All-City Cycles Thunderdome Instructions

Thunderdome Fork Instructions
Thanks for buying the Thunderdome Carbon Track Fork. This 1-1/8" aluminum steerer carbon track fork
is designed and intended for use on a Velodrome. When used as intended, we guarantee you'll enjoy
this product.
WARNING: CYCLING CAN BE DANGEROUS. BICYCLE PRODUCTS SHOULD BE INSTALLED AND
SERVICED BY A PROFESSIONAL MECHANIC. NEVER MODIFY YOUR BICYCLE OR ACCESSORIES. READ
AND FOLLOW ALL PRODUCT INSTRUCTIONS AND WARNINGS INCLUDING INFORMATION ON THE
MANUFACTURER'S WEBSITE. INSPECT YOUR BICYCLE BEFORE EVERY RIDE. ALWAYS WEAR A HELMET.
To download full product instructions and safety information go to www.allcitycycles.com
and select the Safety/Tech tab.
1. Stem & Headset Preparation
• Verify that the fork, headset and all required parts for proper assembly have compatible dimensions
The fork, headset, headset spacers and stem steerer clamp must have compatible diameters.
Incorrect use of components can cause component failure.
Visit headsetfitfinder.com to verify fork-to-frame compatibility options. Visit bicycleheadsets.com to learn more
about headset fit and the new Standardized Headset Identification System.
• M ake sure headset parts that come into contact with the steerer tube are free of burrs or sharp edges.
Remove burrs or sharp edges by using very fine grit sandpaper
• M ake sure stem parts that come into contact with the steerer tube are free of burrs or sharp edges.
Remove burrs or sharp edges with very fine grit sandpaper
• O nly use rear slot-style clamping stems. Wedge clamp stem designs must not be used and could result
in failure (Figure 1)

2. Fork Preparation

• Avoid scratching or scoring the steerer tube. Any damage to the steerer tube could cause failure
• A pply a small amount of grease to the crown race seat. Do not make modifications to the crown race seat
of the fork. Only use a headset crown race with the correct inside diameter for your fork steerer tube
Visit headsetfitfinder.com to verify fork to frame compatibility options.
• H old one leg of the fork securely while using a crown race installation tool to install the headset
crown race
Do not place the fork on the dropout tips or crown while installing the race. Doing so can damage
the fork and could cause failure. (Figure 2)
• A ssemble the fork, headset and any spacers in the headtube of the bicycle and install the stem (Figure 3)
• The spacer stack between the headset and stem must not exceed 50mm (Figure 4)
• C arefully measure and mark the amount of steerer tube to be removed. Remember that, when cut,
the top of the steerer tube must be 2–3mm below the top of the headset spacer/stem assembly (Figure 5)
• Remove the fork from the headtube
• Make certain that you do not cut the steerer tube too short—measure twice, cut once
• U sing a new fine tooth hacksaw blade and proper cutting guide, cut the steerer tube. A pipe-cutter
may be used with aluminum steerer tubes
• Using fine grit sand paper, remove burrs and sharp edges
1629 4/13
• Using rubbing alcohol, clean the steerer tube and inside of the stem clamp to remove grease and dirt
• U sing a star-nut setting tool, install the star nut supplied with your headset into the steerer tube per the
headset manufacturer's instructions
NOTE: The Thunderdome fork has an aluminum steerer with an inner diameter (ID) of 24.6mm.
We recommend using a 1" star nut system or a compression plug device that fits this 24.6mm ID.

3. Fork Installation

• A ssemble the fork, headset, headset spacers in the headtube of the bicycle and slide on the stem and
10mm spacer. Insert headset compression adjustment device (compression plug) into steerer and adjust
headset tension using appropriate tool according to the headset manufacturer's instructions. If torque
specifications are not provided, tighten to 1.6Nm (15 in-lb)
• Tighten stem steerer clamp bolts to stem manufacturer's recommended torque specifications
WARNING: Bikes for use on Velodrome should have a fixed gear rear braking mechanism.
For all other street uses, All-City does not recommend riding without front and/or rear braking mechanisms.
Please follow brake manufacturer's instructions.
• Only use the front brake nut supplied with the fork to mount the front brake
• Install the front brake following the brake manufacturer's instructions
1 3
A
B
C
D
Rear steerer slot E
F
2 G
H
I
J
www.allcitycycles.com
A - Compression device or 1" star nut system
B - 10mm spacer
C - Spacers (50mm max)
D - Upper headset
E - Headtube
F - Lower headset
G - Fork crown race
H - Top of steerer tube
I - Fork steerer tube
J - Crown race seat