Showing the drivetrain some love

May 6, 2022

Something to do on a dreary rainy day

IT'S A WET, COOL, UNAPPEALING SORT OF DAY for a ride, and tomorrow is supposed to be the same only more so. That leaves me with time on my hands. What to do for amusement?

On my recent overnight camping trip I noticed (could not HELP but notice, actually) that the chain is beginning to skip when under heavy load, in certain gears. That, along with sloppy and imprecise shifting, is a sure sign that the chain has stretched and the cassette has begun to wear, to the point where the best and only solution is to replace them.

Prudence dictates that the chainrings should also be replaced, so that all of the moving parts will have the same degree of wear and will function smoothly as a unit when you need them to (which of course is ALL the time.)

Demonstrable proof, for anyone who doubts chain stretch is a real thing. Old chain above, new chain below. The tiles are 12 inches square; note how much the rivet on the old chain is displaced relative to the new, at the tile boundary.

This is maintenance I had planned / hoped to defer for another month or so but really now is as good a time as any. Owing to other time commitments I won't be riding much in the next ten days or so anyhow, and whatever riding I do can be done on my road bike instead of Odysseus, thereby basically making it a moot point as to whether I do this maintenance today or a month from today.

Knowing that this day was coming, over the winter I spent time (and cash) accumulating all of the necessary bits and bobs that I didn't already have on hand from decades of do-it-myself bike maintenance. All of the items I planned to replace were sourced and ordered; everything was in hand by late December and has been sitting on my workbench, waiting for today to arrive.

New bits awaiting installation: 50, 39, and 30 tooth chain rings, new Capreo-specific 9 speed cassette (9-26), new 9 speed chain.

To begin, I broke out my on-the-road tool kit as well as a few specialty tools that will not make the trip with me.

These tools will travel with me. They include 4, 5, and 6 mm hex keys, the Capreo cassette lockring tool, a chain stretch measurement tool (which will probably not make the trip), a pair of pliers, a small multi tool that includes a chain rivet driver, a small flat-blade screwdriver, a good spoke wrench, and my homemade chain retaining tool. I also carry some nitrile gloves to reduce the amount of grease I'll get on my hands. Also staying home is the plastic tool that removes the dust cap from the cranks (it's that round black thingy between the pliers and the lock ring tool.)

Not going with me is the very VERY handy master link "pliers" tool, that makes separating the two halves of the master link a literal "snap". I used it today, though.

Also staying behind is my chain whip, which came in handy when I was taking the lock ring off the cassette. I don't expect / plan to take the lock ring off while I'm on the side of the road; if it's needed at all I'll have the lock ring tool handy in case the bike shop doesn't (the Capreo cassette is an older design and wasn't widely used even before it was phased out), but any (EVERY) bike shop ought to have multiple chain whips on their tool board.

The first step was to remove the master link and then dismount the chain. I have a couple homemade "chain keeper" tools that help with this task. They're nothing more than a piece from a broken spoke (made of nice, STIFF stainless steel wire), bent at the ends and with a loop in the middle. The bends at the ends go into links far enough from the master link that it creates a nice slack section, making it easy to unsnap the master link and remove it.

The chain keeper in place, before I split the master link. It makes it easy to create some chain slack without having to constantly fight the spring action of the rear derailleur.

It also keeps the chain from immediately whipping around once the master link has been removed.

Once the master link was removed it was easy to remove the chain from the bike: just unhook the chain keeper and let nature take its course.

Next, the back wheel came off and the skewer was removed to make it easy to check the state of the bearings. As I spun the wheel I could feel some slight binding in the bearings, meaning that at a minimum the cones needed a slight adjustment. (My hub set is Shimano 105 dating back to 2007, with traditional "old fashioned" cup-and-cone bearings.)

In reality, they were long overdue for a thorough service: remove the bearings, clean the cup and cone surfaces, clean the bearings themselves, and reassemble with new grease. This was a task I was hoping to avoid but my sense of "proper maintenance" was talking inside my head, saying "Don't be a lazy fool. You know you need to do this, so don't be such a putz. Just DO it, already. If you don't you're sure to pay the price later on, and it probably won't be in the comfort and convenience of your home workshop. Do you REALLY want to risk a breakdown on the road somewhere because you cut a corner you know damn good and well should not be cut, just because you're a lazy sod?"

Suitably chastised by my mechanical conscience, I decided to take care of the bearings as I knew I should.

Before doing that, though, since I already had the wheel mounted in my truing stand I went around and checked the tension on all the spokes. The wheel was still nicely trued but several of the left (non-drive) side spokes were suspiciously loose- almost, but not quite, slack. I've been hearing curious periodic "plinking" noises while I ride and I'm wondering whether this may have been the cause. So, it was out with my spoke wrench to make some small adjustments to the tension on those spokes. They're all nicely snug now and the wheel is still true so I'm satisfied.

Having put it off as long as I could, I did the rear wheel bearing service. I followed the procedures described in this video (with whose creation I had nothing to do; all due credit to those who wrote, directed, produced, edited, and performed in the video and none to me).

That's a nice, neat, well-organized tool board in the background, unlike the mess in my shop. I do kinda wonder why he has THREE of what looks like the same size Park spoke wrench and no other sizes. but maybe this is a home shop and that size is the only one he needs at the moment...

Servicing the bearings meant another trip to my tool board, to fetch the cone wrenches necessary to get at the bearings themselves.

It's important to keep track of what goes where, or the axle doesn't fit correctly when the bearings are reassembled. This is the non-drive side, showing (from L to R) the outer end of the cone, a spacer, and the lock nut that holds everything in place and presses against the inside of the dropout.

That task done, it was time to move on to replacing the chain rings. Once again, I relied on instructions from the all-knowing Interweb to do this job, because this crank design post-dates anything I have worked on in the past. As with the hub maintenance video, I claim no credit for the video presented here, and direct all credit to the rightful parties.

Reiterating a couple points from the video: it's absolutely essential to get that little plastic tab thingy lifted before trying to pull the left crank arm off. Once that's done the crank arm comes off easily (assuming you've loosened the pinch bolts).

You can clearly see the plastic tab in its raised position.

Since the bottom bracket on my bike is very clearly marked "DO NOT DISASSEMBLE", I didn't.

Once the crank was free of the frame it was no trouble at all to replace the chain rings. The smallest one is held on with five hex head cap screws that screw directly into the spider. The middle and large rings are held on with five additional cap screws, which thread into threaded sleeves that insert from the "back" of the middle ring. This type of fastener has been around for at least fifty years.

New chain rings installed and ready to reassemble. That little round gizmo goes between the left crank arm and the bottom bracket shell.

With new chain rings in place, I reassembled the cranks as shown in the video.

Shimano are very clear about how, and how much, to tighten the pinch bolts that secure the crank arm to the splines.

My handy-dandy 1/4" drive torque wrench, with the 5mm hex key attached, is the right tool for the job.

Once the crank was secured, the dust cap went back in place as per the cautionary note in the video about crank service. It'd be BAD to have the crank fall off while I was riding! And, the little plastic lock / retainer tab has been lowered into position.

Next up it was time to reinstall the rear wheel and the new chain. With the wheel correctly seated and secured, I needed to know how much chain to use. I counted the links on the old chain, and compared its (stretched) length to the length of the new chain. I counted a suitable number of links along the new chain and removed the rest. Rather than use my on-the-road rivet driver I used the much better bike shop professional grade version I have on the tool board.

This is one of those tools for which there is no substitute, and where a good quality tool makes a WORLD of difference. I don't know of a better one than this, but it's too heavy to take with me so I'll rely on the small one on my multi tool (hoping that I will not need it).

The links I removed in order to make the new chain the proper length will travel with me, along with the master link that I salvaged from the old chain. They'll go into a small empty pill bottle to make them easy to find and keep them clean.

A lube of the chain followed by quick run-through of the gears up and down the cassette, with the necessary adjustments to get everything lined up and running/shifting smoothly, meant the drivetrain had been shown all due love.

The only thing left now is to service the bearings in the front hub, which I'll do tomorrow since the rain and cool temperatures will still be with us; I'll wait a while yet before changing the tires to the ones that will make the trip with me.

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Jill PembertonKeith - 4 Stevens Court is cheering for you!! Xoxo Mark, Jill, Morgan and Taylor:). Enjoy your journey:)
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2 years ago

Keith AdamsTo Jill PembertonThanks Jill!
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2 years ago