I'm going to be trimming down my steer tube. I actually just thought this up on how to tap the star nut down without using an actual star nut tool. What I'm going to do is take the stock one off, remove all these spacers, get a spare bolt and top cap, thread this on a little bit, and I'm going to need to trim off about an inch, so maybe a a sixteenth of an inch below where the top of the stem is.
To tap the star nut down, instead of using the actual tool, use a spare top cap and bolt. Thread it down a little bit and just go little by little, and use this as a guide to keep it straight down as you tap it in. Center it with the top cap and just tap the bolt little by little until you get it to where you want it. Check it periodically just to make sure I don't tap it in too far. I got about another half an inch to go, so just tap it in little by little. As you can see the star nut is tapped down right where it needs to be, went perfectly straight in there, with just using a spare top cap and bolt.
At this point, before I take the stem off and remove the fork, I'm going to make a mark where the top of the stem is on the steer tube. Okay so here's the line where the top of the stem hit. I'm doing that about an 1/8 of an inch below that line. As a guide I'm using a standard hose clamp and I'll be cutting this with a hacksaw. I could also use a pipe cutter.
Here's the finished result, check it out, perfectly straight cut, sanded the edges. Star nut perfectly straight down, doesn't get any better than that. From this point, I'm just going to put the spacers back on and the stem and handlebars, tighten everything back up and we are good to go. Spaces are on there, stem and bars. Put top cap, thread that bad boy in there. Okay here's the finished result, as you can see it looks really clean, took off about an inch off the steer tube. The steer tube is actually stock right now for this bike.