Tarmac: Fork Cutting and Headset

After the bottom bracket is installed now for the fork sizing and headset installation. This should be very easy because the Allez is very similar in geometry. So this looks like copy-and-paste.

These tools are needed:

  • Bike Stand
  • CSB-1
  • Hacksaw
  • SG-8
  • Vice
  • Tape
  • Knife
  • Respirator
  • Sandpaper (400+)
  • Pen
  • 6mm Allen
  • Torque Wrench
  • Grease

Official Service Manual:

Service/Spare Part:

  • Tange Seiki 1 1/8″ 45°x45°
  • Tange Seiki 1 1/2″ 52x7x45°

Related Post:

Post as guidance? No warranty in ANY case of damage!

First of all the weight check: Fork (not cutted) 347.0g.

The headset bearings are both hybrid ones. At the beginning quite good and no reason to swap. Of course those are IS bearings.

Hybrid means that the race is made from “traditional” steel paired with (in this case) ceramic bearing balls. Silicon nitride balls are also possible.

Before cutting the fork I need to know the right size. Normally this is not as easy as it looks like. In most cases you will start with a larger fork to “find” the right size with spacers. But the allez and the tarmac are at the same dimensions/geometry so I can go with the same spacer combo. Two lower spacers (each at 10mm) and one upper on (5mm) – traditional.

So the pre-assembly is without grease. The marking point is close to the upper spacer. Just make a carve with a cutter.

To get a clean cutting-edge I wrap the fork with some tape and put it in the vice. For the final length we must subtract 4mm because of the steerer tube plug and the ahead cap.

Then its sawing time but do not forget the respirator – carbon dust is more than unhealthy!

To get the final finish on the edge just use some 400 grit sandpaper.

Now for a final dry fit and the assembly of the steerer tube plug.

Never use a star-nut inside a carbon fork, this will damage the fork! Use an expander!

The expander is the original specialized. The function is quite simple. The black cogged expander sits inside the steerer tube. The two inserts are braced between. Because of the conicol caps the cogged spanner will be expanded when the bolt is tightened down.

The specialized expander is direction-bounded – the arrow mark must face the stem. After that just some grease on the bolt an 9NM of torque.

The the last check if the size is correct… excellent.

Now for the final assembly. Grease on the upper an lower bearing cup. Same as the fork cone and the lower bearing.

In the end just insert the upper bearing and put everything together, everything should work smoothly. Finally install the dust cover.

Next step is the assembly of the cockpit… not as easy as it looks like with the Ritchey C260 stem =D