Saddle supports

Stayer, or motor-pace, bicycles have some specific parts from the custom geometry to allow a smaller front wheel and reverse rake fork to the large front chainring to provide the gearing to race closely behind a motorcycle. Another addition is the saddle support. Affixed to the top tube and then to the nose of the saddle, it offered support to ensure the saddle did not shift an any direction, especially then the bicycle encountered some steep banks at some velodromes.

Below is a beautiful unrestored early 1930s Malvern Star Stayer bike from my friend's blog. We sold it a couple years ago.  I highly recommend following it if you like old track bikes, and stayers. -
http://vintagetrackbikes-corbettclassics.blogspot.com/

from http://vintagetrackbikes-corbettclassics.blogspot.com/

Here are for different saddle supports. The two bottom examples are manufactured by Cyclo(UK) from the 1940s-1950s. I am unaware who made the other two. They are not for sale.