There are many instances of racers also building bikes. I believe there are examples of builders who turned to racing, racer/builders who handled both tasks concurrently and racers who turned into builders. I believe the last category is the most common.
A very quick sampling from Italy where the ex-racer was intimately involved with production is: Basso, Benotto, Cimatti, Cinelli, Dei, Fondriest, Gerbi, Guerra, Masi, Moser, Olmo, Pinarello... To the best of my knowledge, none of these bike brands were "rented" names as stated by Jan in an earlier post.
Perhaps I am oversimplifying, but it would appear that the lower the quality the bike carrying a former pro's name, the greater the likelihood that the name is "rented".
Steven Maasland
Moorestown, NJ
USA