Yes.... Those ones were made by my good friend Dave Crampton.
They do actually serve a purpose..... mike... I think I may have said they were less of use on the road?
For track use, where the bike sliding down the track is fairly likely at some point, they help save the forks as Ric has shown, and also potentially expensive dampers like the BGM's too.
Those particular crash bobbins were a joint design between myself and Dave. Dave sized up and made the main one..... it is used in conjunction with a longer stainless pivot bolt. The material is an extremely hard substance with really good sliding and wear properties! ( The roller skate buffers are designed to actually grip (!) so will likely cause more damage by effectively making the forks dig in? )
if you look carefully at the top damper mounting there is a second small bobbin. This is more relevant on a special class or cut down. It is designed to let the top bobbin hit the surface first if its not protected by legshields etc.
The bobbins are made to order and made on a cnc machine..... so are very high quality due to the material used...... so not the cheapest things in the world!