Truett & Osborn Cycle - Flywheels

3345 E. 31st Street South, Wichita Kansas 67216

316-682-4781

Professional

Service

Since 1970

Truett & Osborn Flywheels

Price Increase effective March 1, 2023

Part numbers for Truett & Osborn Flywheels are determined by combining the model code and the desired stroke length. This chart lists replacement flywheels (stock cubic inch displacement) by year and model. See stroke availability chart below for additional stroke lengths. Big Twin flywheels from 1939-1999 are available in two different styles (TorqueMonster Weight & Lighter Weight). The TorqueMonster flywheels are direct replacement weight (heavy) for years 1930-1981. The left side flywheel is much wider and heavier than the right side. The Lighter weight flywheels are the same width and weight for both right and left sides (similar to Evolution flywheels and S&S). Late Shovelheads and Evolutions from 1982-1999 the Lighter weight would be the direct replacement weight. TorqueMonster weight is available for these models as an option to increase low-end torque in Evos.

YEAR/MODEL FITMENT		SPECIFICATIONS			MODEL CODES
Years	Engine Size/Model	Stock Stroke	Outside Diameter	Notes	TorqueMonster Weight	Lighter Weight
1929-1973	Harley 45”	3 13/16	7 7/8			HD45
1929-1973	Special HD 45"	3 13/16	7 7/8	Uses XL C-pin/Rods	*	HD45XL

1952-1953	K-model	3 13/16	7 7/8	Press in shafts&C-pin	*	52K
1954-1956	KH-model	4 9/16	7 7/8	Lip on sprocket hole	*	54KH

1958-1970	XLR-model	3 13/16	7 7/8		*	XLR
1957-E1981	Sportster	3 13/16	7 7/8			EXL
L1981-1985	Sportster	3 13/16	7 7/8			LXL
1986-2003	Sportster*	3 13/16	7 7/8	special shafts*stroker only	*	EVXL

1912-1914	61" Twin Cylinder	3 1/2	9"		*	1912
1915-1929	61” J model	3 1/2	8 7/8	9" O.D. also avail.	*	J
1921-1929	74” JD model	3 31/32	8 7/8	9" O.D. also avail.	*	JD

1930-1936	74” Flathead	3 31/32	8 1/8	4" stroke also avail.	30T
1936	80" Flathead	4 1/4	8 1/8		30T
1937-1948	74”/80”Flathead*	4 9/32	8 9/32	Use 1941-later C-pin*	37T

1936-1940	61” Knucklehead*	3 ½	8 1/8	Use 1941-later C-pin*	36T
1941-1947	61” Knucklehead*	3 ½	8 ½	Use 1941-later C-pin*	39T
1948-1952	61” Panhead*	3 ½	8 ½	Use 1941-later C-pin*	39T

1941-1954	74” Pan/Knuckle	3 31/32	8 ½		39T	39
1955	74" Panhead	3 31/32	8 ½	56-64 Sprocket Shaft	56T	56
1956-1969	74” Pan/Shovel	3 31/32	8 ½		56T	56
1970-1971	74” Shovelhead	3 31/32	8 ½		70T	56
1972-1981	74” Shovelhead*	3 31/32	8 ½	82-up Sprocket Shaft*	82/72T	82/72
1972-1981	80” Shovelhead*	4 ¼	8 ½	82-up Sprocket Shaft*	82/72T	82/72
1982-1984	80” Shovelhead	4 ¼	8 ½		82T	82
1985-1999	80” Evolution	4 ¼	8 ½		82T	82

STROKE AVAILABILITY CHART

* = Available at extra charge for reducing outside diameter *see note* X = Available

Harley Davidson Flywheels

Model Code & Stroke
3 1/2" 3-13/16" 3-31/32" 4" 4-1/4" 4-5/16" 4 9/32" 4-7/16" 4 9/16" 4-1/2" 4-5/8" 4-3/4" 5"

HD45 X X X X

45XL (XL C-pin) X X X X

52K X

54KH X

XLR (Race XL) X

EXL & LXL X X X X X X

EVXL X X

1912-1914 X

J & JD Model X X X X X X

30T (flathead) X X X

37T (flathead) * * X * * * *

36T (OHV) X * * * * * *

39 & 39T X X X X X X X

56 & 56T X X X X X X

70T X

82/72 & 82/72T X X X X X X

82 & 82T X X X X X

Flywheels for 74" & 80" OHV models are available in Lighter Weight or Torquemonster version.
Flywheels for 61" OHV & Big Twin Flathead models are only available in Torquemonster version.*see note*
Flywheels for 45" Flathead, K-model, Sportster, Indian and JD models only available in stock Weight.

Indian Flywheels

YEAR/MODEL FITMENT

SPECIFICATIONS

MODEL CODES

Years

Engine Size/Model

Stock Stroke

Outside Diameter

Notes
TorqueMonster Weight
Lighter Weight

1916-1924 61" Power Plus
3 31/32

8"

*

IPP

1920-1931 37" Scout (All models)
3 1/16

7 3/4

*

IS37

1928-1931 45" 101 Scout
3 1/2

7 3/4

*

IS101

1934-1942 45" Sport Scout
3 1/2

7 3/4

*

IS45

1934-1942 45" Sport Scout
stroker only

7 3/4

Uses XL C-pin/Rods

*

IS45XL

1922-1948 74" Indian Chief
4 7/16

8 1/8

*

I.C.

1950-1953 80" Indian Chief
4 13/16

8 1/8

*

I.C.

Indian Stroke Availability Chart

Model Code & Stroke
3 1/16 3 1/2" 3 31/32" 4-7/16" 4 13/16" 5" 5 1/4" 5 1/2"

IPP        - Indian Power Plus       61" X

IS37      - All Scout models         37" X

IS101    - 101 Scout models        45"
X X

IS45      - Sport Scout models     45" X X

IS45XL - Sport Scout (XL C-pin) 45" X

I.C.        - Chief models        74"/80" X X

Click here for printable page

TorqueMonster Flywheels

$600.00

Lighter Weight Flywheels

$550.00

*Please Note*

JD ,45XL, XLR, EVXL, K, KH, and Indian flywheels are specialty flywheels, priced the same as Torquemonster Flywheels. HD45 flywheels & Sportster flywheels are priced the same as Lighter Weight Flywheels.

*Please Note* 1972-1981 Original Harley flywheels used sprocket shaft part # 24001-72. This shaft was very large taper, set at 8 degrees, and had a lot of problems with slippage in the flywheel. We make our flywheels for these years to use the 1982-later 23909-80 shaft.

*Please Note* Flywheels for 1937-1948 Big Twin Flathead and 1936-1952 61" OHV are made with the 1941-later 74"OHV crankpin, NOT the stepped crankpin as original.

I only make the stock stroke flywheels (4-9/32 & 3-1/2) in the TorqueMonster version, but since we make them with the later crankpin, the only difference between these and 1939-later OHV flywheels is the outside diameter.

We can take a set of 1939-later OHV Lighter Weight or TorqueMonster flywheels that are available in other strokes and turn down the outside diameter to be used in Flathead or 61" Knuckle/Pan engines.

*Please Note* Flywheels for Evolution Sportster models require the use of special "big taper" S&S brand sprocket shaft and pinion shaft. Flywheels are NOT available in stock stroke. Pistons must be custom made. Other parts such as pinion gears and bearings must also be changed, depending on the year/model. Please refer to the links below for more information on this conversion.

1986 only 1987 only

1988-1990 1991-1999