Trek Emonda ALR 5 Headset Bearing Kit (2 x W540243)

Steel: The cost-effective solution. This option is suitable for all riders and bikes, though if your existing bearings are rusty, consider switching to Black Oxide or Stainless Steel versions.

Stainless Steel: A budget-friendly alternative to Stainless Steel. This is a coating on the Chrome Steel races of the bearing to keep corrosion at bay. Over time, it is possible for the coating to wear, so not as resistant to corrosion as full Stainless Steel, but a good compromise.

Black Oxide: More expensive, but corrosion resistant. This will make the bearings last much longer in headsets that moisture can get into, or if you’re riding in wet conditions a lot. Best for winter bikes or all year commuters.

Hybrid Ceramic: Chrome Steel races with Si3N4 Ceramic balls, this slightly reduces weight and reduces friction within the bearing. Intended for riders looking for the best performance in their headset bearings.

FSA: Premium branded headset bearings, it’s often the case that some sizes are only available from FSA.

FSA Stainless Steel: Premium branded headset bearings which are corrosion resistant. This will make the bearings last much longer in headsets that moisture can get into, or if you’re riding in wet conditions a lot.

FSA Alloy SL: Premium branded headset bearings with outer race housing made from aluminium, offering approximately 25% weight saving over the standard steel version. Best for riders looking to save the most weight.

SLT: Solid Lubricant Technology is designed for use in applications with incidental contact with water and other contaminants. SLT bearings are lubricated for life & cannot be relubricated. The polymer matrix is moulded into the bearing, forming very narrow gaps between the rolling elements, raceways and cage(s), enabling the bearing to rotate. Its saturated with oil & the micro-pores release the oil into the narrow gaps, during operation, providing effective lubrication. Combined with a Black Oxide coating to the raceways this creates a bearing with an increased lifespan. Ideal for bikes with integrated cables.

Enduro Stainless Steel:  The bicycle industry's favourite bearing brand with some sizes only available from Enduro, made from Stainless Steel to ensure maximum corrosion resistance.