Seatpost and saddle clamps

Two different parts in one range

The word “clamp” refers to two parts here, with different functions and sizes. Check which one you need before comparing prices.

The seatpost clamp

It is the ring that clamps the top of the frame’s seat tube around the seatpost. Choose it by its internal diameter, which matches the outside diameter of the frame’s seat tube — not the seatpost diameter. A 27.2 mm seatpost fits into a tube whose outside diameter is most often 28.6, 30.0 or 31.8 mm. Measure the existing clamp rather than guessing.

• Bolt-on : lighter, less conspicuous and tightened to a consistent torque. It is the standard on road bikes.
• Quick-release : handy if you often adjust the height or transport the bike with the seatpost removed.
• Hope, Burgtec, Wolf Tooth and Reverse Components offer common diameters in machined aluminium and a range of colours.

The saddle clamp

It is the part that fits over the top of the seatpost and clamps the rails. You replace it if it breaks, if you change rail type, or if you want to switch from a one-bolt to a two-bolt clamp. It is specific to the seatpost : a Ritchey WCS saddle clamp will not fit a Deda seatpost.

• 7 mm round : for steel, manganese and titanium rails.
• 7x9.6 mm oval : for most carbon rails.
• 7x10 mm : for some larger-section carbon rails.
• A saddle clamp designed for round rails crushes oval carbon rails — this is not an adjustment issue; they are incompatible.

The bolts

The range also includes individual replacement bolts — saddle clamp bolts and lower seatpost bolts. Order them by exact part number: length and thread vary between models, and a bolt that is too long bottoms out before it can tighten the clamp.

To find out more: How to choose a road bike seatpost

See also: Road bike seatposts · Road bike saddles · Road bike stems