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The unbearable lightness of bearings

  • By Michael Robson
  • Published Jan. 16, 2012
  • Updated Oct. 30, 2014 at 9:51 AM EST

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 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 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.

That said, the plan here is to help you to get the most out of your cartridge bearing equipped gear. Here are your options:

Run what you brung:

If you have standard steel cartridges for your BB and wheels take some time to pack them completely with grease. The standard grease load of a performance cartridge is quite low to reduce drag and leaves a lot of room for contaminants to collect. Grease takes up all the space inside the bearing and leaves grit with no space to fit in. If the bearing has not been installed, gently pop off both seals with an X-Acto knife or awl and stuff the races full of grease. If installed, pop off the exposed seal and do the same. Then press the seals back in. When done right you should get a good amount of excess grease squeezing out. Upon install apply some more grease to the outside of the bearing before the dust cap goes on. This creates another barrier and can be wiped off and redone in minutes every couple of weeks.

Yes, I know what you’re thinking: “but doesn’t that create more drag on the bearings?” The simple answer is, sure. But the bottom line is that if you can detect that single watt of resistance while in the throes of a muddy ‘cross race, your talents have been terribly mislaid. It’s simply not that big of a deal and you will get much more life out of your bearings.

Bike washing:

Hand wash bikes when possible. After a ‘cross race I hand wash my bikes and their wheels. With a simple setup and basic gear (bucket, brushes, detergent, degreaser) I can wash both bikes and up to 3 pairs of wheels in 25 mins. Be careful not to jam brush bristles into bearing seals or dust covers. Best practice is to get your bike in a stand with the wheels out so you can wash wheels separately (and properly). When washing your BB and hubs, slow down a touch and take care.

If you have to power wash, don’t blast your bearings. Keep the nozzle of the power washer a safe distance from your bike and never hit wheel bearings or your BB directly with the spray. A typical BB30 has seals on the cartridge bearing and another dust cover over that and they are still no match for a direct hit with 2,500 psi water. At a race, make sure whoever is pitting for you knows how to handle a power washer and try to make sure that person does the washing. I have had stickers blown off, bar tape slashed and bearings destroyed by neutral wash guys.

Out with the old, in with the new:

When replacing bearings consider your options. Ceramic bearings are light, more corrosion resistant and tend to hold up marginally better than steel, but are ridiculously expensive. Ceramic bearings for a wheelset will run you in the range of $170 -$210 whereas the same in steel is more like $40-$60. Same goes for BB30. A SRAM steel bearing assembly will be about $35 and the ceramic will run around $190. I would recommend the same treatment for any bearing prior to install: Pack them with grease. It may be cheaper in the long run to stick with steel bearings, spend a little more time maintaining them and maybe replace them a bit more often. The upshot for ceramic is that they are lighter by a few grams per bearing and given the same amount of contamination they will run noticeably smoother than a standard steel unit. And remember, once you remove a cartridge bearing, it’s done. Even if you press it out it will be pitted and rough. Once installed bearings must be serviced in situ.

Performance upgrades:

You could say the guys at Enduro bearings are pretty fanatical about bearing design and cyclocross. Their latest breakthrough is the XD-15 system. This is a good old fashioned angular contact ball and race bearing that incorporates cartridge quality silicone wiper seals, ceramic bearings and, here’s the best part, you can completely dismantle and service the bearing. The XD-15 gives you the best of both worlds. It is highly contaminant resistant, light (103 grams) and if you do manage to fill it with junk it can be cleaned and repacked in about 10 minutes. Then it’s good as new.

Enduro has been testing these bearings with no grease installed and and reports units running for up to two years with very little or no detectable damage. Just clean, repack and go again. I took to an outboard XD-15 bottom bracket with a power washer and found the outer dual-fin wiper seal to be unusually resistant to water penetration, but it didn’t really matter because the bearing is infinitely serviceable. Enduro only has XD-15 for outboard bottom bracket bearings right now but very soon to be released is a BB30 version and wheel bearings are on the horizon too. I have seen the BB30 version and the guys at Enduro tell me it should be in production before December, 2011.

The XD-15 BB, outboard or BB30, will retail for around $200, once again a serious chunk of change but quite likely the last BB you’ll buy.

When it comes to wheels there are some notables that stand out: DT Swiss and Mavic have an excellent track record for cartridge bearing durability and longevity but I think one of the best hub options out there right now would be the incredible ball and race bearings from Shimano.

I have had the same pair of Shimano clinchers for 5 years now, they have been raced on and trained on, power washed and severely abused and I have never taken a wrench to them. I noticed the other day that the rims are getting pretty worn. I’m betting the rims wear out before I ever need to service the hubs. The combination of gorgeous bearing surfaces, quality materials and fantastic labyrinth seals makes for the most durable hub bearings I have ever seen. Sure a standard ball and race hub might be a few grams heavier but I see way more pros than cons. I’m yet to test the new C35 tubulars from Shimano but they could well replace the C24 as the maintenance free workhorse of Euro ‘cross.

Whichever way you go, a little extra effort on install will dramatically increase the life of your bearings and reduce garage time working on maintenance, failures and replacements. Considering that you would need to get on average five times as much life out of a ceramic bearing to make it worth the cost it might just be better to stick with steel and take care of your bearings. Unless of course we are talking about the Enduro XD-15. The combination of old and new technologies might be the best setup if you want to ride it hard and put it away wet.

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