12 35B12TI-8 48901
35 1/2 15 35B15TI-8 48902
18 35B18TI-8 48903
9 40B9TI-8 48904
1/2 12 40B12TI-8 48905
40 15 40B15TI-8 48906
12 40B12TI-14 48910
7/8 15 40B15TI-14 48911
18 40B18TI-14 48912
9 41B9TI-8 48907
1/2 12 41B12TI-8 48908
41 15 41B15TI-8 48909
7/8 15 41B15TI-14 48913
18 41B18TI-14 48914
12 50B12TI-14 48915
50 7/8 15 50B15TI-14 48916
18 50B18TI-14 48917
12 60B12TI-14 48918
7/8 15 60B15TI-14 48919
60 18 60B18TI-14 48920
12 60B12TI-18 48921
1-1/8 15 60B15TI-18 48922
18 60B18TI-18 48923
12 80B12TI-18 48924
80 1-1/8 15 80B15TI-18 48925
18 80B18TI-18 48926
Idler Sprockets
Boston stocks a wide range of idler sprockets for use with its
chain drive tensioners and positioners. In addition special
sizes and configurations can be furnished to order. All idlers
are equipped with Bost-Bronz, oil impregnated bushings.
Grease lubrication is not recommended. Use normal
relubrication procedure for oil-impregnated bearings.
H
P-1930-BG 04/10 Boston Gear 800-825-6544 293