08/08/2026
❓Are Ceramic Bearings Really Better?❓
The short answer: sometimes—but “ceramic” does not automatically mean better.
When cyclists 🚴♀️ talk about ceramic bearings, they usually mean hybrid ceramic bearings. The balls are typically made from silicon nitride ceramic (Si₃N₄), while the inner and outer races are still made from steel. Fully ceramic bearings, with both ceramic balls and ceramic races, are uncommon on bicycles.
Why use ceramic balls?
When a bearing is loaded, neither the balls nor the races remain perfectly rigid. At each contact point, they deform microscopically and create a tiny flattened contact area.
Silicon nitride is significantly stiffer than bearing steel: its elastic modulus is roughly 300–310 GPa compared with about 200–210 GPa for steel. It is also much harder and approximately 60% lighter. As a result, ceramic balls deform less under the same load and can offer some useful mechanical and wear-related properties.
However, this does not mean that simply replacing steel balls with ceramic ones will transform the efficiency of a bicycle.
The quality of the balls matters enormously
No manufactured bearing ball is a mathematically perfect sphere. There are tiny variations in:
• diameter
• roundness
• surface finish
High-quality bearings use balls manufactured to extremely tight tolerances and closely matched in size. For example, Grade 3 ceramic balls are used in some premium cycling bearings.
This is why an excellent steel bearing can be better than a poorly manufactured ceramic bearing. The word “ceramic” tells you what the balls are made from—not how accurately the complete bearing was manufactured.
And the balls are only part of the bearing
Bearing performance also depends on the quality and finish of the raceways, internal clearance or preload, seals, lubrication, cage design, installation and alignment.
This is important on bicycles because bearing friction is already very small. A well-made, correctly installed and properly lubricated steel bearing can therefore perform extremely well.
Premium manufacturers may combine high-grade ceramic balls with precisely finished steel raceways and careful ball matching. That complete package is much more important than the ceramic material alone. CeramicSpeed, for example, specifies Grade 3 silicon-nitride balls matched with polished hardened-steel raceways.
‼️Be careful with the famous “spin test”
You have probably seen a demonstration where one crank, wheel or derailleur pulley spins dramatically longer than another.
It looks impressive, but it is not a reliable comparison of bearing efficiency while riding.
An unloaded spin test is strongly influenced by grease quantity and viscosity, seal drag, bearing adjustment and preload. SKF's bearing-friction model specifically includes rolling friction, sliding friction, seal friction and lubricant-related drag.
A bearing packed with more protective grease or fitted with stronger seals may stop sooner in a showroom spin test while providing excellent performance and durability on the road.
So, should you buy ceramic bearings?
Ceramic balls have genuine engineering advantages. But ceramic does not automatically mean fast, efficient or high quality.
When choosing a bicycle bearing, look for the quality of the complete bearing: accurate balls, excellent raceways, appropriate seals and lubrication, correct tolerances and good manufacturing.
The takeaway: buy a good bearing—not just a ceramic bearing.
