RoadTecAllez

Allez: Fork Cutting And Headset

All the time I raced a long fork with a lot of spacers, I think four?! Reason for this? Because of… I don’t really know… Until today. Time for fork sizing, yeha!

I decided to run a mid-aggressive-style. This means not a total lowered stem. So this time two spacers down, one upper… just to keep the traditional look.

These tools are needed:

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

Service/Spare Part:

  • Cane Creek Forty (ZS) IS42/28.6/H9 Carbon
    • BAA0094UD
  • Enduro Bearings ACB6806 CC (ABEC 3)
    • “(ZS) IS37x49x6,5mm (36°x45º)”
  • Custom Titanium Grade5 Bolt

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

Time to start… I already removed the expander inside the fork. The expander holds the ahead cap which is responsible for the preload of the headset bearing pressure.  The extract of the expander is quite simple: unscrew the inner screw and “hammer it down”. In the end the specialized expander look like this. 

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

To size the fork correctly it is useful to stack all parts together and mark the upper cut. After that subtract  half of the upper spacer so the ahead cap can take its space. Make sure the cap of expander-plug is included in the calculation of the fork length. The final mark for cutting should be done with a knife.

On the allez the stack-formular looks like this: Headset Cap + Spacer (10mm) + Spacer (10mm) + Stem +  Spacer (5mm) – 2,5mm

Because I forgot to take a picture before here is the final one of the whole stack… mea culpa.

To prevent the carbon to fray while cutting the best method is to wrap it with tape. Downside on this you lost your mark, so measure it more than once before cutting =)

For a straight edge a special saw blade is the best. It is also necessary to wear a respirator because the fine dust of the carbon is more than unhealthy. Otherwise happy lung cancer. To complete this step just sand down the edges and your down with sizing.

Time to weight something: 438,8 grams for the sized fork… wonderful.

Now for the new headset combo. Those are the only bearings which will remain as classic steel bearings. reason for this? The benefit of ceramic is the lower friction on high rotation speed. On the headset there is nothing like that so there is no benefit – except of a lighter moneybag… 

The allez has ZS bearings. This means a cup/shell is pressed inside the upper and lower frame which holdes the bearing. Every ZS headset is portable to an IS headset. You just need to know the correct sizing. In a case there is no information available just measure it by yourself =)

The upper bearing is a IS42/28.6/H9 which means an outer diameter of 42mm, inner of 28,7mm and a height of 9mm. The lower is a “specialized special” also found on cervelo bicycles. One reason for this is the integrated crown on the fork itself. The identifier of this bearing is ACB 6808 CC (outer diameter 49mm, inner diameter 37mm, height 6,5mm with cane creek standard (36°x45º)).

The weight of those two bearings are 44,8 grams.

The installation is quite simple: grease inside the cup  and grease on the bearing.

Final step is to insert the fork. The new cane creek headset cap features an integrated compression ring which holds the fork really good. The weight of the new headset top and ahead cap as well as a titan bolt (not original) is 22,7 grams. Next will be the stem and handlebar installation.