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BSA-Chains

Chain

Model/Year

Size/Links

Sprocket teeth front/rear

Generator

C10 C11

8mm x 48r

 
 

A7 A10

8mm x 52r

11/27

Transmission

C-mod

1/2" x 5/16" x 69-70

16-17/43

 

B-mod

1/2" x 5/16" x 67-70

17-19/43

 

Gold Star

1/2" x 5/16" x 66-71

18-23/43

 

M-mod

1/2" x 5/16" x 68-70

16-21/43

 

(C15 & B44) unit model

3/8" duplex x 68-75

18-28/52

 

A7 A10 plunger

3/8" duplex x 80

27/54

 

A7 A10 S/A

1/2" x 5/16" x 67-70

18-23/43

 

A50 A65

3/8" triplex x 80r

28/58

Rear chain

C-mod

1/2" x 5/16" x 104-107

17-19/42

 

B-mod 1946-57

5/8" x 1/4" x 90 - 98

18-19/42

 

B-mod 1958-60

5/8" x 3/8" x 97 - 98

19/43

 

Gold Star 1949-57

5/8" x 1/4" x 91 - 98

16-19/42-46

 

Gold Star 1958-63

5/8" x 3/8" x 98

18-19/42

 

M-mod

5/8" x 1/4" x 94 - 98

18-19/42

 

A7 A10 plunger

5/8"x3/8"x 100-102

18-19/42,45,46

 

A7 A10 S/A

5/8"x3/8"x 96-102

19/42

 

Unit models 1959-67

1/2" x 5/16"x 112 - 127

17/45,17-18/47,49,52,60

 

Unit models 1967-73

5/8" x 1/4" x 100 - 108

14-17/47,49,52

 

A50 A65

5/8" x 3/8" x 98 - 110

18-20/42,47


Chain maintenance
Chain play Maximum chain play 1/4" play per 1 foot chain. (6,35mm/30cm) chain play = total play up and down.

Generator

  1/8"  

 

     

Transmission

single

1/2"  

 

duplex pre-unit 1/2"  

 

duplex unit

1/8"  

 

triplex 1/8"  

 

     

Rear chain

rigid/plunger

1/2"  

 

S/A

1 1/4"  
       

 

     

Chain maximum length

Maximum length before replacing your chain.
 

  5/8"

  16 rolls

max length 10 7/32"
 

  1/2"

  23 rolls

max length 11 3/4"
 

  3/8"

  24 rolls

max length 9 3/16"