Despite the latest advances in road bike design and technology, your bicycle still relies on the humble ball bearing to ensure it all runs smoothly. There are bearings in the wheel hubs, the headset, bottom bracket, pedals and jockey wheels, and they're commonly made from steel. There has been a lot of hype about ceramic bearings in recent years and many people claim they offer a performance upgrade. But what are ceramic bearings and what are the pros and cons? While regular bearings are made from stainless steel, ceramic bearings are made from ceramic silicon nitride Si2N4.
Ceramic bearings: the pros and cons | clivetern.com
The difference in frictional losses between the top performing ceramic sample and the top performing steel sample is 0. Bottom Bracket efficiency is based on the design and the quality of materials, not necessarily on the type materials i. A cyclist is rarely in a purely vertical orientation with respect to the ground. Basic pedaling mechanics put the bike in an off-vertical orientation with every pedal stroke. Heavy acceleration and climbing can increase the off-vertical angle substantially. Any off-vertical orientation creates a component of lateral loading at the bottom bracket. As a result, the bottom bracket samples were tested with lateral loads, in addition to pure radial loads.
Are ceramic bearings better than steel bearings? We get this one, or a question like it, daily. Secondly, we are only addressing human powered equipment which operates at relatively low-wattage inputs, at low operating temperatures, and at a measly RPMs. I realize there are massive studs among us that can churn out 1, W at RPMs for several seconds, but when we consider that the dynamic load rating for an off the shelf BB30 bearing is over 4, W at 10, RPMsand this work lasts minutes rather than secondswe see that humans put very little strain on a properly engineered bearing. Most companies that make hybrid ceramics just use the same races for everything.
It is ultimately why we ride. If you want to make your bike faster, more reliable and virtually maintenance free in all conditions, look to the XD bottom bracket. Precision ground and USA made at the Enduro Bearings facility in California, the XD combines cryogenically treated nitrogen steel races with Silicon Nitride Grade 3 ceramic balls in a proprietary process that results in the ultimate high performance bearing setup.