The Chopper Compendium

Hi guys,
I was planning about using some SKF bearings with an internal hole of 25mm (1") for my bike (I've already have them) and place them on an accordingly dimensioned steering stem turned in the lathe from a mild steel 25mm bar, threaded in the upper portion to an M24x3mm to accept the jam nut and the steering nut.
This was the original plan, but then I thought that maybe I could save some work if I just bought a 24mm threaded bar (maybe 10.9, so that I will be quite sure that it's strong enough for the task..), screw and weld it into the tapped lower yoke, and sleeve & plug weld it with a bushing of 25mm OD (and obviously 24mm ID) for the remaining part, except for the final part, where I will need the threads once again. Something like what it's often done to build a girder's shaft, I mean.
What do you think, is the sleeve going to be a little bit too thin? (it will end up having a wall thickness of 0.5mm, which, btw, is about 0.02"...)
At the end it 's there just to "thicken" up the threaded bar up to the right size to have an interference fit with the lower bearing, and I don't think it will deform while I press/hammer it in, because there's always the threaded bar inside... right?

#1, I would not do this for a steering stem. You would probably wind up crushing the thin sleeve and threads on the bar, (if not when you press it together, over a short period from stress). It doesn't take much for steering to make an ill handling bike. Another note, no matter what the material is, when you weld it it changes the properties of the material. Make or have a stem made from 1018 cold roll. Guess there is no #2!
Just my $.02

I ended up doing just like you suggested..
Many thanks