Ceramic balls are lighter than steel balls and roll faster. This means there will be less friction in the bearing, resulting in lower generated heat and a lower rolling resistance. It also means a longer life span.The advantages of ceramic bearings are often viewed as a myth and, the fact is, even an experienced cyclist will find it hard to physically sense a difference between different bearings on their bike, all other things being equal.

We faced our first challenge early on in simply getting the right bearings from Boca. An average rear wheel hub has three bearings and the front has two bearings; the tricky thing is that these bearings can be of different sizes and each bearing brand does sizing differently. To make it even harder, each wheelset model from a brand can use different sized nsk bearing and even a new year’s model (from 2011 to 2012, for example) can mean different sizes.

To help with this complexity, the Boca Bearings website allows you to select a wheel brand and exact model in order to get the right sized bearings. For each bearing size you will find the different types of bearings available: chrome, steel, hybrid ceramic, and complete ceramic. For bearing selection, the important dimensions are the inside diameter, outside diameter and the width, so vernier calipers are particularly useful in measuring your current iko bearings first.

For the Mavic Ksyrium road wheels we were initially going to use in this review, we had the bearing dimensions but couldn’t match the model nor find all of the bearing sizes on the Boca site. We then tried to find bearings for some Bontrager mountain bike wheels and, though these wheels were not listed, we found matches for four of the five bearings, so we ordered them.

After a lot of planning it was time to get our hands dirty. We pick up the action with the old bearings already removed. Before considering getting the new bearings in, the hubs first need to be prepared, particularly if the wheels have already seen a bit of action. A good clean with a rag will get any grit out and a blade can be used to remove any burrs inside the hub and at the hub ends, so that metal shavings aren’t pressed inside when the bearings are fitted. After a coating of light oil (as opposed to grease) the hub is ready. The key to pressing in the bearings is to press them in perfectly straight, so don’t even think about using a hammer.

Removing the old bearings and fitting the new ones requires specialist tools and, since all hubs are different, there is no single tool that will do it all. Aaron Dunford is mechanically adept and he had built some of the tools we needed for this job. Some tools were as simple as nuts and washers on a quick release skewer combined with the old "sealed ball bearings" to safely press the new ones in; the quick release is used to slowly leverage them into place. Where the skewer doesn’t work, a long threaded bolt with properly placed washers and nuts becomes a tool that can hold the new bearing properly in place as a spanner slowly tightens to press the bearing in. Does it sound like DIY? Well it is, but in the hands of an experienced mechanic.

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