Wednesday, June 4, 2008

How To Remove and Install Sealed Bearings, How To Overhaul Sealed Bearings, and What Products to Use

CONTENT THYSELF

Get it? It’s supposed to be a pun on the word “content:” normally, you would pronounce the phrase “content thyself,” with the emphasis on the second syllable, but I’m pronouncing it “content,” with the emphasis on the first syllable, as in “web content,” which is what I’m going to try to provide more of in this blog from now on. Many of my readers, about seven of them, have mentioned that I basically talk too much, so what I’m going to try to do is show, not tell, with links, photos, videos, how-to’s….mostly, I don’t want to end up sounding like Nicholas Fehn:

http://www.nbc.com/Saturday_Night_Live/video/play.shtml?mea=229107

Content….” Hilarious. In linguistics, I think it’s called a heteronym, when two words are spelled the same way but pronounced differently, and have different….

Wait a minute….never mind. Onwards and upwards, to

HOW TO IMPROVE YOUR SMILE AND OVERHAUL A SEALED BEARING AT THE SAME TIME

Why, with a dental tool, of course….

In the current issue of Velonews, Lennard Zinn, who by now is so renowned that his name would be capitalized even if it weren’t, has an article entitled Upgrading To Ceramic Bearings: A How-To Manual, in which he provides instructions for removing steel bearings and installing ceramic ones. Here’s the article in pdf form:


If you click the arrow to the left of the word "ipaper," a pull-down menu will appear allowing you to do things like email the pdf to yourself or a friend, or print it out. If you click on the maximize tab in the upper right, a full-sized version will appear on your screen, but you'll need to click the back button on your browser to return to the blog.

Velonews is a large publication with small margins, and my poor little 3-in-1 couldn’t handle its full page size, so I had to scan it half a page at a time to keep it legible. If that doesn’t work for you, I encourage you to buy the issue. It’s a good one, really.

Anyway, I have to say, with all due respect, that I’m surprised Velonews printed the article. As usual, Zinn covers everything with his framebuilder’s attention to detail, and provides all the “tricks” that you would expect from this kind of article, like using sockets and quick releases as bearing presses for hubs. It all comes across as easy, rewarding, and maybe even fun. It’s the kind of article that shop mechanics take with them into the bathroom so that customers don’t see them reading it, and it divides said mechanics into two groups: those who come out of the bathroom saying “why didn’t I think of that?” and those who come out saying “I was the first one to think of that.”

To me, it all makes sense, and I can read it and apply Zinn’s instructions with relative ease. That’s partly because I was obviously the first one to think of them, and partly because I’ve worked as a shop mechanic for the better part of ten years. However, I can still recall when I was reading those articles as a beginning cyclist, and trying to apply the instructions contained in them to my long-suffering KHS mountain bike. The result was my first foray into debt. As one bike shop manager replied, when I apologized for trying to work on my bike myself instead of bringing it to him, “Not at all. Home mechanics are our best customers.” Believe me when I say that bike shops all over the country are lighting candles in front of custom Zinn cranks as thanks for this article, not in the least because the hubs, bottom brackets, headsets, as well as the ceramic bearings that are being crushed I mean installed are about the highest of high-end product, and therefore the most expensive….

“Oh, it looks like you damaged the hub body when you tried pressing the bearing in at an angle. No, it can’t be machined. Yes, you can replace the hub, but we’ll need to cut the spokes out, which means we’ll need to rebuild the wheel. I suppose you can save the rim, but it won’t ever be the same, and with what you’ll be spending in labor, you may as well get a new wheel. I suppose you could always build it yourself….no? I don’t know, let me get my Mavic catalog. Oh, it looks like these wheels are only sold in front-rear sets….”

You get the idea….

PRACTICE MAKES PERFECT

Maybe you need to upgrade to ceramic bearings. Maybe you don’t. All I know is that sealed bearings need to be maintained like any other. If you have steel ones, and they feel rough, why not try to overhaul them first? Worst case scenario, you decide to upgrade to ceramics anyway, in which case you will have practice in how to overhaul sealed bearings. Because, yes, even sealed ceramic bearings need to be maintained; as Zinn mentions in his article, “SRAM recommends a service interval of 100 hours for the ceramic bearings in its Red crankset.” So for you, that means once every two weeks, right….?

STEP 1: REMOVING THE BEARING

For this, I really will refer you first of all to the manufacturer’s instructions, and second of all to Zinn’s article. However, I do mean “first of all to the manufacturer’s instructions.” Manuals are easy to find online, and if you have questions, there are always customer service staff sitting at their desks, tapping their pens and watching cycling.tv, who are ready to answer them, and occasionally even guide you through the process.

STEP 2: GATHERING YOUR MATERIALS

Here's what we'll be using. Yeah, yeah, I know. But you have to understand one thing: I wouldn't promote Finish Line products this shamelessly if I didn't think they were the best ones for the job.

You’ll notice what appears to be a dental tool lying alongside the grease gun. That is not a Finish Line product. Every shop mechanic has a species of tool belonging to the genus pointy. It can be a spoke that’s been sharpened on a grinder, a metal rod that’s been turned on a lathe, then sharpened on a grinder, or, in this case, a dental tool, which I find to possess a point of unparalleled sharpness.

Incidentally, Brett Fleming, the service manager of The Bike Gallery in Portland, Oregon, and unequivocally the best mechanic I’ve ever met, gives his mechanics a custom, hand-turned pointy tool when he feels they’ve earned it through consistent, quality work. Mine has sadly disappeared, or more likely been stolen. If it’s the latter, the mechanic who stole it will get his the next time he’s called upon to repair the internals of an older generation Rolf freehub body using a technique known only to Brett…

STEP 3: REMOVING THE SEAL

In addition to superior durability, sealed bearings, whether steel or ceramic, are designed to offer significantly smoother performance than loose or caged balls. As a result, your criterion for smoothness when you reach the end of the overhaul should be really high: you don’t want any roughness at all. Consoling yourself with a “good enough” isn’t acceptable.

Which is why you need to be really careful with this step, because it’s the only one in which you really stand to damage the bearing, in this case by damaging the seal so that it doesn’t seat correctly when you put it back on at the end.

What you’ll need to do, as carefully as possible, is insert your pointy tool between the outer circumference of the seal and the metal retainer of the seal, lift the seal out at that point, then simply slide the dental tool under the seal and around the outer circumference to lift the whole seal off.

It’s almost exactly the same method as inserting a tire lever under the bead of a tire, then running the lever around the circumference of the tire to get it off.

STEP 4: THE BEARING REVEALED

This is what the open bearing looks like. Most bearings have another plastic seal on the opposite side, in which case you may as well remove that, too. Some have a metal seal that can’t be removed.

You’ll notice that the bearing is not actually dirty. Because I am obsessive about keeping my bike clean and well-lubricated, I literally could not find a dirty bearing, at least not off of my bikes….

STEP 5: DEGREASING THE BEARING

Many shops will soak a bearing in a bath of degreaser, then blow it dry using an air compressor, also blowing any remaining dirt and grease out in the process.

Since I don’t have a compressor at home, I use Speed Clean. It’s a powerful degreaser with an equally powerful spray, and it also dries quickly, in only a couple of minutes, which is not the case with other degreasers.

And the drying part is important, especially for a sealed bearing, where you can’t really get at the internals with a rag. You don’t want any leftover degreaser in there, breaking down the fresh grease you just put in.

If you decide to use the bath method, use a degreaser like Multi, not Citrus; the latter might damage the plastic seals, which need to fit back in as tightly as possible.

STEP 6: THE BEARING CLEANED

STEP 7: GREASING THE BEARING

First, I like to use a grease gun to fill the gaps between the balls.

STEP 8: GREASING IT SOME MORE

Then, I like to put another layer of grease across the top of the bearing using my finger. Naturally, if you removed the seals on both sides, you would do this on both sides.

STEP 9: REPLACING THE SEAL

In keeping with the tire comparison we used earlier, this is much like seating the bead of a tire on a rim. Lay the seal on top of the bearing, then press down on it, moving along its circumference. You’ll feel the depressions along its inner and outer circumferences seat themselves in the metal retainer, much like the bead of a tire seating itself in the rim. Take a look to make sure there aren’t any bulges where it didn’t seat, and….

STEP 10

You’re done.

Put your finger through that hole, and give the bearing a spin to distribute the grease. Feel that? Now tell me: do you really need ceramic bearings?

And even if the answer’s yes, remember: ceramic bearings need love, too….

Here are links to the pages on the Finish Line website for the products I used or mentioned:

http://www.finishlineusa.com/products/speed-clean.htm

http://www.finishlineusa.com/products/degreaser.htm

http://www.finishlineusa.com/products/fortified-grease.htm

http://www.finishlineusa.com/products/grease-pump.htm

WHY I KEEP MENTIONING FINISH LINE PART 1

Seriously, it’s kind of a long story, but essentially what it comes down to is that I’m friends with Hank Krause, the owner of the company. He came into the first shop I worked at, only a couple of months after I’d been hired (see the second entry in this blog to find out what that was like), and when he saw me using Cross Country in the shop, walked over, told me who he was, and talked to me for an hour, much to the chagrin of The Owner.

Hank founded Finish Line in 1988, and in doing so, founded the category of bike-specific lubricants, degreasers, and greases, the so-called “maintenance products,” all when he could have been doing something much more lucrative with his time. Because the manufacture of Finish Line products didn’t require a CNC machine (or anodizing machine; it was the 80’s, after all), Hank and Finish Line never really got the recognition of a company like, say, Paul’s, but I don’t think that really bothered him, and he continued producing the best possible products with his usual humility and earnestness. He shaved his moustache….

Anyway, Hank and Finish Line gave me all the support I asked for at the different shops I’ve worked at over the years, whether by providing samples for events, replacing defective aerosol cans, or supporting teams, so now it’s time to reutrn the good will. For another take on why I'm doing this, take a look at my profile...

I’M OUT

Yesterday, when I turned onto the main road that runs through Dryden, I noticed that the street was glittering with broken glass. I rode through it, periodically dipping one hand down to clean the glass off my tires, figuring it would end in clean road again. Note to self: next time, wear gloves…. As I kept riding, I passed Rick, who had pulled over one of those tractor trailer dump trucks, and waved hello.

Moments later, the same truck passed me at highway speeds, spraying a seemingly endless, billowing cloud of the powdered glass out of its rear, and all over the road, and me. I stopped, not sure what to do, and then the sun came out, and the road turned diamonds. It was one of the most remarkable things I’ve ever seen.

I was right near a country road that I’d never taken before, so I turned onto that, and it took me into the high hills, where spring is still scrawling its name in lowercase flowers, and the air is filled with apple blossoms.

Stephan


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