This is a topic that I have answered before, although the below is quite extensive I have tried to put it all across in a plain and simple manner, they are my opinions based on over 30 years as a club cyclist and over 20 years as a specialist cycle retailer,
as such I must add these are my personal opinions; I fully respect that others may have some different opinions to mine.
Frame Materials:
Frames made of Aluminium Alloy: Often simply referred to as ‘Alloy’ Light, cheap, reasonably robust although some do comment that aluminium alloy frames are not as comfortable when compared to the others; in part this is why most will not use aluminium alloy forks, most current road bikes will use steel or carbon. Aluminium Alloy supposedly has the most performance drop off, which in fairness only really effects a racing cyclist where a few percent reduction in performance can make the difference (especially in their heads) of winning or coming second, in reality that applies more to the older lighter frames when Pro’ riders used extremely light versions (now most pro teams use Carbon), the modern budget frames use a heavier, more robust alloy and are of course aimed at a different style of riding. They are now the most common option in the mid range and upwards frame sets, fairly robust, as they will normally dent as apposed to crack. Normally the price dictates a purchase of a frame built in alloy, that does not mean that you will not be satisfied, you will see quite a few older frames still being ridden by club cyclists who find them perfectly adequate, plus many don’t have any complaints re’ comfort or performance drop off. Although most refer to these frames in general terms as ‘alloy’ if we are being pedantic then strictly speaking this is wrong, as steel is an alloy of carbon and iron, titanium is normally aluminum and vanadium, for example
Van Nicholas use 3% Aluminium, 2.5% Vanadium and 94.5 Titanium, which they simply list as 3/2.5
Frames made of Carbon: With sufficient research and development can result in a bike that is comfortable, very light and efficient at transferring energy into propulsion as the material does not flex as much as other materials. Although strong they can be more delicate, where other materials dent, Carbon is more likely to crack, although I don't believe that they are as delicate as many fear them to be, quite a few have been ridden for a few years now and still going strong. Most common rider is a racing cyclist or someone who still likes to have a ‘best bike’ that can to an extent have a more precious existance than say audax or touring bike, where robustness may be more of a consideration.
Frames made of Steel:Comfortable, very durable (if built correctly) with low performance drop off with age. These days still a popular choice for club riders who like to know that their frame has been built in the traditional way by a craftsmen. Production bikes built with steel are less common, although it remains popular with the companies that still cater for touring bikes.
Many cyclist like the fact that they are having something built often to their own specification, you can personalise your frame with your own braze on items, light bosses, extra bottle bosses etc, you can even chose your own colour. In the past all top quality frames were purchased this way, as it was how you got exactly what you wanted, both in quality and especially frame size. The old diamond shape frame being less adaptable in terms of variations in riding position than the modern sloping top tube frames; even Lance Armstrong used an off the peg frame size. Although I fall into this category, as in uses as steel frame, not Lance Armstrong, I have to admit that modern off the peg frames are now so good both in terms of production quality and the flexibility that the modern geometry gives you to achieve the perfect riding position, that the necessity to have a bike made to measure is less of an issue. In more recent years steel frames are starting to make something of a come back, as many realise that in many ways steel is a better option than aluminium alloy, especialy when it comes to comfort.
Frames made of Titanium: Becoming more popular, virtually no performance drop as they don’t even rust, comfortable, light, yet robust. Performance wise not quite as responsive as well designed carbon or alloy (alloy when new that is), although really it is that not far off, some pro riders used Titanium like Magnus Bakstedt a former Paris Roubaix winner, other Pro Teams used Titanium frames painted up to look like normal production bikes of their team sponsors, often used in races where comfort can become an issue, for example over the cobbles of the Paris Roubaix, as riders are bashed about so much it can lead to fatigue; however these days most pro riders use carbon.
The down side is that Titanium is very hard to work/build with; so most don't! On the upside because of this the workman ship simply has to be of top quality and it shows, most Titanium frames do look and are very well made. Most common used when someone wants a fast, responsive, light comfortable yet robust, durable bike and of course where price is not so much of an issue. Titanium is therefore and ideal choice for longer day rides/audax/touring bikes.
Frame material conclusion, Opinion is often very divided when it comes to frame materials and if it effects how the bike rides or not. Many will state that they can tell a huge difference and by the same token many will state that the frame material makes no difference at all. I would say I fall somewhere between both, I have ridden a huge variety over the years, when riding bikes similar in set up in nearly every respect apart from the frame material I would say that I can't tell a huge difference, but I can feel more than none that's for sure.
A quality designer and manufacturer will be sensitive to the material they have used, so I would expect the bike to perform how it is supposed to and give you good long service, regardless of what it is made of. So although the frame material is indeed a consideration I believe that many are far more concerned about what they should or shouldn't use than perhaps they need be, making sure you have the correct style of bike with the correct set up interms of the equipment specification and size/bike fit is more important.
For example in your case you have mentioned "I currently ride a full carbon (Giant TCR C3) and after 3 hours in the saddle, feel pretty battered about", this may well be down to the fact that you may have it set up long and low like a full on racing bike, resulting in a position that you may find is at the edge of you capabilties iterms of comfort;at the end of a three hour ride will begin to have an impact. I assume this may well be why you have considered a Specialized Roubaix, yes it is set up to be more comfortable with Zertz inserts and frame design with a view to comfort as well as performance, but it is also set up to allow the rider to achieve a slightly more comfortable position, so slightly shorter and higher. Even their off the peg Tarmac frames offer a slight degree of comfort, if you look at their 'S Works' frame sets, the larger sizes are actually slightly lower at the front end, sometimes normal athletes can forget that top racing cyclists not only have huge lungs, heart and
Billy Whizz legs, but they can physically get into the long and low position that shall we say normal people can find hard to achieve and then have to maintain for hours on end.
Before you invest in a new bike, you have little to lose but time in seeing what you can do to your Giant bike in a bid to make it more comfortable, it is often the case that you need to make the bike fit you, not the other way around.
Paul_Smith
