Restoring a Sakae quill stem - 4 easy steps for polishing steel to mirror finish

Table of Contents

In this article I’m going to give you a number of tips for polishing steel to mirror finish. In this case the subject is a Sakae quill stem from my late seventies Bridgestone Submariner.

But before we can even start with the polishing we first needed to remove the stem. And that turned out to be a lot harder than I wanted it to be.

For the most extensive article on metal polishing read the article how to mirror polish a crankset.

Video Tutorial

Step 1. Removing the stem

The Sakae quill stem was seized into the frame, so it needed a little encouragement before becoming loose. A tap on the binder bolt will loosen the wedge, which is the part that’s always rusted inside the frame and keeps it there.

In my case the inside of the frame itself was also corroded against the stem. So a couple of firm taps on the stem itself with a mallet made sure it moved inside the frame.

It turned out a washer on top of headset was rotated onto the threads because of the bolt on top of it and needed to be pried off before the stem could be removed.

By turning the headset I created a little wiggle room for me to put a screwdriver in between the headset and the washer.

Finally the thing came off.

The stem sits on Sakae Custom Road Champion handlebars with Dia Compe brake levers. I already know that when fully restored, they will look absolutely stunning. But for now they’ll need to go off. And the torn handlebar tape as well of course.

Step 2. Removing rust

Before I can start polishing the thing the rust will need to be removed. I use a diluted HG roestoplosser for this.

Step 3. Sanding

With a cleaned Sakae quill stem you can start the sanding step. Each consecutive step increases the grit-count.

I start with a 60-grit count, which is extremely coarse, so I’m able to remove the scratches and nicks. The steps after that are used to create an even surface for the polishing machine to work with.

A finished sanding process will leave a smooth but dull finish

If you like a dull instead of a shiny finish you need to go up to a 4000 grit sandpaper and stop there.

I’m going for a mirror-finish, so the steps I took with the sandpaper were 60, 150, 220 normal sanding. And 400, 600, 800, 1000, and 1200 wet-sanding.

And yes, it takes a lot of time to finish all of these steps.

Step 4. Machine polishing steel to mirror finish

I don’t have any more pictures of the machine polishing step because the battery of my camera gave up. It was freezing outside while I worked on the stem and I didn’t notice the camera wasn’t working until I finished the job.

Machine polishing is pretty straightforward however. The machine polisher has to wheels, a coarse and less coarse one.

The yellow coarse one is for cutting the metal. And you need a different cutting compounds to do so.

The white less coarse wheel is for actual polishing. All in all I use 4 different compounds

I started using a face mask normally used during spray-painting, when I started noticing my entire face got covered in the stuff coming off the wheels.

The final result should look something like this.

And that’s how you polish a Sakae quill stem to a mirror finish! If you like this article give it a thumbs up. If you have any questions or suggestions for new articles, let me know in the comments below. Cheers.