Hammerschmidt TRUVATIV User manual

PLEASE READ THE SAFETY AND WARRANTY INFORMATION INSIDE
95-6115-004-000 Rev A Copyright © SRAM Corporation, 2008
User Manual

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INTRODUCTION
Your days of front shifting as you know it are over. Welcome to instant front transmission. Welcome to HammerSchmidt!
HammerSchmidt is a front transmission so fast and so seamless it’s magical. It gives you the security of a single chainring,
with the gear range of a double. HammerSchmidt provides better ground clearance and awless shifting: shifting under
load, while coasting, or even standing still. This revolutionary instant shift is accomplished with the proprietary
HammerSchmidt X.0 and X.9 trigger shifters. HammerSchmidt’s front transmission design is comprised of ve main
components: HammerSchmidt bottom bracket, crank arm, collar assembly, mechanism assembly and trigger shifters, each
working in perfect concert, allowing you to react to terrain in ways you’ve never imagined before. Take a peek below at the
anatomy of HammerSchmidt.
ANATOMY OF THE HAMMERSCHMIDT UNIT
TOOLS NEEDED
• Safety glasses • Bottom bracket facing tool and cutter
• HammerSchmidt frame compatibility checker (Schmidty recommends Park Tool BFS-1)
• 2, 2.5, 4, 5, and 8 mm hex wrenches • HammerSchmidt ISCG tab facing cutter
• Flathead screwdriver • Cutting Oil
• Cable cutters • Truvativ ISIS and GXP bottom bracket installation tools
• Adjustable torque wrench up to 54 N·m (478 in-lb) • Grease
• Digital calipers
FRAME COMPATIBILITY CHECK
HammerSchmidt is engineered to mount to frames with ISCG 03 or ISCG 05 chain guide mounting tabs and 68, 73,
or 83 mm bottom bracket shell widths. However, not all frames are made to the precision standards HammerSchmidt
requires. Therefore, before installing you will need to perform a simple frame compatibility check to determine if you can
use HammerSchmidt on your frame. It is critical to perform this check, otherwise you will experience complica-
tions with installation and/or function.
To check compatibility, use the enclosed HammerSchmidt frame compatibility checker tool. First, remove your old crank arms
and bottom bracket from your frame (if applicable). Next, thread the cup checker into the drive-side bottom bracket shell.
Finally, slide the pin checker over the cup checker and insert the pins into the ISCG tabs. The pin checker is double sided; one
side has ISCG 03 pins, the other ISCG 05 pins. Be sure to insert the appropriate pins into the ISCG holes. For compatibility,
the pins must go into the ISCG holes, the cup checker must be centered in the pin checker and the arrow on the pin checker
should point toward the rear wheel axle. If the tool is difcult to insert, won’t t at all, or the arrow doesn’t point toward the rear
wheel axle, you cannot use HammerSchmidt on your frame.
If you need additional help to determine the compatibility of HammerSchmidt you can visit www.magicmechanics.com or head
over to your local Truvativ dealer for assistance.
COMPONENT COMPATIBILITY
• Bottom Bracket - HammerSchmidt BB only
• Front Shifter - HammerSchmidt X.0 and X.9 trigger shifters only
• Chainrings - HammerSchmidt 22 or 24 tooth
• Chains - 1 x 1, 7, 8, and 9-speed SRAM®or Shimano®chains
NON-COMPATIBILITY
Do not mount HammerSchmidt to an ISCG adapter device. ISCG adapters do not provide enough structural integrity to
handle the weight and loads applied by HammerSchmidt. ISCG adapters are only intended as a means to mount chain
guide devices to non-ISCG frames; make sure you keep it that way.
HammerSchmidt Bottom Bracket
Collar Assembly
HammerSchmidt Mechanism Assembly
with Drive Side Crank Arm
HammerSchmidt Trigger Shifters
HammerSchmidt Non-Drive Side Crank Arm
Chain Guide

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FRAME PREPARATION - PART II
Ok, are you ready for the nal and most critical step in frame preparation?
Step 4. Replace the bottom bracket facing cutter on your tool with the Truvativ ISCG tab facing cutter that is appropriate for
your size ISCG tabs and remove all spacers from the cutter.
• If your ISCG tabs are ush with the face of the bottom bracket shell (zero offset), you will only be facing the tabs to
ensure they are parallel to the bottom bracket shell face. Face the ISCG tabs using the same method provided by
the manufacturer of your bottom bracket facing tool. If the cutter does not completely face the surface of each tab,
add a 0.5 mm spacer to the cutter tool and face again. When you are nished facing, be sure the ISCG tab surface
is smooth and free from burrs and debris.
Note: if you added a 0.5 mm spacer to the cutter, you now have a 0.5 mm offset to your tabs. Write this number
down, you will need it later.
• If your ISCG tabs are offset inboard of the face of the bottom bracket shell, you will need to determine that offset
prior to facing so you can space the cutter tool to match. Use the depth stick on the caliper and measure the depth
at all three tabs. Select the largest of the three numbers and write it down, this is your offset.
IMPORTANT
The following sections on Frame Preparation call for making permanent and non-reversible modications to your frame,
requiring advanced mechanical knowledge, skills, and tools. We recommend these procedures only be performed by a
qualied bicycle mechanic. If you choose to perform these procedures yourself you should read and understand these
instructions and have a working knowledge of tools required prior to starting work on your frame. In addition, you should
wear your safety glasses until you have completed all the steps in this manual.
FRAME PREPARATION - PART I
Now that you have determined that the ISCG tabs on your frame are compatible with HammerSchmidt, it is time to make
sure the face of the bottom bracket shell and ISCG mounting surfaces are parallel and uniform. This is a critical process
because one part of the HammerSchmidt mechanism is located off the bottom bracket shell while the other part is located
off the ISCG tabs. When they are mated together, the HammerSchmidt internals need to be aligned so they can engage
and function properly. Let’s get started:
Step 1. Make sure your frame’s bottom bracket shell threads are clean and undamaged; there should be no paint or dirt in
there. For best results, have your bottom bracket shell tapped by a professional bicycle mechanic.
Step 2. Measure your bottom bracket shell width with a pair of digital calipers. The shell width should be either 68, 73 or
83 mm (+0.3 / -0.2 mm).
Step 3. Face the bottom bracket shell. This will create a at surface for ISCG cutter to bottom out on in the next step. Keep
in mind the tolerances as you face the bottom bracket shell. If the shell width exceeds the maximum tolerance value
(+0.3 mm), you will need to face it within specication. However, do not face shorter than the minimum tolerance
value allows (-0.2 mm). Follow the instructions provided by the manufacturer of your bottom bracket facing tool for
proper operation of the tool.
68, 73, or 83 mm Offset
Flush

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FRAME PREPARATION - PART II (CONT)
Locate your offset in the chart below and select the spacer or combination of spacers from those supplied with the Truvativ
ISCG cutter. The cutter comes with 0.5 mm, 1 mm, and 2 mm width spacers, each marked with its width. For 68 mm width
bottom brackets, do not exceed 0.5 mm of cutter tool spacing. For 73 mm and 83 mm width bottom brackets, do not exceed
3.0 mm of cutter tool spacing.
OFFSET (mm) ISCG CUTTER SPACER(S) REQUIRED*
0.0 None
0.1 - 0.5 0.5 mm
0.6 - 1.0 1.0 mm
1.1 - 1.5 1.5 mm
1.6 - 2.0 2.0 mm
2.1 - 2.5 2.5 mm
2.6 - 3.0 3.0 mm†
*write this number down you will need it again later on
† maximum spacer value for 73 and 83 mm bottom brackets
Face the ISCG tabs using the same method provided by the manufacturer of your bottom bracket facing tool. If the cutter
does not completely face the surface of each tab, add a 0.5 mm spacer to the cutter tool and face again. Remember, do
not exceed 3.0 mm of spacers. When you are nished facing, be sure the ISCG tab surface is smooth and free from burrs
and debris.
Caution: for 73 and 83 mm bottom brackets do not exceed 3.0 mm of spacers during facing. If you exceed
3.0 mm of spacers the resulting offset will be too large and the custom HammerSchmidt mounting bolts will not have
enough thread engagement with ISCG tabs to safely mount HammerSchmidt.
GREASE IT UP
Apply a liberal amount of grease to the bottom bracket shell threads in the frame. If you haven’t already, pull the non-drive
side cup off the bottom bracket and apply a small amount of grease to the cup threads. Carefully separate the center shell
from the drive side cup and apply a small amount of grease to the o-rings on each side of the cup. Insert the center shell
back into the drive side cup. Finally, apply a small amount of grease to the drive side cup threads.
SIZE IT UP - 68 MM BOTTOM BRACKETS ONLY
If you have a 68 mm bottom bracket shell, separate the two parts of the bottom bracket and install the included bottom
bracket spacers, one over the drive side bottom bracket cup, the other over the non-drive side bottom bracket up. This will
set the bottom bracket spacing to accommodate HammerSchmidt.
HAMMERSCHMIDT™ INSTALLATION
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INSTALL HAMMERSCHMIDT BOTTOM BRACKET
The HammerSchmidt bottom bracket needs to be installed in a specic order:
A. Thread the drive side bottom bracket assembly into your frame using the Truvativ ISIS (or equivalent) bottom bracket
installation tool. The drive side assembly is left-hand threaded, so turn it counter-clockwise to install and torque to
34-41 N·m (301-363 in-lb).
B. Install the non-drive side bottom bracket assembly using the Truvativ GXP (or equivalent) bottom bracket installation
tool. The non-drive side assembly is right-hand threaded, so turn it clockwise to install and torque to
34-41 N·m (301-363 in-lb).
CHAINRING CHANGE UP - OPTIONAL
If you want to change your chainring size, now is a convenient time to do it. Locate the retaining ring on the
HammerSchmidt mechanism crank arm and use a athead screwdriver to gently pry the retaining ring off the ring guide.
Remove the ring guide and chainring. Install your other chainring. Re-install the ring guide and carefully press on the retain-
ing ring using the athead screwdriver. Make sure the retaining ring is fully seated in the groove of the ring guide by rotating
it a couple of revolutions.
INSTALL THE COLLAR ASSEMBLY - PART I
A. Get Your Disk on
Check that the seal disk for your frame’s ISCG standard (ISCG 03 or ISCG 05) is installed. If you need to change out
the seal disk, use a 4 mm hex to remove the cable anchor bolt and a 2 mm hex to remove the seal disk retaining bolt
then switch seal disks. Make sure the recess on the seal disk anchor bolt window faces down. Re-install the cable
anchor bolt until it is hand tight. Re-install the seal disk retaining bolt and torque to 0.5 N·m (4 in-lb).
B. To Space or Not to Space?
The collar assembly must sit ush with the bottom bracket shell face (or spacer for 68 mm bottom brackets). So now you
need to determine if you need to add ISCG tab spacers.
If your frame’s ISCG tabs are ush with the bottom bracket shell face, you do not need to add any spacers. If your frame’s
ISCG tabs are offset inboard of the bottom bracket shell face, you will need to add the same amount of spacers you used
when facing the ISCG tabs in the Frame Preparation section in order to make the surface ush (you wrote this down
remember?). Locate the ISCG specic spacer(s) you need.
68 mm bottom bracket users! You must add an additional 2.5 mm of spacer thickness to the ISCG spacers you needed
above. This will complete the spacing requirements necessary for HammerSchmidt.
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34-41 N·m (301-363 in-lb)