The increase of sealed bearing use in the bike industry has been a nothing short of a quiet revolution. The weight advantage, smoothness, cost effectiveness, decreased drag and ease of application have been the catalyst for significant leaps in performance and design in the past decade. A sealed, or ‘cartridge,’ bearing (cartridge being the proper nomenclature and a better description) is light, smooth and fast, but by their very nature far from sealed. It has moving interfaces that, in the case of cycling, need to produce as little drag as possible and struggle to create an impenetrable barrier.
To a large extent, cartridge bearings perform well. On the road they typically avoid destructive abuse, but cyclocross is a different story. As the Thrust Bearing inner diameters and outer diameters move ever closer to each other and axle diameters increase, the ability of the wiper seal to resist contaminants is severely compromised. The races are closer together and the seals are tiny — in many wheels barely 2 or 3mm wide — and not sturdy enough to be able to keep out big-time grime.
Cyclocross still draws most of its equipment from the road and therein lies the problem. On a cyclocross bike, made-for-road bearings can incur years of normal abuse and contamination in a single weekend, and that’s without taking into account the real nasties like superfine sand and power washing. As many ‘crossers know, hit the non-drive side of a BB30 dead on with a power washer once or maybe twice and it’s a goner.
I took the liberty of torture testing a quiver of different bearings to see how they fail. I found the results to be reasonably consistent with what I already knew:
Power wash pretty much any cartridge Needle Roller Bearing at close range and it will fill with water.
Power wash a muddy or dirty cartridge bearing at close range and it will drive in water and dirt.
A moving bearing lets in more contaminants than a stationary one. Limit movement of wheels, cassette or cranks when cleaning.
A bearing packed completely with grease is way more resistant to contamination than one with the standard grease load.
Ceramic bearings, once contaminated, resist corrosion better than steel, run smoother and sustain less overall damage.
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