There have been various bands/artists called ‘Derailleur’. This particular example of the phenomenon appears to be a band from Perth, Western Australia active in about 2000.
The personnel were:
In 2000 they released a CD EP called ‘Spirit of Progress’ with the following track list:
3.Need to Know
4.Bricks & Mortar
I believe that you may be able to buy the CD from Amazon (or possibly from some obscure Australian record store). Support derailleur related music - and keep the flame alive.