Sputhe originated the 5-speed transmission for 4-speed frames and the only kick-starter with a one-piece main shaft.  Sputhe has the only after market transmissions that use only American-made parts.  Sputhe manufactures their cases, lids, trap doors, release covers, billet pillow blocks, snap rings, hardened thrust washers, springs and shifter ratchet assembly.  All Sputhe transmissions feature American-made gears and shafts.

Sputhe transmissions are available with electronic speedometer pickup, billet trap door, Karata pulley and either cable or hydraulic billet clutch release assemblies. 

  • Kick-starter and end cover sold separately.
  • Hydraulic cover sold separately.
  • Electronic speedometer pick-up sold separately.


Hydraulic clutch release

Cable clutch release


The Sputhe 5-speed Kick Starter Assembly adapts a 5-speed transmission from ’80 to late ’84 to accept 4-speed kicker units. The assembly kit features a one-piece main shaft and heavy-duty access door for strength and reliability. Includes door with bearing and snap rings, main shaft with spacer and nut, clutch rod center and mounting bolts. Finish, “as cast”. All other parts required are stock H-D.

Part #8500B


Sputhe Softail Transmissions are a superior replacement for the stock unit.  The gear ratios are the same as stock, except 1stgear, which is slightly higher.  All gears, as well as the shift drum turn on needle bearings.  If replacement parts are ever needed, they are readily available from either Sputhe Industries. or your Harley dealer.

The case is cast in tough 356A-T6 aluminum, without the familiar OEM waffle pattern.  The Sputhe case contributes to both a cleaner exterior that better lends itself to polishing.  All components are American made. 

Shown with clutch cable release end cover.




Softail Gear Ratios 1986 to 1999

Year/Type Tranny Pulley Rear Wheel Pulley Belt Size Required Engine Sprocket Clutch Sprocket Overall Ratio
1986-1992 FXST 32 70 132 (40023-86) 24 37 3.37
1993 FXST 32 61 128 (40012-90) 24 37 2.94
1994 32 70 132 (40023-86) 24 or 25 36 or 37 3.37 (24X37) 3.15 (25X36)
1995-1999 32 65 130 (40017-94) 25 36 2.93
Custom 34 61 128 24 37 2.77
Custom 29 70 132 24 37 3.72
Custom 34 65 130 24 37 2.95
Custom 29 65 130 24 37 3.46


Transmission Ratios
  Road Race Super Close Close Ratio Mid Ratio Wide Ratio Super Wide
5th 1.00 1.00 1.00 1.00 1.00 1.00
4th 1.16 1.20 1.23 1.20 1.23 1.34
3rd 1.52 1.55 1.60 1.55 1.60 1.73
2nd 2.09 2.16 2.21 2.16 2.21 2.43
1st 2.78 2.84 2.94 3.14 3.25 3.53



Part #8000T

Close or Wide Ratio

Shown with polished case, cable clutch release Shown with hydraulic clutch release

Sputhe transmission cases allow Harley-Davidson Evolution 5-speed transmissions to be adapted to 1970* and up Big Twins with non-rubber mount 4-speed frames.  They clear all stock exhaust pipes, oil tanks, battery boxes and brake linkages, etc.

 Harley’s EVO 5-speed has better gear ratios and it is stronger than a 4-speed.  It shifts faster and smoother and cuts 1/2 second off the quarter mile time.  Every gear turns on needle bearings, even the shift drum turns on needle bearings.  Materials are better and tolerances are much tighter than in the four speed.

 The ratios allow you much more freedom to tailor your bike to your particular riding style.  It also makes your bike more versatile.  You can have a higher high, a lower low and closer ratio gearing, all at the same time.

 This is the one piece of speed equipment that will increase acceleration, improve fuel mileage and increase engine life.  It makes for more pleasant riding in traffic and more comfortable highway cruising all at the same time.  If replacement parts are ever needed, they are readily available from Sputhe Industries. or your Harley-Davidson dealer.

 *Can be used on 1955 – 1969 models with a modified primary drive.


Part #8000TR

Owners of 1970 to 1984 Harley-Davidson FL’s and FX’s can replace their stock 4-speed transmission, with Sputhe Industries new 5-speed plus reverse transmission.  The reverse gear transmission is the latest development in Sputhe’s long line of special application transmissions. 

The internals of the 5 forward speeds are borrowed directly from Harley-Davidson’s Evolution 5-speed transmission including the deep 3.24 to 1 first gear.  Shifting of the forward gears is accomplished using the normal foot lever.

There is a third shaft located inside a specially designed Sputhe transmission case.  This reverse shaft has two integral gears that engage first gear on the lay shaft and fifth gear on the main-shaft resulting in a low reverse gear ratio.

A separate hand operated lever engages reverse, which is on the right side of the transmission.  An excellent feature of the shifting mechanism is Sputhe’s patented* compound lock out system.  Unless the transmission is in neutral, reverse is locked out.  Once reverse is engaged, the forward gears are locked out.  Furthermore the reverse lever has a safety latch preventing accidental movement of the reverse lever in either the engaged or disengaged position.

Installation is quite straightforward.  The only modification required to install the reverse gear transmission is to remove a bracket on the right frame rail.  The transmission comes completely assembled and includes a billet mounting plate and clutch cable.

Like all Sputhe transmissions, the 5-speed plus reverse uses only top quality American made parts including Sputhe’s own billet pillow blocks and patented PosiShift – which makes it impossible to over shift into a false neutral.

The case comes in an as-cast finish.  The forward shift lever, top cover and all bolts are chrome plated.  The bearing housing and side cover are polished billet aluminum.  The reverse shifter is polished stainless steel.

 *U.S. Patent 6,076,416





 Part #8263

Harley-Davidson’s first use of the five-speed transmission was on the 1980 FLT touring bike.  Those motorcycles used an enclosed chain final drive.  If transmission oil leaked past the sprocket spacer, it was not a problem because it ended up inside the chain case.

To eliminate this potential problem, all Sputhe 8000 series transmissions, 8000B and 8500B 5-speed transmission kits come with our sprocket spacer.

The spacer incorporates three distinct improvements over the original Harley-Davidson part number 33334-79

  1. Our sprocket spacer is machined from 303 Stainless steel, so that it cannot rust
  2. The O.D. is precision ground for maximum sealing effectiveness and minimum seal wear
  3. Sputhe has machined a bevel in the spacer and installed a Quad Seal (Sputhe Part #8264) between the main bearing and the spacer.

This spacer can be installed on any early style genuine Sputhe or Sputhe imitation, five in a four transmission as well as 1982 through 1985 FXR’s.


Speedometer Sensor Plug

Polishes billet aluminum plug replaces the electronic sensor on all Big Twin transmission cases 1994 to present.  Supplied with O-ring.


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Tel: +1 (530) 268-0887 

PO BOX 2553

Grass Valley CA 95945

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