Part 20a
20a.pb) Lead-alloy 'flywheel' | 20a.ni1) Castellated thin gauge nickel-plated steel | 20a.ni2) Castellated thick gauge nickel-plated steel | 20a.ni3) Nickel-plated two-part pulley, nickel plated boss |
20a.bk1) As above, black single-tapped | 20a.ni) As above, nickel with brass boss | 20a.re2) As above, early red | 20a.dr) Dark red |
| 20a.rg Dark red with green rim | 20a.re) Red | 20a.nb) Dark blue | 20a.nb1) Dark blue with blue boss |
20a.re1) Red with black rims | 20a.bk) Black | 20a.bl) Blue | 20a.db) Dark blue |
20a.dy) Dark yellow |
