The introduction of the straight-blade fork is an important moment in the history of Colnago’s bike production. It was a turning point that led the entire cycling industry into a new era. The Precisa straight leg fork first appears in their 1989 catalog, but is still manufactured today and supplied with modern Colnago Master and Arabesque steel frames.
A Revolution in Bicycle Fork Design.
The following information is an extract from the Colnago website.
Strokes of genius are unpredictable, and the history of the Precisa fork is similar. In 1988, the forks fitted to the bikes Ernesto Colnago has designed have curved blades. This is the tradition at the time, and it’s an established fact that no one manufacturer had ever thought to change. They’re good, they look perfect, they are light, and they do not have significant defects. Yet, the intuition comes from a discussion with the “Drake”, Enzo Ferrari, another pioneer of the twentieth century. From concept, through tests and trials, until finalization, it’s a short step. The discovery is revolutionary. A fork with straight blades can guarantee exceptional results, far superior to forks with curved blades. The results of the tests conducted by the engineers at Ferrari speak for themselves. Vibration absorption is maximized (also benefitting the integrity of the headset), the danger of resonance by vibrations transmitted from uneven surfaces is controlled, and better comfort and handling precision is achieved. Simply put, a frame with a straight fork is much easier to control, and is more safe and stable – a success! From that moment on, the Precisa fork, renamed by Ernesto Colnago, supplanted the classic style and the entire cycling industry adapted the new design.
Straight Leg Fork vs. Curved Leg Fork
According to tests conducted by Ferrari and Colnago, the straight leg fork has the following advantages;
- Better vibration absorption for improved comfort.
- Better stability.
- More precise handling.
That leaves just the aesthetic difference. If you’re after a pre-1990’s vintage aesthetic for your bike, then fit a fork with curved legs, otherwise the Colnago Precisa fork was better in every way to a traditional curved leg fork.
Precisa Fork Design Variations
I don’t know how many design changes have been made to this fork over time, but I have identified 3 different variations of the fork crown markings of the Precisa fork.
The first version of the Colnago Precisa fork featured the same fork crown markings as the curved forks of the late 1980’s. It also features a 1 inch threaded steerer tube to suit the threaded headsets which were still found on road bikes up until the late 1990’s.
Here is another version of the Colnago Precisa fork which first appeared on the Colnago C40 in the 1995 Colnago catalog. You can see it has a more decorative 3 point crown.
In 1996, looking at the Colnago catalogs, the stamping on the fork crown changed to the current style. Which features the Club symbol with the letters ‘COLNAGO’ below. At some point the fork incorporated a non-threaded steerer tube, but the steerer tube has remained a 1 inch diameter.
Differences in Fork Rake?
The change from traditional curved legs to straight legs naturally affects the rake of the fork, which in turn changes the steering response of the bicycle.
To ensure the new Precisa fork retained the same rake as the traditional curved fork, the Precisa fork crown was designed to ANGLE the steerer tube to match the fork rake measurement of curved forks (which according to my research is 43mm).
The image below shows how the fork steerer is angled up and not directly inline with the legs of the fork. When fitted to the bike, the angle of the steerer tube causes the legs to sit forward of the head tube positioning the drop-outs in the same spot as the traditional curved forks.
Note: Steering response is also affected by the head tube angle which often varies by frame size, however changing from traditional curved forks to Precisa forks on a specific frame should have no affect on the steering as the fork rake is the same and the head tube angle hasn’t changed.
Precisa Fork Components & Quality Control
I have been riding and working on my own bikes for many years now. I wanted to share my experiences, knowledge and research with others. My aim is to inspire people to get involved in all aspects of this amazing sport. Cheers.
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