Readjusting A Conventional Headset; Readjusting An Aheadset - BMW Mountain Bike Enduro Owner's Manual

8.2 Readjusting a conventional Headset.

The adjustment tolerance between there being play in the bearings and
them being set too tight is very small. The bearings are susceptible to
damage. If you want to try it nevertheless, you need two large and flat
open-end wrenches (a).
Release the threaded top nut and tighten the upper threaded bearing
cap a little clockwise. Retighten the top nut.
A too tight adjustment may damage the headset and impair the
performance of the bicycle.

8.3 Readjusting an Aheadset

(*Aheadset is a registered trade mark for threadless systems of DiaCompe)
®
The distinct feature of this system is that the stem does not sit within the
fork steerer tube, but rather slips over the fork steerer tube, which in this
case is threadless (b). The stem is thus an important part of the headset
bearing. Its clamping force secures the bearing in the correct running
position. Instead of special tools you need in most cases only one or two
Allen keys as well as a torque wrench to adjust the Aheadset
the clamping bolt(s) located on the side of the stem by one to two com-
plete turns. Using an Allen key, gently tighten the countersunk adjusting
bolt on top a little, e.g. by a quarter turn (c).
a
.
®
. Release
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b
Do not overtighten the upper bolt, it only serves the purpose of
adjusting the bearing play, not of securing the stem!
Re-align the stem with the frame so that the handlebars are not slanted
when the wheel points straight ahead. Make sure the front wheel is in
line with the top tube and the stem. Tighten the clamping bolts of the
stem (d). Use a torque wrench and never exceed the maximum tighten-
ing torque! You will find the prescribed values in chapter "Recom-
mended Tightening Torques", directly on the components and/or in
the manuals of the component manufacturers.
Bear in mind that by overtightening the bolts the stem can
crush the steerer tube.
Check the headset for play as described above. Take care not to over-
tighten the bearings, as this could easily damage them.
If you do not succeed in adjusting the bearing, this can have
several reasons. If you are in doubt or if you have any questions,
please contact your BMW partner!
Check the secure seat of the stem by taking the front wheel
between your legs and trying to turn the handlebars and stem
relative to the wheel. A loose stem can throw you off your
bicycle.
c
d
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