How to adjust the headset?
Can't get rid of that little bit of slack in the steering? Do you feel a small resistance when turning the handlebar? The symptoms are clear, your steering bearings can't take it anymore! If the integrated bearings are very simple to maintain and replace, the thing becomes more difficult as soon as we talk about bearings with cups.
Before we start, here is some of the vocabulary you will need.
Like the bottom bracket, the headset is an interface that ensures compatibility between the fork and the frame. And as with the bottom bracket, bike brands do not hesitate to modify their standards to offer us more and more rigidity or to reduce the weight of our precious frames. Welcome to the jungle of bearing standards!
The headset is characterized by the type of cups used together with the dimensions of the bearings. Some frame manufacturers use 2 different types of cups between the top and bottom of the headset (external at the bottom and semi-integrated at the top). The top and bottom of the headset must therefore be characterised independently.
In addition, there are standard fork steerers with different diameters: 1" (disappearing), 1"1/8, 1"1/5 or conical 1"1/8 top / 1"1/5 bottom.
In order to be able to assemble any fork on any frame, component manufacturers now offer a multitude of products, and even sell the top and bottom cups separately to satisfy the most exotic set-ups. At the same time, they have developed a direction sets codification system that covers all standards. It is called the SHIS: for Standardized Headset Identification System.
A complete headset is therefore characterised by an upper SHIS and a lower SHIS.
The first 2 letters of a SHIS code correspond to the type of cups. The first number corresponds to the inner diameter of the headset et le and the second is the outer diameter of the fork steerer tube.
1/ Required equipment
Required Tools:
- Workshop stand
- Headset cup remover
- Hub Bearing Press
- Cone Remover (depending on your type of cone)
- Cone Shrinker (depending on your type of cone)
- Lithium grease
- Straps
- BTR Wrench
- Mallet
2/ Identify the type of cups
- The EC type for "External Cups". The bearings are located in a cup on the outside of the frame.
- The ZS type for "Zero Stack" or semi-integrated. The bearings are located in a cup pressed into the frame.
- The IS type for "Integrated System". The bearings are inserted directly into the frame without any cups.
IS frame connectors are very easy to identify because of the special machining that allows the bearings to be accommodated directly without cups (see picture 02-1).
However, EC and ZS bushes are very similar. The only thing that distinguishes them is the headset that is fitted as standard: an EC type headset will have a high cup height on the outside of the frame whereas a ZS type headset will only have a low cup thickness on the outside of the frame (1-2 mm, see picture 02-3).
To avoid errors when purchasing the headset, we recommend measuring the top and bottom inner diameters of the head tube as well as the top and bottom diameters of the steerer tube to make up the SHIS codes (see figure 02-4).
3/ Fork removal
In order to work in good conditions, remove everything that connects the fork to the cockpit:
- Brake caliper and any brake cable guides.
- Secure the fork to the frame with a strap or clamp.
- Unscrew the headset cap completely.
- Unscrew the stem.
- Secure the cockpit to the frame with a strap, taking care to protect the frame.
- Remove the fork.
4/ Removal of bearings
Insert the cup remover into the steering sleeve until the claws pass under the cups. Then tap on the other end of the cup remover with a mallet until the cup is removed. Repeat the operation on the other side of the head tube.
5/ Inspection of cups spans
6/ Fork cone replacement
The fork cone is the small ring at the bottom of the fork steerer tube. It acts as the inner bearing seat for the bottom bearing of the headset. If it is damaged or different from your new headset, it should be replaced.
The fork cone is pressed onto the steerer tube, so it has to be removed, and there is a relatively expensive tool for this: acone puller (from 250 to 450€). t is therefore best to contact a bicycle professional for this operation. However, fork manufacturers have added a notch in the fork crown to allow the use of a flathead screwdriver to pry the fork out.
Once the cone is disengaged on one side, repeat the operation on the other side of the pivot.
Be careful not to mark the fork crown during this operation.
Insert the new fork cone using the fork cone insert.
Note: Note that for this tutorial we used a headset to mount a straight fork in a tapered head tube.
7/ Reassembly
- Apply a thin layer of lithium mechanical grease to the contact surfaces.
- Then press each bearing one by one (this way it will be easier to position them in the axis).
- Apply a thin layer of grease to the bearing seats.
- Then reassemble the whole set, respecting the initial position of each part.
8/ Settings
After reassembling, check the centering of the caliper on the disc and adjust if necessary. Check the play in the steering and adjust if necessary.
