Monday, October 15, 2007

10/15/07 - Ceramic Bearings on test!

Shortly before making the big move back to Portland, OR from Nashville I ordered up a ceramic bearing kit for my beloved Bontrager Race X Lite Aero wheels from some of my favorite people on earth; parts distributor The Hawley Company in South Carolina. I opted for the budget offering from Enduro - a well respected cartridge bearing manufacturer - instead of the current gold-standard FSA cartridge bearings. After all; I am a 1) father of a 19-month-old 2) measly sales-person in the bike industry and 3) making an expensive cross-continental move. The Enduro bearings offer nearly the same performance at a slight reduction of the cost of the FSA bearings.

So; first - what makes these things so special? Why have ceramic bearings been getting all this buzz lately?
Stainless steel ball bearings - the industry standard for decades - are strong, relatively light, relatively hard (durable), and relatively corrosion resistant. They can also be created within a respectable degree of roundness - the measure of the precision of the bearing's shape (a rounder bearing is a more perfect sphere and therefore creates less friction and drag because it is not constantly overcoming it's imperfect shape in order to roll). Stainless steel ball bearings; whether in a cartridge (like pictured above) or the traditional cup-and-cone configuration are found in nearly every wheel hub, headset, bottom-bracket and many of the shifters, derailleurs, and brakes on the road today. But, as a mentor of mine is famous for saying: "if better is possible, good is not enough."

Ceramic materials technology allows engineers to take the desirable qualities of the steel bearings and, in layman's terms: bump them up a notch. Ceramic ball bearings are harder, stronger, more durable, marginally lighter, more corrosion resistant, capable of being rounder, and when coupled with a special ceramic-specific lubricant in a cartridge; exponentially lower in friction than conventional steel ball bearings. Less friction equals more speed with less energy expenditure and greater durability. For more detailed information go to FSA's website's ceramic bearing page and download the PDA titled "Ceramic Revolution" available near the bottom of the page. This is one of the better explanations (although a little heavy on "engineering-eze" - consider yourself warned) I have come across.

So, now what have I found in my short time of using them? Well, most manufacturers are quite clear that ceramic bearings do take a little while to "wear-in" and are not an instant "speed-injection". This is actually not really different from most cartridge bearing systems as initial usage allows seals and races to become properly lubed and for drag to be reduced naturally. And, while ceramic cartridge bearings are noticeable lower in drag right out of the box; they get better with time.

So, my busy schedule has allowed me to get about 300 miles in on them since I got them and I have to say that I'm impressed. It's not necessarily a serious "wow-factor" difference; but some of that may have to do with the fact that my wheels were already pretty fast wheels considering. However, the whole drivetrain does seem to have a smoother, "lighter" feel to it with less resistance all around. This almost magnifies the efficiency of the already stiff and efficient Dura Ace 10-Speed parts on my Waterford.

Where I really noticed the reduced friction and improved bearing performance was on a ride about a week ago. I had ridden a loop from our house out along NW Skyline Blvd which involved about 35 minutes of climbing (ah, yes; hard to find that in Middle Tennessee) into the "West Hills" area (yes, the one referred to by the band Everclear) to one of the high points above Portland. The climbing was not the most noticeable arena for the improvements of the bearings; however I did feel a little more light-footed than usual. It was the descent down from the top of Skyline and then down NW Springville Rd. back to our neighborhood that impressed me. My wheels accelerated effortlessly down the descents and out of the corners. In fact - almost too effortlessly! The road was far too curvy and with the early October morning fog still hanging in the air I didn't want to push the speed too much. These already fast wheels had become fearfully fast on a steep curvy descent that I was unfamiliar with which involved dew-slickened shaded corners. I have no doubt that I would easily have broken my previous speed record of 58 mph had I been back in Brentwood and descending Longstreet. 60 mph plus with no problem I'm sure.

So, the verdict is this: Yeah; they're fast. And in the flats they'll save some measurable energy or grant some measurable speed - you choose. But, for the remainder of the winter at least - with the climbing and descending that I'll be doing around here - I'll be entirely honest: These things are scary fast! I'm changing to my hand-built 32 spoke Dura Ace/Bontrager 445 wheels with good-ol' conventional stainless steel cup-and-cone bearings. That should give my brakes a rest too!

Thanks for reading.

13 comments:

  1. Matt,

    Ceramics are also somewhat lighter,dont react with steel raceways and may offer frictional advantages.

    But quick question. Can you feel the minute minute difference in friction and rpm. You're exceptional if you do.

    Frankly, these things don't matter. I think your mentor and FSA needs a reality check. (no hard feelings)

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  2. Read the book "Bicycling Science". Bearing friction of decent steel bearings on bikes is so small that it is not only imperceptible to riders, but basically irrelevant to their power output as well.

    I know you're in the bicycle selling business so I bet you dont care :)

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  3. Ron-

    My experiences with my ceramic bearing wheels may be entirely based on placebo effect. I've had to base my evaluation on different riding experiences and different terrain due to a cross-country move from the Southeast to the Northwest as the bearings were breaking in. As a mechanical engineer, I respect your opinion - but those wheels still scared the trash out of me on a fast descent that is tolerable on my other bikes/wheels. And I love to go downhill - FAST!

    I look forward to reading your blog and more of your input here.

    ReplyDelete
  4. Blah blah blah Ron. Our wheel sponsor, Williams Wheel Systems, makes some awesome wheels featuring the bearings you so poo-poo. In fact, I had the opportunity to ride their old model 30's (approx. 1500 gram aero clinchers) and the new 30's (nearly identical except for a few more spokes, heavier by 30 grams or so but with hybrid ceramic bearings) basically back to back.

    And, I can say that from my experience you'd have to be pretty numb to not notice the difference. I found myself riding the brakes to avoid overlapping wheels in races, and carrying much more speed relative to other racers in tight crit corners relative to the races I did previously with the old 30's.

    So say what you want, I know the things work. But then again, without cynical, opinionated retro-grouches like you, no one would ride lugged steel, friction shifting, or toe clips anymore. The cycling world needs dinosaurs like you. (no hard feelings)

    Matt, great shop you work for, thanks for the unbiased product reviews.

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  5. Dinosaurs?

    What the guy is saying is right on the mark it is simple engineering not speculation.

    What you have essentially done is replace a high quality ceramic bearing for a low quality steel one. If two bearings have exactly the same specification they will perform exactly the same. That is if all the tolerances are identical.

    Now Ceramic bearings are superior at high temperature applications and do weigh slightly less but frictional drag everything being equal will not be any different.

    I also agree that unless you’re previous bearings were just garbage that the actual difference in drag would be to inconsequential to notice.

    You know the things work because you wanted to believe they did. So instead of remaining ignorant and believing carte blanc what marketers feed you, pick up some simple engineering texts and become educated.

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  6. Again, blah, blah blah Sleestak.

    Since you fancy yourself such an engineering guru I look forward to your scientific test between ceramic versus non ceramic bearings. While you're coming up with hard data to discount my opinion I'll be out riding my bike and enjoying my silky smooth ceramic bearings.

    Cheers

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  7. Big Sprinter,

    I think you may have to add Largely Opinionated to your name, not to mention Unneccessarily Insulting or Blindly Verbally Abusive. The amount of drag associated with steel versus ceramic wheel bearings, assuming both types are equally undamaged, is insignificant as a percentage of total drag, especially at high speeds where the drag is comprised of over 90% wind resistance. I'd have to say, based on tests I've seen, that the difference is, at most, 1 watt worth of energy. This is useful in high level racing but of little significance in the efforts and speeds typically found among recreational riders and bicycle communters.

    ReplyDelete
  8. First, let's keep the verbal abuse to a minimum, everyone. Don't write anything you wouldn't say direct to anyone's face. I'd rather my blog not be a magnet for inflammatory comments.

    Now, since I've added a ceramic bottom bracket (which I purchased from Wheels Manufacturing at Interbike this October); I still think I perceive a difference. Again, I'm not beyond accepting that it may be the placebo effect - but I still feel a difference.

    The one common factor I have noticed among people who are knocking ceramic bearings over the last few years is that - as far as I'm aware - they haven't tried them.

    That's all for now...

    Go out and ride!

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  9. Oh, and -

    If you're going to leave an aggressive remark - have a spine and don't use an "anonymous" tag. Use your google ID or some sort of user name and claim your comments.

    ReplyDelete
  10. Hey Matt,

    I have yet to ride ceramic bearings, but I can give anecdotal evidence to support them. I'm a bigger rider, at 6'2" and 187#, so very few racers match my speed downhill. Last year I was passed and out-coasted, on a downhill section by a guy who could not have been more than 160 pounds and several inches, at least, shorter than me. I had to work to match his speed, a few pedal strokes every so often while he just coasted. We had essentially the same gear ("normal" bikes, deep-section carbon rims).
    My guess? Ceramic bearings.

    Cheers.

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  11. I'm going ceramic for no other reason than to try it out for myself.,

    ReplyDelete
  12. Advantages of using ceramic bearings are many. We can use these bearings where the application needs fast but low lubrication.

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