Typical Tools and Supplies Needed

• Park Repair Stand
• Crown Race Cutter Park CRC-1.
• Measuring Caliper
• Kingsbridge Premium Cutting Oil.
• Degreaser, Citrus or Detergent based
• Paper Towels

This article will discuss the machining of the fork.

See also related articles:

• Visit our Headset 101 page 1 to read about Bicycle Headset Standards and Nomenclature.
• Visit our Headset 101 page 2 to read about Working with Traditional Threaded Headsets.
• Visit our Headset 101 page 3 to read about Working with Threadless Headsets.
• Visit our Tool Use Tips page 1 to read about Reaming and Facing Tips.
• Visit our Tool Use Tips page 3 to read about Fork Column Cutting Tips.
• Visit our Tool Use Tips page 4 to read about Fork Column Star Fangled Nut Tips.

The cutting process can take a long time if the crown race must be resized. As an example, when reducing the JIS standard of 27.1mm fork crown size down to 26.4mm crown race size it is necessary to remove 0.7mm material. The cutter of the CRC-1 uses the inside edge to machine the correct diameter as it passes down the steering column.

The paint on the fork may be used as a marker to track facing. A fresh cut should be seen completely around the crown. Additionally, the cut should be as wide as practical. Fork crown races tend to seat on their outer edge. This crown below shows incomplete facing. Black mark shows a low area, which would cause bearing to seat mis aligned relative to the steering column.

It is necessary to hold the fork while cutting the crown. It is possible to use wood over the jaws of a vise while holding the fork. Alternatively, clamp a front wheel in the fork and stand over the fork while cutting. Protect the tire while cutting with a rag.

1. Determine the correct cutter and install cutter. If in doubt about the size, use a caliper and measure the inside diameter.
2. Install the correct size collet. One-inch forks use the black collet. 1-1/8-inch forks use the blue collet. Leave adjustment collet cap loose.
3. Tighten collet cap to remove play from the CRC-1 body.
4. Lubricate cutting area with CF-1.
5. Turn CRC-1 CLOCKWISE only. Apply downward pressure while turning.
6. Continue to turn until the CRC-1 contacts the crown race seat. Turn 2-3 turns at this point.
7. Loosen collet cap and pull tool upward to check progress. The crown race seat needs to have a fresh cut completely around the fork.
8. Clean fork and clean cutting tool. NOTE: Never use compressed air to clean metal chips.

   NOTE: All cutting tools will eventually require re-sharpening. With use, the cutting edge will dull. While there are many variables that play a role in how long a cutting tool will stay sharp (e.g. technique used, amount and type of lubrication used, type of material being machined, etc.), in general, have the tool re-sharpened once every 50 to 75 cuttings