Headset Upgrade

to Tange Japan Headset

Introduction

Although the headset is an important part of the bicycle, it does not really affect your bike’s performance in a big way, especially for a commuter bike like Brompton. (I know, Brompton can be anything from fast road riding to touring bike. But primarily it is designed for commuting.) The original headset is good enough for various tasks. However, my six year old Brompton headset started to rust so I decided to change it. I also found out that the mid range headset Tange from Japan is not that outrageously expensive. These are the two main reasons for this upgrade.

Tools

Naming convention

The upgrading

The verdict

Tools

Bearing cup press

This is a tool that comes in handy to press the new bearing cups into the head stem. Although you can use a wood block and hammer your new bearing cups into the stem, it’s not the most ideal method. I ordered a China made cup press from the web, which was cheap and got the work done. If you can afford it, the Park tool HHP 2 would be the best choice.

Crown race setting system

This is used to knock the crown race (the base for the lower bearing) on to the fork. I thought this was in the set that I ordered, but what I had was actually a cups remover (see next section), which was too small to fit in the fork’s stem! I was temporarily stuck, but figured out a way to get the crown race fixed. By right, I should use a tool like the Park Tool CRS 1.

Cups remover

This is used to knock the old cups in the head stem out. You can use the Park Tool RT 1, but a big flat head screwdriver works just fine too.

Adjustable Spanner

Big enough to hold the 36 mm lock nut.

Cone wrench

A 36 mm cone wrench to hold the top bearing race when you tighten the lock nut.

Hex key and socket

To loosen and tighten the expander cone bolt.

Torque wrench

Able to set for 20 Nm of torque.

Naming convention

The 6 mm hex bolt inside the handlebar column (exposed when the handle bar is folded) is called the expander cone bolt.

The parts of a headset are as shown below:

The upgrading

Step 1

Remove the front brake and front wheel. This is optional but I find it makes the following steps much easier to work on.

Step 2

Use the cone wrench to hold the top bearing race and loosen the steering bearing locknut by approx. 1 turn.

Step 3

Fold the handlebars (not clipped in, though) and undo the expander cone bolt 4 turns and tap it down.

Step 4

Remove the handlebar stem assembly (with the handlebars still folded – to avoid stretching the cables), and put carefully
on one side.

Step 5

Remove the locknut and undo the screwed steering bearing race and withdraw the fork.

Step 6

Take the top bearing out and knock the top and bottom bearing cups out by a cup remover or just use a flat head screwdriver.

Using a screwdriver is more efficient but could cause some scratches on the inside wall of the stem.

Step 7

Remove the lower bearing and knock the crown race from the fork, either by using a special tool like the Park tool CRP 2 or a flat head screwdriver. It is a pain to knock the crown race out by using just one pair of hands, better someone could hold the fork or using whatever cramp or wise to secure the fork.

The special tool is too expensive for an enthusiast like me, as I may use this tool once in my life. But again, the screwdriver could cause some scratches on the stem of the fork.

Step 8

Apply grease in the stem and on the sleeves of the bearing cups. Place the top and bottom bearing cups on the stem and use the bearing cup press to press the cup firmly into the stem. Do make sure that there are no gaps between the stem and the cups.

Step 9

Apply grease on the crown race and the fork where the crown race sits. Use a crown race setting system to knock the crown race into place.

This is where I realised that I don’t have the right tool to set the crown race into its place. I tried using a flat head screwdriver to knock it in but it didn’t really work.

Then I figured out a way to use my bearing cup press and old bottom bearing cup to press the crown race into place.

Make sure the top of the fork will not hit anything before it can compress the crown race completely on to the fork as shown in the following diagram.

Step 10

Clean the fork shaft, apply grease to it and the threads on the top. Put the dust seal on the fork crown race. Then, put the bottom ball bearing over the dust seal with the tapered edge facing up. Put the fork into the head stem. Put the upper bearing on the top bearing cup with the tapered edge down. Put the top bearing race, lock nut washer and the locknut on, and in that order.

1. The gap between the handle bar catcher and the lower bearing cup is narrow and may block the lower bearing. Make sure that the lower bearing goes into the lower bearing cup properly. Take off the catcher if necessary.
2. The lock nut washer has a notch that fits in the grove of the fork stem.

Step 11

Tighten the top bearing race just enough, until you feel resistance. Then, turn it back slightly¹ to ensure free turning movement. Use the cone wrench and the adjustable spanner to secure the lock nut².

1. Some people advise to turn back 90 degrees but I feel that is too much. I suggest to turn it back only 30 degrees.
2. Please make sure that there are no relative movements for the cone wrench and the fork when tightening the lock nut.

Step 12

Clean and put lubricant on the end stem and grease the cone nut at the end of the handlebar stem assembly. Then put the handlebar stem assembly back into the head stem. Slightly tighten the expander cone bolt – not too loose as the handle bar can move without applying force, but not too tight as cannot move any more (even by force, we still need adjustments later on)

Please note where the cables should go when putting the handle bar back. If they are on the wrong side, your handle bar cannot turn as per normal.

Step 13

Adjust the handle bar so that it is 90 degrees to the front wheel. Then tighten the expander cone bolt to 20 Nm.

Step 14

Loosen the handle bar catcher and fully fold the handle bar until it is clipped in. Tighten the catcher again and test if it catches the handle bar properly. Put back the front wheel and front brake.

Step 15

To test the headset, pull the front brake and wriggle the bike to detect headset play. If you feel free play (a tik tok sensation) your headset is too loose and needs to be re-tightened. Do step 3 to loosen the handle bar assembly and leave the handlebar stem up a bit to allow space for your adjustable spanner and cone wrench. Repeat steps 11 to 13 again.

After some riding, do the test again, you may find a bit of free play again. Has to be adjusted again until there is no more free play.

The verdict

Do I feel any difference from before? I don’t really feel any improvement in performance, but visually, it looks much better than my original rusty chrome headset.