FRAME MATERIALS

Technology plays a large part in cycling, be it in design, clothing or nutrition. One of the most considered choices for both the novice and experienced rider is the frame. Manufacturers have the option of building in steel, aluminium, carbon, titanium, magnesium or even a combination. They can choose the tube thickness, the way the tubes are bonded or welded and can control with great accuracy the way the bike will feel when climbing, its stability when descending and how comfortable it will be on a long ride. Different materials have different weights, produce different handling characteristics and have different prices. In this section we’ll try to guide you through the material maze and explain why we stock frames made in different materials and from different brands.

Steel:

For many of us ‘thirty somethings’ our first bike was made of steel. Remember lusting after a Raleigh Record Ace and watching Team Banana in the 70’s? Reynolds 501 and 531 tubing? Well, steel is still around and for good reason. Mass-market children’s bikes and cheaper commuter cycles use low quality, heavy steel to achieve a very low price point and as a specialist road shop we leave this market to the high street stores. However, high quality steel is a great choice for a frame builder. It gives a 'classic' feel – comfortable to ride with a little ‘springiness’ which is particularly useful on the pock-marked British roads –and hence it is used in the construction of many audax and touring bikes. Surprisingly, a quality steel frame can weigh less than a medium range aluminium one. This is down to the way the tubes are ‘butted’ together, which allows for a light, quality thin-walled steel tube to be used. Steel is highly resistant to fatigue and is therefore very durable if looked after.

Aluminium:

As aluminium is not as dense as steel, it makes for a generally lighter frame. It is easy to work/machine, keeping costs down. Different tube sizes, grades and mixes are used to give varying degrees of stiffness and strength. Computer aided design coupled to innovations in the manufacturing process have allowed frame builders to create tubes that can be one profile and thickness at one end and have completely different dimensions and thickness at the other, which lowers weight and enhances performance. This can change compliance and improve aerodynamics, using bladed tubes for example. Aluminium tends to be used to make a stiff frame which is ideal for racing, as very little of your energy is lost, although often it is mated to a carbon rear end to soften the ride. Like steel, you can find cheaper aluminium frames in high street stores at very low prices but these normally give a very jittery and overly stiff ride. Aluminium tends to suit heavier riders where a more compliant material coupled to their greater mass would give an unacceptable loss of energy in the frame. It has the downside of a shorter lifespan than steel as the stiffness can cause stress fractures but with modern production processes on the more expensive frames, this is now a rarity.

Titanium:

Titanium has always been seen as an exotic and expensive material. It is hard to work in to tubes, weld and paint, leading to higher production costs and a tendency to be found in a natural bare metal finish. Whilst cheaper titanium frames are finding their way on the market, the top-end frames sit in the highest price bracket of all. On the flip-side it has excellent corrosion resistance so doesn’t need painting which keeps the weight down. High quality titanium gives a good blend of power transfer, low weight and comfort making it a popular choice for long distance riding. Two different grades of titanium are generally used, 3AL/2.5V and 6AL/4V; the numbers reflect the percentage mix of aluminium and vanadium. The former is slightly 'whippy' like a good steel frame and gives a relaxed ride while the latter can be made extremely light and stiff as large diameter tubing can be utilized without a weight penalty. For someone seeking a frame with the comfort and durability of steel, the stiffness of aluminium and understated looks Ti is a tempting proposition. In any case, titanium can be a bike for life.

Carbon:

Often called ‘the wonder material’, and around since the mid eighties, carbon is still relatively new when compared with its rivals. It’s also the material that causes the most confusion as it can now be found at virtually all price points. Perhaps the most important point to note is that there is a huge variation in grades of carbon. Carbon tubes are constructed in layers mixed with resin. Cheaper carbon, which is visually indistinguishable from the higher price tubing has a large amount of resin and often just a couple of layers of carbon. This keeps costs low but makes the tube more brittle and fragile; these are generally the frames that you hear about breaking. Better quality frames use carbon with stronger and lighter weaves that require far less resin in their structure. One of the big benefits of a carbon frame is that it can be used to make tubes and lugs of almost any shape and size; this gives the potential to 'fine tune' different areas of a frame, such as a stiff bottom bracket area and compliant top tube. A stiff head tube can drastically improve acceleration and handling, while each tube can be stiff in one direction and compliant in the other. Lateral stiffness and vertical compliance alter ride quality, as does frame geometry and wheel/tyre choice. Designs can vary from lugged to single piece monocoque construction, giving a huge variety in ride quality and performance.

Magnesium:

This is a much denser material than aluminium and it is imperative that the quality of the manufacture is very high. This prevents corrosion later in the frames life. This necessity puts off many manufacturers and the high quality of work is reflected in the higher cost. The ride feel is similar to super-high quality aluminium, with good energy transmission and sharp handling if matched with the right geometry.

Frame Geometry:

Most frames use a 'double triangle' design and have done for years. The cycling racing governing body, the UCI, have strict rules for geometry and weight of racing bikes used in the pro peleton. We refer to most frame geometry using virtual or actual top tube length (a lot of bikes have a sloping top tube), seat/head tube angles, seat/head tube length and wheelbase. With variations of these measurements, in addition to the different frame materials, the geometry can be used to alter a frames intended use, eg longer wheelbase for touring/audax use, shorter for road racing, wishbone-shaped rear seat and chainstays for comfort, relaxed head tube angle for less direct handling etc etc.

Frame size:

As we are all beautiful shapes and sizes, custom fitting is the final factor in reaching the best frame for your intended use and budget. You would be amazed the difference you get from moving your saddle back or forwards a couple of millimeters (seriously), or changing the length of your stem or the position of your foot on the pedal, or the length of your crank. We could go on and on but the best advice we can give is to visit us to be measured properly. We offer superb pre-set geometry from four manufacturers and a custom build service in nearly all materials, starting from £499. We are professionally trained on our state of the art measuring jig and we’ve got a lot of years of cycling experience to draw on (yes, we’re getting old).