Frames

Aero, endurance or gravel?

Aero frames prioritise speed, endurance frames raise the front end for comfort, and gravel frames add clearance and mounts. Decide which of the three suits the riding you actually do before you start comparing individual listings, because the differences between the categories are far larger than the differences between frames within one.

Which frame material should you choose?

Carbon dominates from mid-range up, but aluminium, steel and titanium each have genuine advantages depending on your riding. Carbon fibre is the default for performance frames, with a high stiffness-to-weight ratio, mouldable into aero shapes, and tuneable compliance through layup design; high-modulus carbon (Toray T800/T1000) is lighter and stiffer than standard modulus (T700) but more brittle on impact. Aluminium frames from brands like Canyon, Giant and Cannondale are remarkably competitive, as modern hydroforming and butting techniques have closed the gap on carbon significantly. Steel (Reynolds 725/853, Columbus Spirit) offers unmatched ride quality for touring and all-day riding, plus it is repairable. Titanium (Reynolds 3Al/2.5V, Dedacciai) is the forever frame — corrosion-proof, fatigue-resistant and lovely to ride — but custom builds from Enigma, Moots or Lynskey cost accordingly.

What do stack and reach tell you?

Stack (vertical height from the bottom bracket to the head tube top) and reach (horizontal distance from the bottom bracket to the head tube) are the two numbers that define fit. Race frames have low stack and long reach for an aggressive aero position, while endurance frames increase stack for a more upright, comfortable one. Head tube angle (73-74° race, 71-72° endurance) affects steering speed, bottom bracket drop (65-75mm) affects stability, and chainstay length affects wheelbase and snappiness. Compare geometry charts between frames rather than relying on nominal sizing, because a 56cm from one brand rides very differently from a 56cm from another.

Which standards do you need to check?

Before buying a frame, check which standards it uses, as they decide what will bolt on. Bottom bracket: threaded BSA/English is easiest to maintain, while press-fit (BB86, PF30, BB386) can creak but is lighter. Seatpost diameter: 27.2mm is standard, though many aero frames use proprietary D-shaped posts. Headset: most modern frames use 1-1/8" to 1-1/2" tapered. Thru-axle spacing: 12x100mm front and 12x142mm rear is standard for disc road, while quick-release is still found on rim brake frames. Some frames only route electronic groupsets rather than mechanical cables, so check all of this against your components before purchasing.

What should you check buying a used frame?

Inspect carbon frames carefully, because crash damage can be invisible: look for cracks, dents or paint ripples around the head tube junction, the bottom bracket area and the dropouts, and tap-test suspect areas, where a clear ring means solid carbon and a dull thud suggests delamination. Aluminium shows crash damage more obviously as dents and creases, and cannot be repaired; steel can be straightened and re-welded by a specialist. Check the headset and bottom bracket faces are not corroded, verify the frame has not been recalled using the manufacturers' online recall databases, and measure the frame yourself rather than trusting the seller's stated size.