All available race results Constant de Keyser
| Date | Race | Rank |
| 30/08 | World Championships Road Race (Amateurs) | 27 |
Rider information for 1958
| Rank | 950 |
| Score | 10 |
| Name | Constant DE KEYSER |
| Country | Belgium |
| Team | Individual |
Rider information for 1959
| Rank | 324 |
| Score | 123 |
| Name | Constant DE KEYSER |
| Country | Belgium |
| Team | Groene Leeuw - Sinalco - SAS |
| Date | Race | Rank |
| 03/04 | Ronde van Vlaanderen | 31 |
| 10/04 | Paris - Roubaix | 41 |
| Vuelta a España | ||
| 30/04 | Stage 2 | 70 |
| 01/05 | Stage 3 | 61 |
| 02/05 | Stage 4 | 43 |
| 03/05 | Stage 5 | 44 |
| 04/05 | Stage 6 | 25 |
| 05/05 | Stage 7 | 43 |
| 06/05 | Stage 8 | 11 |
| 07/05 | Stage 9 | 20 |
| 08/05 | Stage 10 | 38 |
| 09/05 | Stage 11 | 38 |
| 10/05 | Stage 12 | 12 |
| 11/05 | Stage 13 | 33 |
| 12/05 | Stage 14 | 32 |
| 13/05 | Stage 15 | 25 |
| 14/05 | Stage 16 | 24 |
| 15/05 | Stage 17a | 9 |
| 15/05 | Stage 17b | 16 |
| General Classification | 24 |
Rider information for 1960
| Rank | 263 |
| Score | 203 |
| Name | Constant DE KEYSER |
| Country | Belgium |
| Team | Groene Leeuw - Sinalco - SAS |
| Date | Race | Rank |
| 05/03 | Ronde van Limburg | 19 |
| 11/03 | Harelbeke - Antwerpen - Harelbeke | 24 |
| 23/04 | Paris - Bruxelles | 58 |
| Vuelta a España | ||
| 26/04 | Stage 1b | 35 |
| 27/04 | Stage 2 | 54 |
| 28/04 | Stage 3 | 34 |
| 29/04 | Stage 4 | 53 |
| 30/04 | Stage 5 | 4 |
| 01/05 | Stage 6 | 8 |
| 02/05 | Stage 7 | 18 |
| 03/05 | Stage 8 | 15 |
| 04/05 | Stage 9 | 9 |
| 05/05 | Stage 10 | 42 |
| 06/05 | Stage 11 | 46 |
| 07/05 | Stage 12 | 57 |
| 08/05 | Stage 13 | 10 |
| 09/05 | Stage 14 | 38 |
| 10/05 | Stage 15 | 48 |
| 11/05 | Stage 16 | 24 |
| General Classification | 31 | |
| Dauphiné Libéré | ||
| 04/06 | General Classification | 38 |
| 01/08 | Scheldeprijs - Schoten | 19 |
Rider information for 1961
| Rank | 256 |
| Score | 213 |
| Name | Constant DE KEYSER |
| Country | Belgium |
| Team | Groene Leeuw - SAS - Sinalco |
| Date | Race | Rank |
| 11/03 | Ronde van Limburg | 39 |
| 01/05 | Grote 1 Mei-Prijs Hoboken | 11 |
| 31/07 | Scheldeprijs - Schoten | 46 |
| 27/08 | Druivenkoers - Overijse | 7 |
Rider information for 1962
| Rank | 339 |
| Score | 119 |
| Name | Constant DE KEYSER |
| Country | Belgium |
| Team | Wiel's - Groene Leeuw |
| Date | Race | Rank |
| 03/03 | Ronde van Limburg | 37 |
| 08/05 | G.P. Jef Scherens - Leuven | 24 |
Rider information for 1963
| Rank | 1165 |
| Score | 0 |
| Name | Constant DE KEYSER |
| Country | Belgium |
| Team | Wiel's - Groene Leeuw |