BSA As a direct result of continued research we have developed a new design of bearing for the B.S.A. three wheeler, and because of its unqualified success we have discontinued the manufacture of the original design. It is most important to remember that with this new type the side thrust washers are no longer required and should not be fitted. The bearing Ref. B16G fits all G14 twins from 1932-1940. B16A & B16B are very similar except that they have smaller crankpin tapers. They are fitted to machines prior to 1932, and where required we recommend that customers send patterns to ensure correct identification. Certain B.S.A. C15 and B40 models employ plain type big end bearings and Alpha Bearings reference B21, B23, B24 & B25 relate to suitable roller bearing conversions. Also available is a roller bearing conversion for the timing side plain bearing bush (original part number 40-0389) that is fitted to earlier C15 and B40 machines. The conversions have exactly the original dimensions and no modifications are required. Most notably the timing side roller bearing conversion improves the oil flow to the big end bearing and gives extended service life over the original bush.

70cc & 75cc

Year

Model

Con rod casting No.

Big end Part No.

Cage Part No

Small end Part No.

MAIN BEARINGS

Drive Side

Timing Side

1956-62 Dandy, T/S

64-58

B22

-

SE135

115

LS8

-

1963-65 Beagle

53-71

A10

-

SE220

117

117

115

 

125cc

Year

Model

Con rod casting No.

Big end Part No.

Cage Part No

Small end Part No.

MAIN BEARINGS

Drive Side

Timing Side

1947-53 Bantam, D1

90-253

B20

--

SE24

117

LS8

LS8

1954-57 Bantam, D1

90-497

B20C

--

SE24

117

LS8

LS8

1958-63 Bantam, D1

90-497

B20KS

K59

SE24

117

LS8

LS8

 

150cc & 175cc

Year

Model

Con rod casting No.

Big end Part No.

Cage Part No

Small end Part No.

MAIN BEARINGS

Drive Side

Timing Side

- Two Stroke models

-

-

-

-

-

-

-

1954-59 Bantam Major, D3

90-497

B20M

--

SE24

117

LS8

LS8

1958-64 Bantam Super, D5 D7

90-497

B20KL

K59

SE134

117

LS8

LS8

1958-59 B1 "Sunbeam Scooter"

90-497

B20KL

K59

SE134

117

LS8

LS8

1960-65 B1 "Sunbeam Scooter"

90-1457

B20KT

K59

B910

117

LS8

LS8

1965-66 Bantam D7

90-1457

B20KT

K59

B910

117

LS8

LS8

1967-68 Bantam D10

90-1525

B20KTO

K59

B910

117

LS8

LS8

1969 Bantam D14/4, Bushman

90-1525

B27

K59

B910

117

LS8

LS8

- O.H.V. models

-

-

-

-

-

-

-

1934-36 X34-0, X35-0, X36-0

29-430

B4

-

-

-

-

-

250cc

Year

Model

Con rod casting No.

Big end Part No.

Cage Part No

Small end Part No.

MAIN BEARINGS

Drive Side

Timing Side

- Side Valve models

-

-

-

-

-

-

-

1928-31 B28, B29, B30-3, B31-1

27-1201

B2

-

SE8

-

-

-

27-217

1933-36 B33-1, B34-1, B35-1, B36-1

29-736

B4

K6

SE11

325

65-2052

1937-52 B20, C10. . . . . . . . . . . . . . . . .

65-444

B5

-

SE11

-

-

-

  O.H.V. models

-

-

-

 

-

-

-

1930-32 B1, B2, B3, B4

27-1201

B3

-

SE9

-

-

-

1933 B33-3, Blue Star Junior

29-736

B4

-

SE8

-

-

-

1933-34 B1, B2, B3, B4

29-736

B4

-

SE8

-

-

-

1934 Blue Star, B34-3

29-736

B4

-

SE8

-

-

-

1935-36 B35-2, B36-2, B18

29-736

B4

-

SE8

-

-

-

1935-36 35-3

15-2721

271321

B3

-

SE9

-

-

-

1937-38 B21. . . . . . . . . . . . . . . . .

65-450

B5

K6

SE11

-

-

-

1937-39 B22, Empire Star

65-450

B5

K6

SE11

-

-

-

1939-57 C11, C12

29-2277

B5

-

SE11

325

65-2052

1958-63 C15. . . . . . . . . . . . . . . . .

40-48

B21

K73

SE142

325

40-389 (See Notes)

1959-60 C15S to engine No.C15S 2112

40-48

B21

K73

SE142

325

40-389 (See Notes)

1959-61 C15T to engine No.C15T 1320

40-48

B21

K73

SE142

325

40-389 (See Notes)

1961 C15S to engine No.C15S 3001

40-473

B23

K83

SE142

325

40-389 (See Notes)

1961-64 C15S from No.C15S 3002

41-181S

B24

K84

SE142

325

 

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BSA 350cc to 500cc singles

BSA 500 twins and over