In the early 1980’s Colnago began experimenting with crimping main frame tubes to increase stiffness. Colnago referred to these crimps as ‘ribs’ in their early brochures. In 1988 Colnago released the Colnago Conic SLX Total Spiral bicycle which featured a unique crimped down tube which increased in diameter as it reached the bottom bracket in a similar way modern framesets are designed.
Whilst the early model of the Colnago Conic SLX Total Spiral was shown in the catalogue with traditional curved forks, later models were shown with the new Colnago Precisa straight leg steel fork. The Precisa fork was another of Colnago’s many innovations in the bicycle industry and this design improved ride quality over traditional curved forks.
Before you start with the identification process, you should start here;
How to identify a Colnago vintage bike.
Special features of a Colnago Conic SLX Total Spiral.
This frame was built using Columbus Conic SLX Total Spiral tubes which were designed exclusively for use by Colnago. Whilst the name of this model is not very catchy, you can see where it originated from. This frame is easy to identify by measuring the down tube which starts with a diameter of 28.2mm at the head tube and increases to a diameter of 32mm at the bottom bracket (hence the conical description). The down tube also features fluted crimps in the lower half of the down tube to provide extra stiffness.
Other features of this model.
Here are some photos showing the general features of the Colnago Conic SLX Total Spiral frame. You may also notice that the frame in these photo’s is fitted with a modern 11 speed Campagnolo groupset, this highlights the versatility of these vintage frames. Images courtesy of www.steel-vintage.com
The following websites have a large selection scanned Colnago literature including reviews, catalogues and brochures.
I hope you found this article interesting. I have listed the following website pages as general references.
Please remember that this information is only to be used as a guide.
I consider myself an enthusiast, not an expert. The information I have presented in this article is based on my many hours of online research.
In addition, there will always be frames that don’t quite match the characteristics of a particular model as they could have been a custom build, prototype etc. Note: forks can also be swapped between different frames.
I welcome reader feedback in the comments section. Should you wish to suggest an amendment, please include a note advising the source of your information so that myself and other readers can ascertain the accuracy of your information. Note: Trolling or argumentative comments will be removed as they are counter-productive.