| Year | 1989 |
| Date | 06-Oct |
| Volume | 163 |
| Issue | 3,858 |
| Page | 453 |
| Category | Post Bag |
| Part | |
| Title | P.I.V. Drives (Infinitely variable chain drive, D.B. Prof. Chaddock replies) |
| Author | R.G.Bricknell |
| Notes | Managing Director, Positive Infinitely Variable (Transmissions) Ltd. |