I have a Mercier Kilo TT that I bought from bikesdirect.com. I like it a whole lot, but I would love to be able to cut the steerer down so that there are no spacers needed. I like to lean real low without raising the saddle so high.
I have read a lot of stuff that gives instructions, but I am worried I am going to ruin something. It looks to me like the thread for the star nut ends around where I want to cut it, so if I do cut it, what will hold the steerer tight? What's inside that dark abyss?

If you're unsure of this you can either have a shop do it, or just put the spacers on top of the stem.

you are correct about making sure the star nut is in far enough... other than that, measure, make a level line in sharpie, put in a vice, hacksaw it off. not much to mess up there.

I'm going to pick up a fork cutting guide.

https://www.pricepoint.com/detail/131...-Saw-Guide.htm

well i am just worried that i will cut the star nut thread altogether and there will be nothing to tighten the steerer with.

Do yourself a favor, leave one or two spacers in case you want to change something in the future, you can put them on top of the stem if you want your bars as low as possible.
The star nut doesn't hold anything together once you have the bearing pre-load set and the stem tightened. If its too high you can carefully drive it down a little further.

If you are going to cut it try using a pipe cutter. It gives a nicer cut and its a bit easier.

1) figure out where you want to cut it
2) figure out where you want the star fangled nut to be (based on where you're cutting it)
3) use whatever jerry rigged tool you used to install the nut to move the nut to where you want it to be (use this and google as a reference if you didn't install it yrself)
4) use a saw (ugh) or a pipe cutter (yay!) to cut the steerer down to the desired length. measure four or five times. remember, you can always cut down more, but once you go too far yr stuck.
i have the ridgid #15 cutter. it's gangster. used it to cut down two chromoly steerers and two aluminum ones. still sharp as hell and has a sharp/strong reamer for cleaning the inside of the cut.
note: not to state the obvious, but if yr reading this from a search and are planning to do the above to a carbon fork, don't. if you want to cut carbon, buy a fine toothed hacksaw and two appropriate sized hose clamps (they make good guides).

"The star nut doesn't hold anything together once you have the bearing pre-load set and the stem tightened. If its too high you can carefully drive it down a little further"
I am confused by this. Not really sure what you mean. The screw's track seems to be welded to the inside so i don't think i can move it. if the star nut is not holding anything down then what makes the drive train lose and tight.
When I loosened the screw, it seemed to loosen up the drive train, i didn't think it had anything to do with the stem.

wat

the star nut is what you screw the stem cap into. this is the first step towards getting your stem tightened and in place.
perhaps he means once the stem bolts are tightened, stress is no longer placed on the star nut...

regardless, you need to tap it down to about 1/2" (no more than this) below where you're going to cut. once that's done, start cutting. the rest will make sense, assuming you've taken apart/re-assembled this bike before.

If everything came loose when you un-did the cap bolt, then it wasn't assembled right. The star fangled nut is a push fit into the steerer and is only used to set and hold the bearing pre-load until the stem bolts are tightened. You can push it down further into the steerer by using some sort of drift and tapping it down with a hammer.
Perhaps you should go to the Park Tool website and search for instructions, then do it right.

wow i don't think i made any sense earlier. i should never type and watch a movie at the same time. i think i understand now though. i thought that the star fangled nut was welded to the inside, but if you all say that it will move then i will give that a shot.

it worked! thanks for the help.

$57.00