Page 23 of High Performance Cams & Gears Catalog by Andrews High Performance Cams & Gears
BIG TWIN TRANSMISSION BELT SPROCKETS
Fits all EV80 and Twin 88 5 and 6 speed transmissions, 29, 30, 31, 33 and 34 teeth available
POWER SPROCKETS:
29 Tooth sprockets . . . . 9% MORE RPM*
Part #290290 ('85-'93)
Part #290294 ('94-up)
30 Tooth sprockets . . . . . 6% MORE RPM*
Part #290304 ('94-up)
Part #290300 ('85-'93)
OVERDRIVE SPROCKETS:
34T sprockets. . . . . . . . . . 6% LESS RPM*
(180 RPM drop in engine RPM 60 MPH)
Part #290344 ('94-up)
Part #290340 ('85-'93)
*More RPM means more power; less RPM means
more MPH than stock 32 T sprocket.
POWER SPROCKETS:
31T sprockets. . . . . . . . . 3% MORE RPM*
Part #290314 ('94-up)
Part #290310 ('85-'93)
CRUISING SPROCKETS:
33T sprockets. . . . . . . . . . 3% LESS RPM*
Part #290334 ('94-up)
Part #290330 ('85-'93)
Sprocket Tooth Counts Ratios 1994-2001
(36 T clutch-25 T engine sprocket)
TRANS.
REAR WHEEL
OVERALL
29
70
3.48
30
70
3.36
31
70
3.25
32
(Stock)
70
3.15
33
70
3.05
34
70
2.96
29
65 ('95 softail)
3.23
30
65 ('95 softail)
3.12
31
65 ('95 softail)
3.02
32
(Stock)
65 ('95 softail)
2.93
33
65 ('95 softail)
2.83
34
65 ('95 softail)
2.75
Sprocket Tooth Counts Ratios 1985-1993
(37 T clutch-24 T engine sprocket)
TRANS.
REAR WHEEL
OVERALL
29
70
3.72
30
70
3.60
31
70
3.48
32
(Stock)
70
3.37
33
70
3.27
34
70
3.17
29
61 ('93 softail)
3.24
30
61 ('93 softail)
3.13
31
61 ('93 softail)
3.03
32
(Stock)
61 ('93 softail)
2.94
33
61 ('93 softail)
2.85
34
61 ('93 softail)
2.76
Installing a transmission sprocket with more or less teeth than stock requires adjusting the rear axle forward (for more teeth on sprocket)
or backwards (for less teeth on sprocket).
Rear axle position adjustment for each one tooth change on transmission sprocket .125 inches (3.2mm).
Rear axle position adjustment for each one tooth change in belt length .280 inches (7.1 mm).
If there is not enough axle adjustment at the rear frame, it may be necessary to use a belt with more or less teeth. There are at least 8 different drive belts available at this time. They have 126, 128, 130, 132, 133, 135, 136 or 139 teeth. The only sure way to tell which belt you
have is to physically count the teeth.
(Use a paint mark for reference).
1984-1993 EV80 overall final drive
ratio (engine to rear wheel) is 3.37 to 1
Overall 37 24 x (70 32 3.37
1994-2001 EV80 overall final drive
ratio (engine to rear wheel) is 3.15 to 1
Andrews sprocket pulleys match 1994 style design. This arrangement has the advantage of 50% longer internal spline length compared to the early design. New style pulleys will fit both early
(1985-1993) and late transmission shafts. Overall Belt drive ratio
changes of 3%, 6% or 9% are very noticeable to a rider! All 85-
93 pulley kits have new style spacer, lock ring, retainer bolts
and seals included as part of the kit. Pulley kits for 94-up
must use original stock seal and lock ring.
BELT DRIVE SPROCKETS INSTALLATION NOTES
Transmission (32 T )
Rear wheel (70 T )
Clutch (37 T )
Engine (24 T )
23
www.andrewsproducts.com
431 Kingston Court
Mount Prospect, IL 60056
Phone: 847-759-0190
Fax: 847-759-0848
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