Fork
Rechroming
Fork
rechroming will make your bike forks look brand new again
as well as making them functional. Depending on the degree
of existing wear or corrosion the forks will usually
be ground back on a centreless grinder and then chrome
plated
oversize
to allow us to grind the fork back to its original size
and tolerances.
Chrome
Plating: The rechroming process is carried out
in a vat of chromic acid (H2CrO4) where
the forks
will
be plated for
approximately 24 hours.
Process: Hard
Chrome plating is an electrolytic process utilising a
chromic acid-based electrolyte. The
component
requiring plating becomes the cathode and, with the passage
of a DC current via anodes, chromium metal builds on the
component surface. The solution needs to be heated to an
operating temperature between 52 to 58°C.
Hardness: The
hardness of the finished hard chrome plating is in the
region of 950 - 1150HV. Most decorative chrome
plating, the type you might have on your exhaust pipes
is not that hard because it is so thin. Because the actual
layer of chrome on your exhaust is essentially much thinner
than a sheet of paper, when you do a hardness test on it,
the physical strength of that layer is easily broken and
as such the hardness is really the hardness of the underlying
material, steel. However, because the thickness of the
hard chrome plating on your forks is much thicker, the
true hardness of the chrome can be realised. Essentially
its like the difference between the strength of tin foil
and a baked bean tin.
Stopping
Off: Selective Hard Chrome plating using a
masking agent such as clamca wax or stopping-off lacquer
is used
to cover all the internal bushes and valves to prevent
them from interfering with the chemistry of the electrolytic
solution as well as being damaged by it.
Lubricity: One
of the reasons that hard chrome is applied to forks
is because of its inherent lubricity, that is its ability
to slide against other materials when some materials
might seize. This lubricity can be thought of as a marble
table
top that things can easily slide across, whereas other
materials could be seen as a table cloth that bulks and
folds when you try to slide objects over it. That folding
is known as galling and can cause materials to seize.

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