How to eliminate bearing play in the MTB steering system

Stefan Frey

· 19.10.2017

Photo: Georg Grieshaber

How to eliminate bearing play in the MTB steering system

Does it rattle at the front or is the handlebar difficult to turn? Then check whether the headset is correctly positioned. This only takes a few minutes. But a little theory first.

Add bookmark

1 Lower bearing
The bearing shell and bearing are located in the lower part of the head tube. The fork cone (at the bottom) is attached directly to the steerer tube.

2 Upper bearing
A bearing cup and bearing are also located in the upper part of the head tube. The centring or clamping ring is located above this. The headset cover closes the system and usually has one or more seals.

3 Headset claw
The claw is hammered into the steerer tube and expands there. It contains the thread for the preload screw of the cover cap.

4 Cover cap / top cap
The cover cap sits on top of the stem and is screwed to the claw. The bearing tension can be adjusted using the preload screw.

Photo: Georg Grieshaber Headset assembly

Tax rate types

The headset is one of the few components on the bike for which three designs have been established for years and have hardly changed.

External Cup (EC)
The oldest design has bearing shells that are pressed into the top and bottom of the head tube. The bearings are inserted into the shells and lie outside the head tube. Formerly the standard, this design is rarely used today.

Photo: Hersteller External Cup

Zero Stack (ZS)
In the zero-stack design, the bearing shells into which the bearing is inserted are also pressed into the head tube. Here, however, the bearings are located inside the head tube, which reduces the overall height compared to the EC standard.

How do you like this article?

Photo: Hersteller Zero Stack

Integrated Standard (IS)
With the IS standard, the bearing shells are already integrated in the frame. The bearings are inserted directly into the head tube. This saves weight. However, a damaged bearing shell, for example on a carbon frame, can no longer be easily replaced.

Photo: Hersteller Integrated standard

Replacement due?

Like almost all parts on the bike, the headset can wear out over the years. When a replacement is due, the correct dimensions are crucial. Many manufacturers label their headsets according to the S.H.I.S. system. This allows you to quickly find the right model.

Photo: BIKE Magazin

Headset upper part: Firstly, check which of the three headset types is used on your frame (EC, ZS, IS). Then measure the inner diameter at the top of the head tube and the diameter at the top of the steerer tube. Enter the three values into the formula. This makes it easy to identify the right upper part.

Photo: Georg Grieshaber Headset upper part: Firstly, check which of the three headset types is used on your frame (EC, ZS, IS). Then measure the inner diameter at the top of the head tube and the diameter at the top of the steerer tube. Enter the three values into the formula. This makes it easy to identify the right upper part.

Photo: BIKE Magazin

Lower part of the headset: Proceed in the same way at the bottom: Check the headset type, then measure the inner diameter at the lower end of the head tube. Finally, measure the diameter of the steerer tube directly above the fork crown. The lower values may differ from the upper values if the manufacturer selects a mix of different designs, e.g. for a tapered head tube.

Photo: Georg Grieshaber Lower part of the headset: Proceed in the same way at the bottom: Check the headset type, then measure the inner diameter at the lower end of the head tube. Finally, measure the diameter of the steerer tube directly above the fork crown. The lower values may differ from the upper values if the manufacturer selects a mix of different designs, e.g. for a tapered head tube.

Instructions: How to set the headset correctly!

1 Check ease of movement: The handlebars should move smoothly. Lift the front wheel and turn the handlebars back and forth. If it stops moving or turns sluggishly, the preload on the bearing is too tight and needs to be loosened slightly.

2 Check for play: If there is a rattling noise at the front, this is often due to the headset bearing being set too loosely. Pull the front wheel brake and grip the upper or lower bearing shell with your other hand. If you now move the wheel slightly forwards and backwards, you can clearly feel whether the bearing has play.

3 Adjust the play: To adjust the bearing play, you must first loosen the two stem bolts slightly using the Allen key. Then tighten the preload screw at the top of the cover cap until there is no more play or the handlebars can be moved back and forth smoothly.

Tighten the 4 screws: Finally, tighten the two screws on the stem again. Always pay attention to the torque specified on the stem (usually 5 or 6 Newton metres). Also check that the stem is aligned in a straight line with the front wheel.

5 Grease the bearings: The headset is always directly in the line of fire of water, dust and dirt. To keep the bearings running smoothly and cleanly for a long time, you can apply a thick layer of waterproof bearing grease to the bearing shells. Then refit the bearings and wipe off any leaking grease with a cloth.

9 Images

Photo: Georg Grieshaber

You can read this article or the entire issue of BIKE 6/2017 in the BIKE app (iTunes and Google Play) or buy the issue in the DK shop reorder:

Read in the Apple App Store
Read in the Google Play Store
Order in the DK-Shop

Stefan Frey

Editor

Stefan Frey is from Lower Bavaria and loves the mossy, loamy trails of the Bavarian Forest as much as the rugged rock of the Dolomites. For technical descents, he is prepared to tackle almost any ascent - under his own steam. As an accessories specialist, he is the first port of call for questions about equipment and add-on parts, while as head of copywriting he sweeps the language crumbs from the pages of the BIKE print editions.

Home

How to eliminate bearing play in the MTB steering system

Stefan Frey

Most read in category Workshop