Colnago C40 – The Ultimate Guide

Colnago C40 Ultimate Guide

Introduction

The Colnago C40 was NOT the first carbon frame designed by Colnago, but following it’s release in 1994, the C40 was ridden to victory in some of cycling’s biggest races. Most notably 5 wins in Paris Roubaix – over the roughest parcours found in professional racing.

Colnago designed a number of carbon fibre bikes before the well known C40. These early bikes include;

  • Colnago Carbon Olympic TT Road Bike (1984)
  • Colnago Concept (1986)
  • Colnago Volo (1988)
  • Colnago C35 (1989)
  • Colnago Carbitubo (1989)

Please read my article on Colnago’s First Carbon Fibre Bikes to learn more about these models and what was happening in the industry at the time.

Colnago C40 Prototype (pre-1994)

When researching the C40 on the internet, there is mention of an earlier carbon lugged frame with round carbon tubes rather than the Master profile tubes usually found on the C40. However, I decided to only include C40 frames in this article that were listed in the Colnago catalogs and were therefore widely available to the general public.

Colnago C40 (1994)

The C40 name originates from ‘C’ for Carbon and ’40’ in recognition of Colnago’s 40th anniversary (1954 to 1994). It was in production for approximately 10 years (1994 – 2004) and eventually superseded by the Colnago C50. Over the 10 years, the frame was revised on 3 occasions – so there are 4 different versions of the C40 frame.

The Colnago C40 proved to the cycling industry and consumers that carbon frames were not only light and stiff, but extremely durable. It’s now 27 years since the release of the C40 and carbon fibre is still the material of choice for high performance bike frames. In 1997, the C40 frame apparently cost GBP 1650.00.

In an interview with Ernesto Colnago, the C40 was listed as one of his most favorite bikes. Sir Bradley Wiggins was also quoted as saying the C40 is probably his most favorite bike to look at (having not ridden it yet – he bought a frame on eBay for his collection). With it’s classic lines, racing pedigree and history, it’s easy to see why any serious cycling enthusiast (myself included) would like to own a C40.

For many years, the C40 was also sold with a steel Precisa fork of which there are 2 versions. It wasn’t until late 90’s to early 2000’s when the C40 was sold with a carbon fork (Star or Force models). Detailed information about the different frames and forks is discussed later in this article.

Colnago C40 - First Edition
Colnago C40 – Original design 1994
Image courtesy of Steel Vintage Bikes

Clever Design of the C40: Carbon Lugs.

Whilst the C35 was built as a monocoque frame design (just like modern carbon road bikes), the C40 was built using carbon lugs, which saved weight and could be bonded to the carbon fibre tubes to create a single homogenous structure. Colnago was able to achieve this by taking advantage of Ferrari’s technology derived from exploring new ways to work with composites and join structural members as part of the development of the Ferrari F40 super car.

This carbon lug frame building technique has been used for every ‘C’ series bike since the C40 ie. C50, C59, C60 and the current C64 model. By manufacturing the lugs in 19 different angles, Colnago was able to manufacture frames in many different sizes or with custom geometry – just like they were doing for so many years with their steel road bikes. The image below highlights the variety of lug angles.

Colnago C40 Carbon Lugs
Colnago C40 was built using 4 x Carbon Lugs

Whilst the frame tubes and 4 x lugs were constructed from carbon fibre, alloy parts were still used to complete the frame such as the threaded bottom bracket insert, cable stops, cable guides and the rear drop-outs which were bonded to the seat stays and chain stays. Regardless, when the C40 was released in 1994, it was lighter than any other frame on the market. An Art Decor painted 54 kg frame weighed just over 1 kg (excluding the steel Precisa fork).

Colnago C40 Major Race Wins

The C40 was extremely successful, winning nearly 1000 professional races in 10 years. Paris Roubaix is well known to be the toughest race on both equipment and rider with it’s many rough cobbled sectors which are essentially back roads used by farm vehicles throughout the year. Here’s an interesting story regarding the C40 prior to it’s first race in Paris Roubaix.

When we built the C40 we were the only ones to build carbon frames and all the mechanics and competitor technicians were saying that they would be too dangerous to use on cobbled roads, especially with the straight carbon forks. There was a company that wanted to fit suspension forks on the bicycle, but I wasn’t going to have suspension forks on the C40. The night before Paris- Roubaix I had Mr. Squinzi, the Mapei boss, on the phone to me raising his concerns about using such a delicate-looking thing. I told him that we’d done all of the tests that we could on the frame and the fork and we were certain there would be no problem. I had to take personal responsibility for what was going to happen and I spent all night worrying about it, barely able to sleep. But when I heard that there were 4 Mapei riders in the break, I knew I could relax.

Wikipedia on Colnago

The C40 was ridden to victory 5 times in Paris Roubaix; Franco Ballerini (1995 and 1998), Johan Museeuw (1996 and 2000) and Andrea Tafi (1999).

It was also ridden to victory in 3 World Championships (Johan Museeuw 1996, Oscar Camenzind 1998, Oscar Freire 2001) and the Giro d’Italia (Pavel Tonkov 1996).

4 Different Versions of the C40 Frame

Over the 10 year production period, 4 different variations of the frame were released (dates are approximate).
Please click on each version to learn more.. (coming soon..)

Notes:
1. According to this forum, the bottom bracket insert was changed from aluminium to titanium on C40 B-Stay models in 2003, just before the release of the C40 B-Stay HP. However, in a different article by Lennard Zinn, this change occured in the 2002 C40 B-Stay frames.
2. According to this forum, the shape of the seat/top tube lug on the C40 B-Stay was altered around 2003 and a replaceable derailleur hanger was added to the frame. These changes most likely coincided with upcoming release of the C40 B-Stay HP, but I found no mention of these upgrades in the Colnago catalogs.

5 Different Versions of the Fork Supplied with the C40

Over the 10 year production period, 5 different variations of the fork were released (dates are approximate). Please click on a particular version to learn more.

Colnago C40 Frame Specifications

I believe all versions of the Colango C40 had the following frame specifications;

  • Seat post diameter: 28 mm (not a common size).
  • Bottom bracket: Italian threaded, width 70mm.
  • Headset (early models): 1 inch threaded.
  • Headset (later models): I inch threadless (determined by the fork steerer tube) .
  • Rear frame spacing: 130 mm.
  • Front fork spacing: 100 mm.

Colnago C40 Geometry Chart

This geometry chart was listed in a 1994 Colnago catalog when the C40 was released. Colnago frames of this era still featured traditional geometry with a straight (non-sloping) top tube design. However in 2001, their catalog listed sloping geometry for the small frames sizes (46,47,48) – not show in this table.

Colnago C40 Geometry Chart 1994
Colnago C40 Geometry Chart 1994

Carbon Tubes used to build the C40 frame.

Apparently all the carbon tubes and lugs were manufactured by ATR srl. a high-tech Italian company specializing in carbon fibre fabrication, whom were also suppliers for Ferrari. These parts were then shipped to Colnago where the frame was assembled in their factory. More on that process later in this article. The carbon tubes were refined over the 10 year manufacturing span of the C40 to make them stiffer and lighter. Both the top and down tubes feature the Master profile as seen in the image below.

Colnago C40 frame tubes
Extract from 1994 Colnago Catalog

It is a real anticipation of 21st century! It is a frame which combines top stiffness (all torque-flexions are missing) and lightness: 1000 gr. for a cm. 54 size Art-Decor painted! Lugs and tubings are both in high quality composite material and their exceptional characteristics are due to the use of the most advanced fibres and assembly methods. The two main tubes have the classic Master profile of Colnago, which is particularly difficult to build with composites. The homogeneity of the used materials allows the fastening process to obtain a structural, undestructible soldering, which permits to obtain a monocoque frame with all the “composition” advantages. The patented manufacturing methods permit variations in thousandths of sizes and lugs angles.

Extract from 1994 Colnago Catalog

C40 Frame Assembly Process

Rather than simply cut the carbon tubes straight and fit them into the lugs, Colnago precisely miter each carbon tube to ensure the end of the tube perfectly mates with the internal surface of the lug, with no gaps, to achieve maximum strength. Once the frame tubes are cut to the required lengths, the ends are coated in a special bonding agent before being inserted into the carbon lugs. The assembled frame is positioned on a special jig to ensure everything is set in perfect position.

The following images from a 1997 Colnago catalog show the assembly process of a C40 frame.

Colnago C40 frame assembly
Colnago C40 frame assembly
Colnago C40 frame assembly jig
Colnago C40 frame assembly jig

Galvanic Corrosion in early C40 frames

We all know that one of the benefits of carbon fibre is that it doesn’t rust. Unfortunately though, it can accelerate corrosion in metal parts that are connected to it. This is a known as galvanic corrosion.

Search around the web and you’ll find plenty of discussion related to C40 frames experiencing galvanic corrosion. Carbon fibre is an electrically conductive material and when coupled to fittings comprised of untreated aluminium alloys, these fittings become susceptible to galvanic corrosion.

In the case of a bicycle frame, when a large surface area of carbon composite is coupled to small metallic parts (such as cable guides, cable stops and rear drop-outs), the rate of galvanic corrosion is extremely high due to the high cathode to anode surface area ratio (Ac/Aa).

As I understand, this issue was resolved in later versions of the C40 frame by treating the alloy parts. Titanium bottom bracket sleeves were also used in late model C40 frames.

The areas susceptible to corrosion on the early C40 frames were;

  • The alloy rear drop-outs. They are bonded to the seat stays and chain stays in the rear triangle.
  • The internal aluminium bottom bracket sleeve.
  • The alloy cable routing guides and stops.

The best ways to prevent corrosion are;

  • Make sure the paintwork on all metal parts is in good condition to provide a barrier to the elements.
  • Store the bike in a dry location (away from salt air if you live close to the ocean).
  • Avoid riding in wet weather where salt is present on the road.
  • Wash and dry the bike after riding in the rain.
  • Wipe off any perspiration after a ride.

References

I hope you found this article interesting. I have listed the following website pages as general references.

About Me.

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.

Comments.

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.

2 thoughts on “Colnago C40 – The Ultimate Guide

  • Hello,

    I was looking at a Dream Art Decor frame on ebay. I noticed the work aluminum was spelled Alluminium on the frame. Does that sound right to you? It’s a frame and fork only. It has a headset for a quill stem and an octalink BB in it so I think that dates it to the mid 90s

    • Hi Lee, sorry I haven’t spent any time researching the Colnago Dream, but I believe they were released in the early 2000’s.

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