Shimano HB-7900 Service Instructions

Note:

• When removing and installing the seal, do it very carefully so
that the seal does not become bent.
When reinstalling the seal, make sure that it is facing the right
way, and insert it as far as it will go.

• Tighten the cone onto the hub axle until it has no looseness.
While aligning the knurls of the cone and the knurls of the
cone holding tube, align section A of the cone holding tube
with section B on the hub axle.

General Safety Information

• Check that the wheels are fastened securely before riding
the bicycle. If the wheels are loose in any way, they may
come off the bicycle and serious injury may result.

• Obtain and read the service instructions carefully prior to
installing the parts. Loose, worn or damaged parts may
cause the bicycle to fall over and serious injury may occur as
a result. We strongly recommend only using genuine
Shimano replacement parts.

• Read these Technical Service Instructions carefully, and
keep them in a safe place for later reference.

Note

• The new 7900 hub is designed so that it will achieve optimal
rotational feel when it is built into a wheel and installed on a
bicycle. The axle rotation will feel heavier prior to lacing into
a wheel. Since the hub is unaffected by the binding pressure
from the quick release, it is unnecessary to allow any play
when adjusting the axle unit.

• If the wheel becomes stiff and difficult to turn, you should
lubricate it with grease.

• Do not apply any lubricant to the inside of the hub, otherwise
the grease will come out.

• Parts are not guaranteed against natural wear or
deterioration resulting from normal use.

• For maximum performance we highly recommend Shimano
lubricants and maintenance products.

• For any questions regarding methods of handling or
adjustment, please contact the place of purchase.

WARNING

Technical Service Instructions

SI-26T0A-003

HB-7900

Note:

The HB-7900 front hub can be disassembled as shown in the
illustration. However, do not disassemble the front hub any further
than this. If it is disassembled any further, it will not be possible to
reassemble it.

OPEN

One Holland, Irvine, California 92618, U.S.A. Phone: [phone] Industrieweg 24, 8071 CT Nunspeet, The Netherlands Phone: [phone] Oimatsu-cho, Sakai-ku, Sakai-shi, Osaka 590-8577, Japan

– To avoid serious injuries:

% First, pull out the hub axle by following the procedure shown

in the illustration. Disassembly from the right side is not
possible.

(2)

Lip is on the outside

Seal

5 mm Allen key

Hub axle

(1)

(3)

Tightening torque:

15 - 17 N·m {130 - 148 in. lbs.}

Disassembly

Cone holding tube

A

Cone

B

Please note: specifications are subject to change for improvement without notice. (English) © Jul. 2008 by Shimano Inc. XBC SZK Printed in Japan.

5 mm Allen key

SI-26T0A-003-00

00