It was time once again for that comedy of errors that I call routine maintenance. It's been about a year since I did a major tune-up on my main commuter, Champion, and It was getting to the point where I sensed that it was taking a little more effort to crank the pedals (and of course it's always the bike's fault, it can't possibly be the extra poundage that years of beer reviews and my recent obsession with gourmet food trucks have added to the waistline).
And then there is the temptation to let it go a while, since the last time that I found the effort to pedal had gotten more difficult, the extra energy expended helped me to quickly drop around seven pounds (but I soon could feel it taking it's toll on my knees as well, and decided that I would like to keep those around for awhile longer).
This time, besides the the usual adjusting and cleaning, I decided it would be a good idea to replace the ball bearings in my Shimano XT hubs as well, something I had never done before.
As usual I did a great deal of research before attempting this, not wanting to have to buy a new set of wheels right now. I watched all the YouTube videos I could find and read various books and blogs, I asked ask.com and queried how do I do this? At eHow.
Among the many sources I used, the information was all the same. Shimano hubs, including the XT hubs that I had on my bike, used loose ball bearings, not cartridge bearings as many of the newer hubs do, and the bearings in the rear are 1/4-inch, 9 on each side, the bearings in the front are 3/8-inch, 11 on each side. I also learned that to get to the bearings, I would need a cone wrench (which I already had, since you also need one to make adjustments to your hubs), and a regular box wrench or adjustable wrench. Since I had those, too, I was ready to go.
I planned to get the wheels out of the way first, then I would take the chain, gears, etc off to soak in degreaser while I cleaned up the frame a little. This time, I didn't feel It was necessary to remove the pedals and cranks as I had done this last year and replaced the bottom bracket at that time as well.
I figured the rear wheel would be the most difficult so decided to tackle that one first. I removed it from the bike, used a chain whip and cassette tool to remove the cassette (the gears), and was ready to disassemble the hub.
Since I have now been commuting by bike for five years, I have accumulated most of the tools that I need to do just about anything. I started out small, just doing the little stuff that I could do with regular tools, slowly adding some more specialized tools one at a time as I tackled each task and felt confident enough to add another repair to my repertoire.
Having assembled all the tools and parts I would need to overhaul my hubs, I grabbed the cone wrench and started to grab the adjustable wrench when I noticed that something was different from the photos in all the sources that I had scanned. In all that information, not one mentioned that the new Shimano hubs were somewhat different.
My hub does not use a cone wrench and an adjustable wrench, my hub uses a cone wrench and an allen wrench, which was no problem since I own an entire set of allen wrenches. But soon after this, the surprises kept coming.
I have had these wheels for probably a year and a half, so it's not like I have the newest, just-released technology that nobody else has encountered yet. It seems that the newest Shimano hubs, I am not sure about all of them, but definitely the XT's, the ones that are made in Malaysia rather than Japan, have some fairly significant differences, which I was soon to discover.
Luckily, when I first decided I would overhaul my hubs, I ordered a hundred each of 1/4-inch and 3/16-inch bearings. Sure, if your bearings are in good shape, you can just clean them, but bearings are cheap. If you are going to take your hubs apart anyway, you might as well replace them. I had my 1/4-inch bearings at the ready as I removed the cone (the thing that holds the bearing in place). The first thing I noticed was that technically the hubs still use loose bearings, but they are in a plastic holder. I removed the holder from the hub and thought, hmmmmm, these look smaller than the quarter-inch bearings that I have. The reason for this is that the new XT hubs have 3/16-inch bearings in both the front and the back. The non-drive side, which I was concentrating on first, takes 11 bearings which go into the plastic holder. The drive side, which doesn't have a plastic holder, takes 13 bearings.
I cleaned the cups and cones, re-greased everything, inserted the new bearings and reassembled the rear hub.
The front hub, which I had figured would be the easier one, turned out to be a little trickier. It was difficult to turn the bolts on one side without the other side turning. I was holding one side with my allen wrench, but needed the same size wrench to keep the other side from moving. Fortunately I have a Topeak Alien multi-tool which I carry on my commute that includes allen wrenches among its many tools, so I employed that to hold the other side. Without having three arms, this proved to be a little tricky. Most bike shops are equipped with an axle vice which holds one side while working on the other side, eliminating the need to have additional arms. I admit that I am a man of many vices, but axle vice is not one of them.
After cleaning and relubing the front, I started to reassemble it. This was when I discovered another difference in the newer hubs. When adjusting hubs, the golden rule has always been to leave just a tiny bit of play in the bearings because once it is clamped into place, the compression of the axle will tighten it up, eliminating the play in the bearings. Not anymore. The different structure of the newer hubs seems to have eliminated this step. After five or six tries, leaving just the tiniest bit of play in the hubs, clamping it into the frame did nothing to eliminate the play. Once I learned this fact, I adjusted the hub until it was just right off the bike, and it remained just right once mounted.
I removed the chain and left it to soak with the cassette in degreaser while I went to the store to pick up new inner cables for brakes and shifters as well as new brake pads. When I got back home, I started to put everything back together. I had everything back on the bike but the chain. I thought the chain was in pretty good shape. It hadn't been skipping or anything, but after soaking in the degreaser solution, which removed all of the gunk and loosened everything up, when I went to put it back on it didn't even come close to fitting on the teeth correctly. Generally, the gears and chain wear together, so that it is usually a good idea to change both unless you are very diligent about checking your chain wear and replacing it when necessary, but that didn't seem to be the case here. I think the large amount of buildup on the chain kept it together enough to prevent the gears from wearing out badly enough to need changing.
Anyway, it was obvious that I wasn't going be able to reuse this chain, so I had to go buy a new one. First, I went to the nearest bike shop, which is one that I don't really care for, but I'll buy parts there when I need to. This was on a Sunday, and this shop seems to be where most of the locals go to buy their kids' first bikes. I worked my way towards the service department, where the chains are at, dodging toddlers on training wheels on my way there. When it became obvious that I wasn't going to be helped anytime soon, I headed to the second closest bike shop. I was waited on promptly at this shop, so I got my chain, walked home and installed it.
Finally, I had the whole thing back together, took it for a test ride and everything seemed to be working fine.
At least next time I will remember how these new hubs work. As for the 1/4-inch bearings, a couple of my bikes have the old style hubs, so they won't go to waste.