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| English
English |
S -
69
The Headset
The headset connects fork, stem, handlebar and front wheel to the frame, but
allows them to turn freely as a unit. It must turn with virtually no resistance, if the
bicycle is to run straight, stabilising itself as it travels. Shocks caused by uneven
road surfaces expose the headset to considerable levels of stress. As a result it
may become loose and maladjusted.
Checking the Bearing Play
• Check the headset for play by placing your fingers around the upper head cup.
• Pull the front brakes with your other hand and push the STEVENS bicycle firmly
back and forth with the wheel remaining on the ground.
• If there is play in the bearing, the upper head cap will move noticeably relative
to the lower cup and you will feel a jerk.
• Another way to check the headset is to lift the front wheel a little off the ground
and then let it drop. If there is play in the bearing, you will hear a rattling noise
in this area.
• To check the bearing for ease of running, lift the frame until the front wheel no
longer touches the ground. Move the handlebar from the left to the right. The
front wheel should turn very easily from far left to far right and back without
catching anywhere. A light tap on the handlebar should be enough to turn the
wheel to the side.
Danger:
Riding the bike with a
loose headset increases
the stress on fork and
bearing. This can result
in fork breakage with
severe consequences!
Adjusting the Threadless Headset: Aheadset
®
Headsets
The special feature of this system is that the stem is not encased by, but rather
clamped onto the steerer tube, which in this case is threadless. The stem is an
important part of the headset bearings. Its clamping force secures the bearing in
its set position.
Some frames are delivered with the headset partly integrated in the head tube.
The headset is then no longer visible. There is a seamless transition of spacer and
the fork into the head tube. The adjustment of the bearing is the same as with
the usual Aheadset
®
headset. But in this case you check the bearing play in the
transition area of frame and fork.
• Release the clamping bolt(s) located on the side of the stem by one to two
complete turns.
• Gently tighten a little the countersunk adjusting bolt on the top, i.e. by a quarter
turn at the most, by using an Allen key.
• Realign the stem with the frame so that the handlebar is not slanted when the
wheel points straight ahead.
• Retighten a little the clamping bolt(s) of the stem until the stem no longer turns
relative to the fork. Do not exceed the torque values specified by the stem
manufacturer, see the chapter
“Recommended Torque Settings”
.
• Check the headset for play, as described above. Do not overtighten the head-
set. Risk of headset failure.
Caution:
Do not overtighten the upper bolt, it only serves the purpose of adjusting
the bearing play, not of securing the stem!
Caution:
In the case of full carbon forks the torque values are often clearly below
the specifications of the stem manufacturers. A sufficient clamping is usu-
ally already achieved with inferior forces. Tighten carefully by approaching
the prescribed maximum torque value in small steps until the stem no
longer turns relative to the fork or front wheel. Too high torque values can
destroy the steerer tube!
Caution:
These adjustments
require specialist
knowledge, experience,
suitable tools and
a certain amount of
manual skills and should
therefore only be carried
out by professionals.
Contact your STEVENS
dealer.
Danger:
Check the secure seat
of the stem after having
adjusted the bearings,
by holding the front
wheel between your
knees and trying to twist
the handlebar relative to
the front wheel. A loose
stem can throw you off
your bicycle
