What is the best technique to change an alu fork steerer which is too short for a new frame? Where could I get a new one from? The fork is a Marzocchi Bomber RC3 '09, 1 1/8".

You can't, it's bonded in. You'd have to get a new steerer, crown and stanchion assembly from the importers. Windwave I believe. Or sell the fork and buy one with the right length.

I was thinking about this the other day, there must be a better way of fitting them, ie , threads but then again, who wants a steerer to unscrew…

You can't, it's bonded in. You'd have to get a new steerer, crown and stanchion assembly from the importers.

You obviously weren't here a few years ago for the "kettle of boiling water and curbstone" trick.

Brant, that rings a bell, could you remind the procedure, please?

Essentially, the steerers are press-fit into the crown using some sort of "cryo" process. Cooling by a few degrees K in your freezer isn't anywhere near the change in expansion you can get by increasing the temperature with boiling water.

So – couple of kettles of boiling water over many things (siezed crank arms, or in this case a fork crown), and a bit of a tap, and things come to bits easily.

To install, more hot water, and bang it back in.

Of course non of this is officially recommended 🙂

Windwave will fit new steerers in 'zocchi forks. I have had it done twice. around £40 depending on the type of steerer

Zocchi are not bonded in – they are a press fit.