fork alignment from the list

From: Andrew R Stewart
To: daniel36911@netscape.net
Sent: Sunday, May 14, 2006 2:04 PM
Subject: How to Align A Fork on the Cheap


Daniel- Forks need to be aligned on three axis's. Side to side, twist
and blade length. I usually do  most of twist then most of the side to
side then most of blade length. Then repeat until all the axis's are
good. For hobby needs a well trued and dished wheel (of the size the
fork uses), a ft. axle cut in half and a small diameter tube are all the
"gauging" tools you'll use.

Clamp steerer in vice. Place the cut axle in the drops. The cones, lock
nuts and axle nuts are in the usual positions on the axle (a solid one,
not QR). When tightened in place the axle sides will align themselves
with the drops' angulation and the axle's cut ends might not align, as
one side points where it's drop's angulation makes it point and the
other side does it's pointing. It is easy to twist each drop to allow
the cut axle ends to align (if you did use a QR axle a sighting down the
axle's inside length would show no misalignment). Next take the small
tube and place it into the drops (having the fork parallel to the ground
with the backside up helps here) and place a rule on the blades right up
next to the crown. Stand in line with the fork and sight along the two,
now, straight surfaces noting any nonparallelness between them. This is
the twist from the crown to the drops. A lever arm placed on either side
of the drops/end of blades will allow bending the two blades so that the
two straight surfaces will be parallel to each other. This will also
average out the differing rake each blade had. Don't worry if one blade
has more curve then the other, the only points that matter for the fork
to be straight are the crown/steerer and the drops. Having corrected
blade twist will recreate a bit of drop to drop nonparallelness. So
repeat the cut axle drop twist alignment and recheck the blade twist
again.

The side to side is the coolest process. take the small tube and wrap
tape around it a few cm from one end. Wrap enough to form a spacer/plug
that fits down into the steerer as it just starts to taper (butt). Wrap
another ring of tape along the tube's length so that this ring is just
inside the steerer's top end and also snug. You have just made a
sighting tube. You can look down it's internal length and "spot" the
steerer's center past the steerer's ends. Place the wheel in the drops,
place the valve hole under the crown so that you can sight down the tube
and through the valve hole. You will see the rim's spoke face near the
label. Make sure that you hold the rim centered between the blades right
up by the crown and see where the sighting tube spots the steerer's
center on the rim's face. (You could mark on the rim's face a center
line or just use an areo rim). Now you can make corrections to the drops
side to side placement, their spacing and the blade length. With this
set up your line of sight is the diameter of the wheel, length of
steerer and a bit of the tube's poking out past the steerer's end.
Rotating the sighting tube in the steerer and repotting the rim's center
corrects for the sighting tube's nonalignment. Side to side and spacing
is simple bending, blade length is done by filing the axle slot deeper.

You'll se that as you do one procedure that it effects the others. I'll
do each a few times slowly reducing the misalignment to a degree that
I'm comfy with. Drop out alignment tools (Campy "H") help quicken things
but really it is the eyes and brain that matter here.

This is how I've done my forks for a long time, with only minor changes.
Now I have a Brignelli fork clamp for my flat surface and when I get it
set up and use it I'll let you all know about it. Andy S.