Spoke Nipples
Used spoke nipples and spokes for mountain bike wheel building and repairs, listed by UK sellers. Brass, alloy and steel nipples sit alongside straight-pull and J-bend spokes from DT Swiss, Sapim and Wheelsmith. Match the length, gauge and nipple type to your rim and hub before you buy.
What do spokes and nipples actually do?
Spokes and nipples are the tension members that connect hub to rim and keep the wheel round, true and stiff. Individual spokes are cheap replacement parts — the real cost is the labour of truing the wheel afterwards. The same knowledge covers a full wheel build and a broken spoke replaced trailside: spoke types, lengths and nipple materials.
J-bend or straight-pull spokes?
J-bend spokes have a 90° bend at the hub end that hooks through the hub flange — the traditional and most common type. Straight-pull spokes have no bend and slot into straight-pull hubs (DT Swiss 240/180, some Mavic); they're slightly stronger because there's no stress concentration at the bend, but they limit you to straight-pull hubs. Butted spokes such as the DT Swiss Competition and Sapim Race are thicker at the ends and thinner in the middle, making them lighter and more fatigue-resistant than straight-gauge because the thin middle section flexes instead of concentrating stress at the elbow.
What spoke length do I need?
Spoke length depends on the hub flange diameter, rim ERD (effective rim diameter) and the lacing pattern. Every hub-rim combination requires a specific length calculated with a spoke calculator — DT Swiss and Sapim both offer free online tools — and lengths are measured to the nearest millimetre. Get it wrong and the nipple either bottoms out on the spoke thread (too long) or doesn't have enough thread engagement (too short), and either compromises the build.
Brass or alloy nipples?
Brass nipples are heavier at 1g each against 0.3g for alloy, but they're much stronger and easier to work with: they don't corrode onto aluminium rims and they don't round out under a spoke wrench. Alloy nipples save 20-25g per wheel but can seize in the rim, strip more easily and corrode in wet conditions. For MTB use in UK weather brass is the better choice — the 20g penalty is meaningless next to the reliability gain, and alloy only really makes sense on XC race wheels where every gram is scrutinised.
How do I replace a broken spoke?
Carry a spare spoke and a spoke wrench on rides. If a drive-side rear spoke breaks, the wheel pulls out of true toward the non-drive side — usually rideable, but it will rub the brake caliper. Reaching the nipple means getting the tyre and tube off the rim, then thread the new spoke through the hub flange, match the lacing pattern of the neighbouring spokes (over-under-over or under-over-under), thread the nipple on and tension to approximately match the surrounding spokes. A proper retension and true at home finishes the job.