In a message dated 12/23/03 2:35:02 PM Pacific Standard Time,
tsan7759142@comcast.net writes:
> As I look at earlier forks I notice they often incorporate a more extreme
> bend very low on the fork than we see in more recent forks and, finally, we
> see the often straight forks (stilettos?) that are seen on, say modern
> Colnagos. The early ones with the extreme bend are more pleasing to my eye. I
> suppose this is just a matter of personal taste.
>
This depends how far back you go. Early forks...say 1940 through the 50s were
made to absorb shock on very bad roads. With the rake almost all at the
bottom of the blade, where it's skinniest, the fork will be more compliant with
road irregularities, particularly if it's a light gauge blade. One of the
advantages of the Reynolds pattern blade was that it was tapered in thickness as it
was drawn, making a relatively thinner blade at the drop out end than other
manufacturers. If you make the blade thick enough, it doesn't matter how much
bend you have, it won't flex (much). Compare that to any number of older French
or British machines with extreme tapers and thin walled fork blades (pencil
stays was a term we used to use for these "frail" frames). You can push down on
the bars and see the blade flex near the tip. Very comfortable on rotten roads,
not stiff on smooth roads. If you built a straight bladed fork out of the
exact same (pencil) tubing, you would get LESS deflection at the tip because you
wouldn't have the angle allowing as much movement.
I saw one old Raleigh fork that must have had 4" of rake with all the bend in
the bottom third or fourth of the blade. With the wheel pushing straight up
on that, it has a lot of leverage to move the fork blade in the direction of
what amounts to "suspension travel".
The extreme illustrates the principle.
Stevan Thomas
Alameda, CA