Road bike frames

Base your choice on your leg length (inseam) and torso length, then refine your selection using the manufacturer’s size charts. The basic method: multiply your inseam length (in cm) by 0.67 to obtain an indicative frame height. Manufacturers’ size charts (Giant, Trek, Specialized) cross-reference overall height with torso length to guide you towards the right size. If you’re between two sizes, a rider with a long torso should choose the larger size and compensate with a shorter stem; a rider with a short torso should choose the smaller size with a longer stem. A posture assessment remains the only way to accurately confirm the right size before making a purchase.

Race geometry (compact, aggressive) places the cyclist in a low, stretched-out position for aerodynamics; endurance geometry positions the torso higher for comfort over long distances. Race frames (Specialized Tarmac, Trek Émonda SL) have a short stack and a long reach: a position on the lower part of the handlebars similar to that of professionals. Endurance frames (Specialized Roubaix, Trek Domane) have a higher stack and a shorter reach, often with integrated suspension systems. For cyclists riding cyclosportives and long rides, endurance geometry offers greater comfort without sacrificing performance. Racers and very flexible cyclists prefer race frames.

The monocoque is manufactured as a single continuous piece, whereas the tube-to-tube method assembles individual tubes. The monocoque (manufactured in a single moulding) allows for optimal fibre orientation in each area, better control over stress distribution and a cleaner finish. This is the technique used by high-end models (Specialized Tarmac SL8, Trek Madone). The tube-to-tube method assembles prefabricated carbon tubes bonded with resin: less expensive, it allows for small, customised batches (bespoke carbon frames) but with lower stiffness and precision. For mass-produced frames, the monocoque is superior; for bespoke, handcrafted frames, the tube-to-tube method remains a viable solution.

Yes, and this is common practice for cyclists who wish to customise their bike. Buying a bare frame (without a groupset or wheels) allows you to choose each component freely. Bare frames cost from €500 (entry-level aluminium) to €5,000 and above (high-end carbon). Assembly requires specific tools (bottom bracket remover, caliper for alignment) and intermediate mechanical knowledge, or you can have it assembled at a workshop. Points to note: check the frame’s compatibility with your chosen groupset (bottom bracket standard, cable routing, brake type, thru-axle).

A detailed visual inspection under low-angle light, followed by a resonance test using light tapping. After a fall, inspect each tube of the frame under a strong light, looking for marks, cracks or matt areas surrounded by shiny areas (a sign of delamination). Areas at risk: fork steerer tubes, seat stays on the impact side, seat tube, top tube. Tap lightly with a coin: a deep, full sound indicates intact carbon, whilst a hollow or dull sound indicates internal delamination. If in doubt, have it inspected by a specialist workshop or send it to the manufacturer. Never ride a carbon frame that is suspected of being damaged.

A high-quality carbon frame lasts 20 to 30 years under normal use, but material fatigue is a real and cumulative issue. Unlike steel, which can last indefinitely, carbon undergoes progressive fibre degradation under cyclic stress. Some materials engineers estimate this dynamic lifespan at 5 to 10 years for intensive use (competition, 15,000 km/year), and 20 to 30 years for moderate recreational use. The manufacturer’s warranty (2 to 5 years depending on the brand) does not cover normal wear and tear but only manufacturing defects. A carbon frame that has suffered a serious fall or a localised impact must be inspected even years after the incident.

Yes, in some cases, by workshops specialising in carbon repairs. The repair involves removing the damaged fibres, reinforcing the area with replacement carbon plies, and finally sanding and varnishing. Workshops such as Calfee Design (USA) or Carbon Repair (Europe) offer this service. Cost: €200 to €600 depending on the size of the damaged area. Advantages: for a high-end frame (Dura-Ace, Colnago) worth €3,000 or more, repair is economically justified. For an entry-level frame, replacement is more sensible. Carbon repair requires specific equipment and expertise: never attempt it yourself.

These solutions offer weight savings, aesthetic integration and sometimes aerodynamic benefits, but at the cost of reduced adjustability.Frames with integrated seatposts (Trek Émonda SL, Colnago C68 AGB) weigh 50 to 150 g less than a conventional seatpost but do not allow for easy height adjustment. One-piece full-carbon forks (Trek Madone, Specialized Tarmac SL8) reduce weight and drag but require complete replacement if damaged. For competitive riders with a fixed position, these solutions are justified. For cyclists who regularly adjust their position, a standard fork and a conventional seatpost offer greater flexibility.

Cleaning without harsh solvents, strictly adhering to torque specifications, and protecting against impacts are the three key rules. Never use acetone, WD-40 or strong degreasers on unpainted carbon areas. Clean with water and mild soap. Fixing points (bottom bracket, derailleur hangers, seatpost clamp) are stress points: always tighten to the torque specified in the manufacturer’s documentation. Apply carbon grease (FinishLine, Muc-Off) to metal/carbon contact points to prevent galvanic corrosion. Store the bike away from direct UV light and excessive heat, which degrade the resin.