Azusa: Chain Data

2010

Roller Chain Number System

Chain numbers used by ANSI (American National Standard Institute) are based on the number “8,” which represents one inch. Therefore, #80 chain has a 1″ pitch; #35 with a “3” as the first number, has a 3/8″ pitch; #40 with a “4” as the first number has a 1/2″ (4/8) pitch, and so on. All figures after the first number are variations within that pitch. The variations can be the roller diameter, the roller width, the side plate thickness or characteristics of the pin.

#35 Space Chain is interesting because it is a hybrid chain composed of both #35 and #41 elements. It has a 3/8″ pitch and uses #35 chain side plates, but has #41 Chain components as well, a 1/2″ pitch pin and bushing.

The International Organization for Standardization (ISO) uses a similar system, but one in which the first two digits are based on the number “16” which represents one inch. In the ISO system, #35 chain is 06, #40 is 08, #50 is 10 and #80 is 16.

However, #219 Chain, although an ISO number, does not fit into either of the above two patterns.


Chain Sizes

Presently, there are four pitch sizes of roller chain used in karting:

Pitch (inches)  Chain Number          Pitches Per Foot
   .306            #219                     39.2
   .375            #35 #35 Space            32
   .500            #40/425 #420 #428        24
   .625            #520                     19.2

Generally, the fewer pitches per foot, the higher the tensile strength.


Chain Care

  • Do: Replace chain that has stretched more than 1/4″ per foot.
  • Do: Install the spring clip on the connecting link so that the closed end faces in the direction of the chain travel.
  • Do: Replace worn sprockets. (Worn sprockets lose their tooth form and become “pointy.”)
  • Do: Use a straight edge to align both sprockets in the same plane.
  • Don’t: Use a new chain on an old, worn sprocket and vice versa.
  • Don’t: Use more than one connecting link on a length of chain.
  • Don’t: Allow your chain to be too tight.

#219 versus #35 Roller Chain

#219 chain is similar in weight to #35, but its smaller pitch provides more teeth on a given diameter sprocket. Finer teeth on both drive and driven sprockets have an advantage; they provide more gear ratios for a given range of sprocket diameters and overcome clearance limitations inherent in larger diameter #35 sprockets. For example:

         #219 Sprockets         #35 Sprockets
         OD       Teeth         OD       Teeth
From:   7.00"       70         7.02"       57
To:    10.02"      101        10.00"       82

Ratios* Possible:   31                     25

*Within the same OD range for a given drive sprocket.

If you don’t need the clearance or the extra ratios, then #35 has the advantage:

                              #35        #35 Space         #219
Weight per Foot (lbs)        .222          .234            .226
Tensile Strength (average)  2,100 lbs     2,100 lbs       1,962 lbs
Azusa Suggested List         $2.27         $3.32           $9.80
 (per foot-8/96)**

**Some dealers add their freight costs.


Chain Characteristics

Chain Size Pitch RollerWidth AverageTensile(lbs) SprocketThickness
219 .306″ .183″ 1962 .125 to .160″
35 .375″ .1875″ 2100 .125 to .160″
40 .500″ .3125″ 3700 .249 to .284″
41 .500″ .250″ 2000 .207 to .227″
420 .500″ .250″ 3700 .207 to .227″
425 .500″ .3125″ 3700 .249 to .284″
428 .500″ .3125″ 4200 .249 to .284″
520 .625″ .250″ 6100 .207 to .227″
530 (50) .625″ .375″ 6100 .307 to .343″

Azusa Engineering, Inc. carries all of the above chain, plus others, and manufactures sprockets for all. Ask your dealer.

Comments are closed.