I love unusual, obsolete and before-their-time bike components, especially 80's/90's performance parts.
The other day I managed to get my hands on one oft sought after track groupset, the Dura Ace 10 pitch group from the 1980's. The difference between this and other track groupsets is that the pitch (distance between chainring teeth) is only 10mm, tiny in comparison to the usual pitch, the reasoning behind this tiny pitch is that it makes the whole groupset smaller, hence saving weight.
Now I don't expect to win gold medals on the track now simply because I am using this archaic technology but I love the striving for performance that leads someone to design something like this!
Here is a comparison between the DA 10 sprocket on top and the normal pitch DA sprocket on the bottom, both are 15 tooth. When weighed on my crappy kitchen scales the regular sprocket comes out at 40g and the DA 10 at 25g! so there must be some logic to the performance enhancing capabilities of this groupset, even if it does save about as much weight as chopping off the end of your finger, or taking a dump before a race...