Stems
Used road bike stems in 31.8mm and 35mm clamp diameters, from 60mm sprint setups to 130mm aero positions. Alloy and carbon options from Zipp, Deda, PRO, Thomson, and 3T, listed by sellers across the UK.
How much difference does stem length make?
Stem length and angle are the cheapest way to dial in your road bike fit. A 10mm change in length shifts your reach noticeably, and flipping a 6° or 17° stem adjusts your stack height without swapping spacers — worth trying before you replace anything else in your road components setup.
What clamp diameter do I need?
31.8mm is the standard for most road bars. Some newer aero cockpits use 35mm — check your handlebar spec before buying. Older bikes (pre-2010) may use 26.0mm or 25.4mm quill stems.
What length and angle should I choose?
80-110mm covers most road fits. Shorter stems (60-80mm) suit more upright positions or riders with long torsos on compact frames. Longer stems (110-130mm) are common on race bikes. Negative angles (−6° to −17°) create a lower, more aggressive position, and any change moves the reach to your shifters along with the bars.
Alloy or carbon?
Alloy stems from Thomson, PRO, and Deda are stiff and reliable at 120-150g. Carbon options from Zipp SL Sprint and 3T Arx II save 30-50g and damp vibration slightly. Integrated stem-bar combos (Zipp SL-70, Deda Alanera) lock you into one length but are the lightest, most aero option.
What should I check buying used?
Look for scoring on the clamp faces from overtightened bolts. Check the steerer clamp for cracks — especially on carbon stems. Titanium bolts are nice but check they haven't been cross-threaded, and faceplate bolts should all be present and matching. Budget for fresh handlebar tape too, since the bars have to come out of the clamp to fit it.