Truett & Osborn Flywheels

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 and Lighter weight). The TorqueMonster flywheels are direct replacement weight (heavy) for years 1930-81. The left side flywheel is much wider & 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 Shoveheads 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 Price Qty.  

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 and JD models are only available in stock weight.

NOTE: JD, 45XL, XLR, EVXL, K and KH flywheels are specialty flywheels, priced the same as TorqueMonster flywheels. HD45 flywheels & Sportster flywheels are priced the same as Lighter weight flywheels.

NOTE: 1972-81 Original Harley flywheels used sprocket shaft part #24001-72. This shaft was very large taper, set at 8 degrees, & had a lot of problems with slippage in the flywheel. Truett & Osborn makes their flywheels for these years to use the 1982-later 23909-80 shaft.

NOTE: Flywheels for 1937-48 Big Twin Flathead and 1936-40 61" Knucklehead are made with the 1941-later OHV crankpin, NOT the stepped crankpin as original. Truett & Osborn only makes the stock stroke flywheels (4-9/32 & 3-1/2) in the TorqueMonster version, but since they make them with the later crankpin, the only difference between these and 1939-later OHV flywheels is the outside diameter. They can take a set of 1939-later OHV Lighter weight or TorqueMonster flywheels that are available in other strokes and turn the O.D. to be used in Flathead or 61" Knuckle engines.

NOTE: Flywheels for Evolution Sportster models require the use of special "big taper" S&S brand sprocket shaft and pinion shaft. Other parts such as pinion gears and bearings must also be changed, depending on the year/model.

* = Available at extra charge for reducing outside diameter **See Note** X = Available
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
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

** Please call for pricing and lead time.

Return Policy: The Good Old Motorcycle Parts Company accepts returns and/or exchanges on products within (30) days of receipt. We DO NOT accept any returns or exchanges on Electrical Components (remember if it smells burnt, it is burnt). All warranties on electrical components must be taken up with the individual manufacturer. The returned product must be in the original packaging, unopened and unaltered. The buyer is responsible for all shipping charges to exchange or return an item. Shipping charges will only be refunded on defective items, misrepresented items or items that may have been sent to you in error. If you are unsure about an item, a size or a fit, please contact us prior to purchasing the item.