Altering steering stems for tapered bearings

[Suzsmokeyallan]

So now you have your tapered bearing kit in hand only to find out that your steering stem rebate needs to be lowered for the top tapered bearing to fit down as intended, and you don't have a lathe.
Here's a simple way to do it in your home shop and you will only need a vice, two files and the old ball race from one of the frame cups.
First, mark the spot you need to cut down to and then lay the stem in the vice sideways.
Put the race cup over the stem with the wide side towards the vices side jaws so you can just see your reference mark and keep it there with your free hand against the vice, this race is now your file guide.
Then using a 2nd cut file thats no wider than the section you plan to work on, file your way around the stem, turning the stem as necessary and reusing the race to keep your rebate file line straight.
The race keeps the file from slipping over onto the existing stem section and gives you a near perfect line, therefore you can concentrate on the filing without worry of it ever slipping over.
Once you are close to the overall diameter, switch to a finishing file to 'dress' the cut section to the same diameter as the original upper section.
This whole process takes about 15 to 20 minutes to do if you're proficient with files, and can look almost as good as a lathe job.

[two-stroke-brit]

nice and simple allan.
good advice as allways.