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Dirty hub, pre-cleaning, right after the axle was removed.
January 18, 2013 |
Although it will be a little while before I can accumulate enough funds to build the wheels I have planned for my Fuji, I can still enjoy the process of prepping what I do have--the hubs--so that when the money is ready I can start quickly. I also figure this will be a good place to go deeper into hubs, as I sort of glazed over that step in my
previous post about my first solo wheel build.
I have an odd affinity for hubs. They hold a strange place in the bicycle mythos. They are important, yet often overlooked; they are very utilitarian yet can be very beautiful. I already mentioned my tastes in hubs in the previous post, but I'll recount it here. I love old hubs, especially hubs with high flanges and bold curves. The more narrow the hub shell, and higher the flange, the more I'll probably like the hub. A gentle concave curve connecting the two seals the deal.
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Hub diagram. Hand drawn.
January 19, 2013 |
In addition to enjoying their aesthetic, I also enjoy working on hubs. Overhauling a hub is something I almost always enjoy, especially if the hub starts off being very nasty and dirty. I love taking out the axle, reading the story the bearings may or may not tell, cleaning everything, and putting it all back together into a clean, smooth state of operation again. It can be very fulfilling. One of the first things that was handed to me as a fresh and learning bike mechanic was a wheel with a loose hub. My manager explained the process of adjustment, and handed it to me. I probably sat with that wheel in my lap, constantly tightening and loosening the cones and locknuts, for about an hour. Frustrated, I handed the wheel to my manager and asked if it was acceptable. Without saying anything, he loosened the locknuts, hand tightened the cones and gave it back to me. "Like this," he said. It was buttery smooth and had no play, or side-to-side wobble. Of course it had to be tightened (that is the tricky part), but I was irritated that I was struggling so much with something apparently so simple. I remember making some comment about taking an example home to practice so that I could get the procedure down, and my manager firmly responded that I was not paid enough to ever "take anything home." And so I never did.
Ah, but to those who aren't familiar with the inner workings of bicycle brackets, some of the above terms such as cone and locknut probably didn't make a ton of sense. I'll explain. A bicycle bracket--the hub on each wheel, the headset, and the bottom bracket--is essentially a bearing assembly that allows an axle or spindle to spin. The hubs let your wheels roll along the ground, the headset lets you turn your handlebars, and the bottom bracket lets you turn the crank when you pedal. Although they are each a little different (the headset usually being the most different) they all operate on the same principles and share the same parts, in concept. I'll explain in the context of a hub, as the terminology does change a little depending on which bracket you're dealing with.
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Inner Hub Diagram. Hand Drawn.
January 23, 2013 |
On each en
d of the hub you have an inward-facing cup, where a ring of bearings rests. Running through that ring of bearings will be your axle, which towards each end will have a cone: in essence a nut with a concave machined surface on the outward rim, which allows the axle to roll on the bearings. Behind the cone you can sometimes have a washer, spacer, or two, and then finally a locknut, which is tightened to lock the whole assembly together.
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The axle, bearings, and hardware from my hub, pre-cleaning. I regretfully
forgot to photograph the disassembled parts after their cleaning, but this will
do to show some real life examples. Note the concave surfaces on the cones, and the
washer-spacer combo between the locknut and cone.
January 18, 2013 |
A properly adjusted hub will allow the axle to spin freely and fluidly, yet have absolutely no play. A loosely adjusted hub will definitely allow the axle to spin freely, but you'll be able to move the axle side-to-side and maybe even up and down within the assembly. This means that there is space between the bearings and either the cup or the concave surface of the cone. As you ride on a loosely adjusted hub, that play will deform the cup and cone surfaces so that they are no longer smooth, and may even deform the precise concave curve necessary for the bearings to roll. Give it enough time, and you can even deform the bearings, turning them into misshapen little lumps of steel. A hub that is adjusted too tight will make it difficult to turn the axle, and over time the same damage can occur--rough surfaces and disfigured bearings. Properly adjusted hubs--in addition to all your brackets--are a very important yet often overlooked form of bicycle maintenance that
needs to be kept up on.
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Close up of the stamped lettering. Note the 6 and 80, which I believe designates the
hub being made in June of 1980.
January 23, 2013 |
Now, onto my hub. The 1980 Fuji S12-S came stock with a pair of SunShine Gyro-Master hubs. Interestingly, a Google search on any information on these hubs tends to only bring up sealed bearing BMX hubs from the mid '80's. Indeed, I've never come across any SunShine hubs as a mechanic, at least any that I've noticed. Regardless, I think they are very pretty and I rather enjoy the look of mine. I noticed something interesting on my hubs. Beneath the SunShine logo, "6 80" is stamped into the aluminum. The "6" looks obviously stamped at a different time from the "80", and both numbers appear to not quite line up with the rest of the lettering. I know the frame of my Fuji was made in July of 1980. I would wager this stamp means the hub was made in June of 1980. I love that I can pinpoint when the parts of my bike were actually manufactured!
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SunShine Gyro-Master front hub, still laced to the original rim and uncleaned. Note the nasty, dried
grease on and around the dust cover.
January 18, 2013 |
The hubs, and indeed the whole wheels, that accompany the bike came to me very dirty, with old gritty grease and corrosion covering much of the hub surface. I was anxious to see how much, if any, shine was beneath all of the grime. After unlacing the wheel, I took the bare hub and disassembled the inner workings on my kitchen floor. The very top picture of this post shows what it looked like after I opened it up: nasty, reddish brown grease, one of my least favorites to find. I hand cleaned everything the best I could with paper towels, and took the parts into work with me the next day to use our parts cleaner. As I've mentioned in a few previous posts, we have an ultrasonic parts cleaner where I work at REI, and that does a pretty good job of getting a lot of that old, dried grime off. I popped my parts in with a coworker who was cleaning some of his own parts (a disassembled crank), and after a few bouts everything came out looking very good. There was shine underneath all of that dirt!
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Left: Hub shell before cleaning and polishing. January 18, 2013
Right: Hub shell after cleaning and polishing. Wow! January 25, 2013 |
A lot, if not most or all, of the high powers of bicycle knowledge out there will tell you to never reuse the original bearings if you're overhauling a hub, or any bracket for that matter. This is, in all truth, sound knowledge, as bearings can lose their integrity and roundness over time. However, some of the first bicycle work I ever did involved me and my dad overhauling the headset on my newly acquired
Cannondale SR500. I remember my dad telling me that you were to always inspect the bearing surface for any cracks, dents, or other marring Looking through a magnified eyepiece--much like the stereotypical jeweler appraising a fine gem--I remember he and I looking at the tiny bearings that came out of my headset. We determined they were fine enough to reuse, and they are the bearings that are still in there today. I'm not allowed to--and I don't--reuse bearings at my job now at REI, but I have no problem doing that for myself. Small, silly traditions are helpful for keeping connections alive inside of our souls.
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Left: Outside of hub assembly before cleaning. January 18, 2013
Right: Outside of hub assembly after cleaning. Shiny! January 25, 2013 |
One night I sat down at my computer desk to reassemble the hub. I had my newly cleaned parts, the original bearings (which looked great by the way), and all of the appropriate tools, including one of my precious tubes of Phil Waterproof Grease. A few words on grease: it's important. Way more important, in my opinion, than the lube which goes on your chain and cables. That stuff will eventually come off, be it from wind, water, or time. It's natural. Grease stays
inside of your bike for a long time, and helps it perform it's most basic bicycle functions: turning, pedaling, and rolling along the ground. Personally, I've only ever used two of the products out there: Phil Waterproof Grease, and Park Tool's Poly-Lube Grease. Between the two, I much prefer Phil's grease. It's thicker, and heavier, and easier to use in my opinion. The Park Tool grease is slimier and thinner feeling. It feels cheap. I nabbed a few tubes of Phil Waterproof Grease before I left Indiana. I got these tubes in a slightly amusing manner.
While working at Ike's Bikes in Richmond, Indiana, my first job as a bike mechanic, we got a call one day that an older store that used to sell bicycle equipment was wanting to give us all of their old new stock. The store mentioned was Veach's, a name that should spark quiet excitement in most anyone raised in Richmond from the past several decades. A very old store, Veach's is mostly loved and revered as an "old fashioned" toy store, one where you can find figurines, dolls, model kits and other more "wholesome" play-things. Early in my own life, the toys were still in the basement of the store, while the first floor housed an assortment of odds and ends. There was always great excitement when we would visit Veach's with my grandparents, and one of my earliest memories is standing in the basement of that store getting a birthday present. Sometime during my early childhood, the store dropped the "five and dime store" act on the ground floor and became a full-blown toy store, which is what it still is today. At some point I guess they sold bike parts and accessories, maybe even a few bikes. They ended up giving us all of the stuff they never managed to sell, most of it coming from the late '80's or early '90's if I had to guess. A lot of it was relatively useless, out-of-date and cheap crap. But some of it was still useful, and each of us three mechanics divvied up the tubes of Phil grease for our own personal stashes. I got three tubes out of it, which should last me a good while.
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Left: Preparing to assemble the second and last bearing assembly.
Top Right: Phil Waterproof Grease, still with the Veach's price tag for
$2.00 (it retails for about $10 now)
Middle Right: Greased cups, ready for bearings.
Bottom Right: Bearings resting in the greased cup, ready for the axle and cone to be
installed. Note the ring they form in the cup.
All taken January 23, 2013 |
I spread the grease on the inside of one of the cups with my finger, leaving a thin but substantial layer. Then, I placed half of the bearings, nine of them, in a ring around the cup. The thick, sticky qualities of Phil Waterproof Grease doesn't make this hard to do. I then spread another thin layer of grease on top of the bearings, and gently coated the concave surface of the cone; the part that would contact the bearing surfaces. The cone itself was tightened against the locknut and spacers on the axle, ready to interface with the bearings. After I popped the dustcap into place--a thin, lipped ring of metal that protects the grease inside from, you guessed it, dust and dirt--I slid the axle-cone assembly in, and flipped the hub around. One side was done.
Now, normally I'm doing this to a hub that is laced to a wheel, so when I flip the hub around, I can rest the axle on a surface, and the wheel can lean slightly to one side while I wrap up the job on the unfinished side. Doing this kind of work to a lone hub is actually kind of an awkward process, but I managed to carefully balance the hub on the axle. Probably not the smartest option, but it was kind of cool and worked out for me. At this point I basically repeated the steps on this side of the hub, and sealed the deal with the cone, spacer, washer, and locknut. Now comes the adjustment.
As explained above, hub adjustment is important. It can also be a bit tricky. Hand tightening the cones to the proper positions isn't that hard, it's the procedure of tightening them against the locknuts that almost always screws up the adjustment. This happens because as you secure the cone, and turn the locknut to tighten the assembly, the axle virtually always spins with it, at least a little bit, thus eliminating the position your cone was in. There's two ways to deal with this, and honestly one way is the "right" way, and one way is the "not-so-right" way.
The "right" way, which I do at work, involves an axle vise. This is a special tool inserted into a vice, which allows you to clamp onto an axle without damaging the threads. With the axle secure, you can then make your adjustment and tighten the assembly without fear of the cone position changing. It is still a little tricky, as I find the position awkward, but it does usually make it a lot easier. The "not-so-right" way, which I learned in Indiana and use on my own bikes, is to actually over-tighten the cone first, so that then when you tighten it against the locknut and the axle turns too, you are actually loosening it to (hopefully) an adequate adjustment. It doesn't always work, and can be frustrating to find that proper amount of over-tightness. But it works well when you don't have an axle vise. If there is still just a hair of play in the adjustment, another trick is to secure the first locknut, and then tighten the second. Again, it is a bit of a messy fix, but you are essentially compressing the whole assembly at that point. This way you can nudge the cones together without starting over again. These "not-so-right" procedures are what I did to my hub here.
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The inked lettering. The "r" in "master" would not hold the ink, it is a shallow letter.
Probably a sign of the less-than-highest quality of the hubs.
January 25, 2013 |
The final step is purely a cosmetic one, and a trick that I learned from a coworker who also has a fondness for old bicycle parts. He showed me how you can use a Sharpie to ink the stamped lettering on old parts, and then use rubbing alcohol to wipe away the excess, leaving the black ink in the recessed letters. It really helps the lettering pop and be readable. The "r" and part of the "e" in "master" were difficult to keep the ink in, due to the recessed lines being very shallow. More than likely this was because the stamp for "GYRO-master" did not firmly press into the right side, no doubt a sign of how these hubs aren't the highest quality parts out there. No matter to me, I think it looks great.
With all of that said and done, the hub is now ready to be measured to determine spoke length for the future wheel build. It won't be the next wheel I build, I am going to build a rear wheel for Keri's bike, but it will probably come after that. I can't wait.
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Another close up of the inked lettering. I love how the "R" snakes below the "O".
January 25, 2013 |
Note: As you may have noticed, I provided two illustrations to demonstrate mechanical diagrams that would have been otherwise difficult or impossible to photograph myself. Wanting to keep as much material original as possible on my blog, and to also stretch my lazy drawing muscle, I found this to be a fun alternative. If you liked the drawings, or would prefer less-crappy diagrams from a professional source, let me know in the comments. I'm anxious to hear some input.