extending forks........?

my forks have threaded tops where the cap threads into it to hold the handlebars.

did anyone ever make (or have available for sale) something to extend the fork length ?

Like an aluminum cylinder, threaded at one end (to go into the fork) and then about 4 or 5cm long that the top clamp can bite onto..

long shot but....:dry:

i think they did back in the 70's. but they are one of the most dangerous modifications i think you could make. lotsa stories about forks snapping and stuff. extended tubes would be the safest route.