APPLICATIONS

SOFTWARE
Clutch Pro-M software used to predict the effect of changes in lockup weights and spring pressure settings on the performance of a drag race clutch. For use with BANDIT or MTC lockups. Input your number and size of clutch plates, coefficient of friction, static spring pressure, number of lockup levers, lever spring pressures, lever counterweights, first gear ratio, primary ratio, and torque/rpm figures, and receive calculations of total pressure plate load at given engine rpms and theoretical lockup points in low and high gear.

Clutch Pro-M software - MS-DOS only -
NOTE: Software is NON-RETURNABLE after opening package
191001
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APPLICATION NOTES
All 5-speed Big Twin clutches for ’90 and later will fit 6-speed conversions - select the appropriate clutch for the year of motorcycle - ’85 - ’89 bikes can use a ’90 6-speed conversion with a 039001 clutch and a ‘90 pushrod.

’85 - ’89 5-speed Big Twins can be converted from a tapered transmission mainshaft to a splined transmission mainshaft by using a 1990 mainshaft and pushrod. Use 1990 shaft only - the 1991 and later shaft has a smaller diameter through 5th gear. Our 039001 clutch will then fit this application.

Sportsman Superclutches will fit other manufacturer’s belt drives designed to use the corresponding stock HD clutch. On Karata drives with a cover over the clutch on the rear pulley - the cover on a 4” Karata pulley will clear the Sportsman Superclutch, the cover on a 3” Karata pulley will not clear the sportsman clutch. The Kevlar plates run well dry.

5-speed in 4-speed Big Twin conversions - use ‘79 mainshaft to align clutch and engine sprocket shaft correctly. Later shafts move the clutch farther outboard and prevent proper alignment. When using the ‘79 mainshaft and pushrod, select the clutch as though the transmission were still the original 4-speed. There currently is no splined mainshaft for the 5-speed which will locate the clutch in the proper location for the 4 to 5-speed conversion.

’84 - ’90 Evolution 4-speed Sportsters with charging system on the clutch - we have no clutch available at this time to use the HD alternator - see section 21.

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FRICTION PLATE SELECTION
All Sportster belt drives and Big Twin chain and belt drive clutches (except Sportsman Superclutch)
Friction plates are available for these models in 3 choices of material: Kevlar (green), Alto (red), and Carbon-Ceramic (gray). Wet applications can use the Kevlar or the Alto, and dry applications can use Kevlar or Carbon-Ceramic.

WET: We recommend Kevlar as your first choice in a wet application - Kevlar is very durable and consistent, and requires slightly less spring pressure than the red Alto for a given horsepower output. The red Alto is also very durable and consistent, but requires slightly more spring pressure for a given horsepower output. The main advantage with red Alto plates is that they are extremely free releasing under all conditions and normally tolerant of a variety of lubricants. An additional advantage is that Alto has a lifetime guarantee on their plates.

NOTE: We recommend the use of ONLY automatic transmission fluid or Golden Spectro Gear SAE 80 Primary Chaincase Lubricant in our clutches. DO NOT use the HD oil or similar oils in the primary, especially with Kevlar plates. Using the HD oil will make the clutch drag and slip. ATF is inexpensive and works great, but can be difficult to prevent leakage in some bikes where the engine to primary case seal is not perfect. Golden Spectro 80 contains friction modifiers which actually increase the friction between the plates and allows the clutch to carry more power with the same spring pressure but is slightly higher viscosity than the ATF and can aggravate clutch drag in a bike with limited release travel. DO NOT use a full synthetic oil, these are often too “slippery” and will make the clutch slip.

DRY:Here we recommend either the Kevlar or the Carbon-Ceramic for Street riding and Carbon-Ceramic for maximum effort race-only bikes. The Carbon-Ceramic is more consistent and tolerant of the slipping that occurs when using a properly setup lockup than Kevlar.

All Big Twin Sportsman Superclutches - 039601 & 039801
Available only with Kevlar friction plates - works great! See note above about primary lubricants.

Sportster Chain Drives
Friction plates are available for these models in 2 choices of material: Kevlar (green) and Carbon-Ceramic (gray). Wet applications can use the Kevlar, and dry applications can use Kevlar or Carbon-Ceramic. To run a dry clutch in a Sportster chain drive, you must block off the transmission trap door so that you can run oil only in the transmission, and manually lubricate the chain before each run. See note above about primary lubricants - we recommend use of Golden Spectro Primary Chaincase Lubricant (Golden Spectro Gear Lubricant SAE 80) in the transmission and primary drive.

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SPRING SELECTION
A. All Big Twin chain and belt drive Superclutches, Big Twin Sportsman Superclutches, Sportster belt drives, and Sportster chain drives with lockups

There are 4 springs available for these clutches. In order from lightest to heaviest they are short gold PN154406 (light), long gold PN154401 (standard), Red PN154402 (medium), and Gray PN154403 (Heavy Duty). We recommend the Short gold springs for engines below 75 horsepower where the rider needs the very lightest lever pull possible. We recommend the long gold springs for engines up to about 90 HP, the red springs for up to 120 HP and the gray springs for engines over 120 HP. These are “safe” recommendations - you may be able to use less pressure with good results. Spring pressure requirements are altered by the riding style of the rider. A motorcycle which is shifted at wide open throttle will require more spring pressure than an identical motorcycle which has the throttle rolled closed during shifts. If a spring choice is not specified, Sportsman Superclutches and standard Superclutches not equipped with a lockup are shipped with gray and long gold springs.

The spring pressure can be adjusted by turning the spring retaining nut to place the spring retaining collar below the surface of the pressure plate to shorten the springs’ compressed length. When the collar is flush with the pressure plate the spring’s compressed length is 1.250. The collar can be run as far down as .250 below the pressure plate. This will make the spring’s compressed length 1.000. 1.000 is the minimum length recommended for all springs to avoid the possibility of coil bind. When adjusting the springs, make sure that all 6 collars are set at the same distance below the pressure plate (±.010) so that the pressure plate is not pulled out of true by unequal spring pressure when released. If the pressure plate does not run true, the clutch will not release cleanly. If the pressure plate runs out .020”, this shortens the effective release travel by .010”. We recommend using a dial caliper to measure the preload depth. If you cannot use a dial caliper to measure the preload, each full turn of the spring retaining nut compresses the spring .036”, and 7 turns equals .250”. Applying more pressure than necessary will not affect the operation of the clutch, but will make the lever effort higher than necessary. The chart below shows the pressure produced by 6 springs. Heavier springs also have a higher spring rate, so a gray spring set at 300 lbs will feel stiffer to the rider than a red spring set at 300 lbs. The exceptions to this are the 2 types of gold springs - the short and long gold springs have the same spring rate.

Springs
Light PN154406(short gold)(1.75")
Standard PN154401(long gold)(1.875")
Medium PN154402(red)
Heavy Duty PN154403(gray)
Minimum Pressure (lbs)
144
210
258
276
Maximum Pressure (lbs)
240
300
372
507

Clutches equipped with a lockup unit must be equipped with lighter springs than the same application without a lockup in order to take advantage of the adjustable lockup. When installing a lockup, we recommend starting with red springs set at 1.250 installed height and adjusting spring pressure higher or lower from there as the bike and conditions demand. Lighter static spring pressure will allow the bike to leave the line without spinning the tire, and must be compensated for by more counterweight on the arms to keep the clutch from slipping in high gear.

B. 077101 Sportster clutches

This clutch uses the same spring choices as above, but has spring cups .125“ shorter than the clutches listed above. When the spring collars are set flush with the pressure plate, the installed height of the spring is 1.125” and the collar can be set to a maximum of .125” below flush without encountering coil bind.

C. 079001, 079003, & 079005 Sportster clutches

Because of the space limitations of the 5-speed Sportster, these clutches use a very short very stiff spring with a limited amount of adjustment. Because of this the clutch is available with 3, 4 or 6 springs to suit the intended application. The 079001 uses 3 springs, the 079003 uses 4 springs and the 079005 uses 6 springs. The maximum installed height of the springs allowed by the cups and collars is .660”. The minimum installed height of the green springs which will allow for adequate pressure plate travel (.070) without coil bind is .570”. An installed height of .660” is achieved when the steel collar is .210” below the pressure plate and .570” when the collar is .300” below the pressure plate. The blue springs coil bind at any installed height less than .660”, so they are not adjustable.

Spring Pressure
@.660 ht
Pressure
@.630 ht
Pressure
@.600 ht
Pressure
@.570 ht
3 Short Green
PN 154411
285 lbs 315 lbs 345 lbs 375 lbs
3 Short Blue
PN 154412
510 lbs coil bind coil bind coil bind
4 Green PN 154411
380 lbs 420 lbs 460 lbs 500 lbs
2 Short Blue @ .660
& 2 Short Green @ >>>
530 lbs 550 lbs 570 lbs 590 lbs
4 Short Blue
PN 154412
680 lbs coil bind coil bind coil bind
6 Short Green
PN 154411
570 lbs 630 lbs 690 lbs 750 lbs
6 Short Blue
PN 154412
NOT RECOMMENDED
1020 lbs coil bind coil bind coil bind

The chart illustrates what spring pressure can be achieved in the 3 clutches. We recommend the 079001 / 079002 3 spring clutch when you must have low spring pressure for a light lever pull on a mid-range output motor. The 079003 / 079004 4 spring clutch is the most versatile clutch for a large motor because of the relatively wide range of adjustment available, and is our first recommendation for hot-rod Sportsters. The 6 spring 079005 / 079006 was first built for a nitro fueled Bonneville streamliner where power was at a maximum and space was at a minimum and the clutch was operated by a compressed air cylinder. We do not recommend PN079005 / 079006 6 spring clutch for gasoline fueled motorcycles. Over 500 lbs spring pressure may cause failure in the stock release mechanism or cable.

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SPRING PRESSURES

For all Big Twin, Belt Drives and Sportsters except 79001-79006 clutches.

Spring Color
Blue
Grey
Red
1.875" Gold
1.750" Gold
Spring Cup
Depth
 
Height
Lbs.
Collar
Spring
1.375"
Flush
1.250"
ea
79
44
43
35
25
x6
474
264
258
210
150
-.050"
1.200"
ea
95
52
46
38
29
x6
570
312
276
228
174
-.100"
1.150"
ea
111
60
50
41
32
x6
666
360
300
246
192
-.150"
1.100"
ea
127
68
54
44
35
x6
762
408
324
264
210
-.200"
1.050"
ea
143
76
58
47
38
x6
858
456
348
282
228
-.250"
1.000"
ea
159
84
62
50
41
x6
954
504
372
300
246
 
 
 
1.250"
(77101)
Flush
1.125"
ea
119
64
52
42
x6
714
384
312
252
-.050"
1.075"
ea
135
72
56
46
x6
810
432
336
276
-.100"
1.025"
ea
151
80
60
49
x6
906
480
360
294
-.125"
1.000"
ea
159
84
62
50
x6
954
504
372
300

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