Road bike frames generally follow the classic ‘diamond’ design but even so there are many different types designed for the needs of very different riders – from super-stiff racing machines to comfortable long-distance tourers, from entry-level all-rounders to cutting-edge carbon fibre speed weapons.
The type of road frame that is right for you will depend not only on the budget available but also on the type of riding you intend to do. In general, road frames will fall under two broad categories, with geometry to suit – those intended for leisure and sportive riding (sometimes also referred to as ‘endurance’ frames) and those intended for competitive racing (although race frames can of course be used for leisure and endurance riding!).
Leisure and sportive frames
Road bikes for leisure or non-competitive riding – including the increasingly popular Audax or Cyclosportive types of long-distance organised cycle events (including charity cycles), as well as fitness riding or winter training – will make more concessions to comfort and everyday practicality than out-and-out race frames. A relaxed frame geometry allows for a more upright riding position that is less aerodynamic than the ‘flat back’ racing style but far more comfortable for the newcomer or leisure cyclist. Frames will feature ample clearance for wider, more comfortable tyres as well as mounts for mudguards and even front and rear racks. Bikes like this may often carry the ‘endurance’ label, and are ideal for either beginners to the sport or for those who value comfort over long distances and rough surfaces.
Competitive racing frames
Road bikes aimed at racing enthusiasts are designed with light weight and efficiency taking priority over comfort. For optimum power transfer, racing bikes feature super-stiff frames with long top tubes, short head tubes and steep head and seat angles for a ‘stretched out’ racing position, with the handlebars generally positioned below the level of the saddle. Bikes like this are more suited to the experienced rider.
NOTE: While these categories are not strictly defined – and many manufacturers will aim to create frames that are effective ‘all-rounders’ and as comfortable on an evening club crit as they are on a charity 200 – the distinction between racing/not racing is a useful one to bear in mind when considering the many road frames on the market.
Road frame materials
The frame is the heart of any road bike, and improvements in technology and materials mean that excellent quality frames are available to riders even at the budget end of the market. The most common materials used are aluminium, carbon fibre, steel and titanium.
• Aluminium: Relatively inexpensive to manufacture, aluminium frames are found on many bikes in the low- to mid-range sectors of the market and offer reasonable performance at a good price. Lightweight, strong and stiff, aluminium is however sometimes percieved to be a harsher ride than carbon fibre – although any difference between top-end alu frames and lower-end carbon are minimal, and plenty of experienced riders prefer an alu steed.
• Carbon fibre: The majority of bikes in the pro peloton have long been built around a carbon fibre frame, and for good reason. Strong, stiff and lightweight, carbon is also favoured for its vibration damping properties, making it comfortable over long distances but also very efficient at power transfer. As the technology has matured carbon frames have begun to appear at lower price points, bringing the material’s benefits within the grasp of the ordinary rider.
• Steel: Steel frames offer a supple, springy ride much beloved by those who favour ride comfort over optimum stiffness and light weight. Not the racers’ choice owing to a weight penalty, and rare among production bikes from major manufacturers, but remains very popular among long-distance tourers and lovers of the classic steel ‘spring’.
• Titanium: Lightweight, strong and supple, titanium frames offer ultimate all-round performance but at a premium price due to how difficult the material is to work with. Because it doesn’t corrode or lose its ride characteristics over time, titanium is sometimes the frame material of choice for riders looking for a ‘bike for life’.
Frame geometry: ‘Traditional’ vs ‘Compact
Materials aside, road bike frames are often classified as ‘traditional’ or ‘compact’ (also ‘sloping’) geometry. Traditional frames feature a horizontal top tube, with compact frames featuring a sloping top tube. The relative merits of each design are open to debate and are often a matter of rider preference, with traditional frames regarded as stable and comfortable and compact frames being quicker and more responsive, with a lower centre of gravity.
One important point to note is in relation to sizing – because of the sloped top tube, compact-framed bikes of an equivalent reach – (reach – distance between saddle and handlebars) to traditional models will carry a smaller frame size. For example, a 56cm traditional frame will be equal to a 52cm compact frame. Compact-framed bikes are also typically available in a smaller range of sizes, with seatpost height adjusted to suit the rider.
Female-specific road frames
Women have a different body geometry to men and the range of women-specific road frames on offer reflects the different needs of female cyclists. Because women tend to have longer legs in proportion to their torsos than men, women’s-specific frames will have a shorter top tube to bring the handlebars closer to the saddle while still enabling full leg extension.
They can also feature adjustments such as a relaxed head tube angle and lengthened head tube as well as a slightly steeper seat angle, all aimed at increasing comfort and stability.