10
OPI STEM-STEERER
The following procedure should only be completed
by a professional bike mechanic.
Before installation, make sure all part surfaces are
clean. Apply a high-quality bicycle bearing grease
to the surfaces indicated. See shaded areas in
illustration, next page. Make sure both upper and
lower head tube bearings are fully seated in the
headtube.
Follow these steps carefully:
1. Install the upper bearing seal onto the upper
headtube bearing. The open side of the seal
faces the bearing.
2. Position the Lefty onto the headtube by sliding
the Lefty clamps over the head tube and seal.
3. Slide the nylon washer onto the OPI stem with
rounded side facing the shoulder of the stem.
4. Apply grease to fully cover stem bearing
surface and the internal steerer threads. Also
apply grease to the inner race of the upper
and lower headtube bearings. Slide the
desired number of spacers onto the stem. You
may use 0-3 spacers onto the OPI stem. Use
only OPI spacers. See the warning below.
5. Make sure the Lefty is aligned over the head
tube bearings, insert stem (with nylon washer,
and desired spacers) through upper clamp/
seal and onto the bearing. With a soft
mallet, carefully drive stem straight down until
fully seated.
6. Next, install the nylon washer onto steerer
with the rounded side of the washer facing the
steerer bottom flange. Grease entire steerer
lower bearing surface and the steerer threads.
7. Insert steerer into bearing and carefully
hand thread into stem. Do not use a tool.
Continue hand threading until the steerer
contacts the lower clamp surface.
8. Tighten the steerer to 12 Nm using the
Shimano TL-FC33 bottom bracket tool and
a torque wrench. This step draws the stem
and spacer stack to the upper clamp. When
tightened, align the stem and only hand
tighten the upper clamp bolt.
9. Re-tighten the steerer to 12 Nm, ensuring the
stem and Lefty do not move relative to each
other. Then, hand tighten the lower clamp
bolt.
10. Finish by tightening both the upper and lower
Lefty clamp bolts to the final torque of 7 - 9
Nm.
11. Apply Loctite 242 and tighten the handlebar
clamp bolts evenly and equally in a cross
pattern to 6 Nm.
WARNING
USE ONLY 0-3 OPI SPACERS. DO NOT USE
OTHER SPACERS.
Installing extra or different
spacers will result in inadequate thread
engagement between the stem and steerer
resulting in serious damage. A damaged
stem/steerer can break without warning and
you could lose control of your bicycle.
NOTICE
USE A TORQUE WRENCH.
The recommended tightening torque for Lefty
clamp bolts with the OPI stem system is 7 Nm.
Do not exceed 9 Nm.
Over-tightening can damage the OPI steerer
parts .
