Ah, winter. The infamous off-season for many motorcyclists. Even if the icy weather doesn’t allow for riding, I still find myself hanging out with the bikes in the garage anyway. This usually ends up with me identifying something that needs to be fixed. This time around, my focus was drawn to the drive chain on my 1994 Honda CBR900RR.
If you recall when I first wrote about this machine, I had rescued it from a life of neglect. Filth was collecting, tires were rotting, and fluids were turning black. The odometer had just over 40,000 miles on the clock. For many, this classic sportbike would have been considered “spent.” Not for me; I was going to return this bad boy to its former, rad-ass self. But, to accomplish that, it would mean I’d have to replace nearly everything that could possibly wear out.
Case in point: the drive chain.
It looked well-worn with surface rust collecting on the links. While not pretty, cosmetics weren’t what raised concern. No, what caught my attention was a “tight spot” in the chain. I observed this symptom while the rear wheel was raised off the ground and the engine was running in first gear (Doing such a task is the direct result of winter boredom, in case you were wondering). As the chain rotated, I could clearly see that the chain went from slack to tight with every revolution of the wheel. Not good.
Motorcycle chains can last 20,000 miles with regular maintenance. This bike had no service history, and I could only assume that its maintenance hadn’t been so regular. Regardless, once you have a tight spot in the chain, the only fix is to replace it with new. Changing out the chain might seem simple at first glance, but it can often be quite an involved repair. Don’t fear, I’m going to show you how take it on. Let’s get to it!
Getting The Goods
Before you start disassembling things, you want to make sure you have all the tools and parts to see the job through. At a minimum, you will need the following supplies:
- A new chain
- New front and rear sprockets
- A chain breaker and riveter tool set
- A caliper for measuring
“Wait, why do I need new sprockets?” you might wonder. Well, as with anything that has metal-on-metal contact, the friction between the sprockets and the chain rollers creates wear, and this sprocket wear pattern does not bode well if a new chain is suddenly thrown into the mix. If you don’t replace the sprockets, you may find that your new chain’s rollers will be eaten up well before their expected service life. Replacing the sprockets with the chain will ensure that these components will wear evenly together to reach their maximum lifespan.
Disassembly
With the rear wheel off the ground, I could start removing the decrepit drive chain. The first order of business was to undo the front sprocket bolt. Some bikes use a huge nut and lock washer to secure the sprocket, but on this CBR, it’s a puny little bolt.
In order to loosen this bolt, I needed to lock the front sprocket in place. Simply putting the bike in gear and using the engine’s compression wouldn’t provide enough resistance against loosening the bolt. I decided to resort to a specialized tool: a two-by-four wedged between the wheel spokes and the swingarm. This locked the rear wheel in place, which prevented the chain from moving, thus keeping the front sprocket from turning. Not pretty, but it worked without damaging anything.
Using a breaker bar, the bolt came loose without much of a fight. It is important to do this step before removing the chain as locking the rear wheel is your only sure-fire way of freeing a stubborn sprocket bolt or nut. With that done, it was time to separate the chain. The chain on this bike was of low-quality; a trait identifiable by the method in which the two ends of the chain are fastened together. The low-end fastening method I am referring to is the clip-style master link.
While this sort of master link fastener is adequate on low-power, smaller-displacement machines, it isn’t really the sort of setup you should be running on a big-bore sportbike. It’s not unheard of for the clip to come loose on the master link and then the whole chain comes apart. That sort of mishap can spell serious injury to yourself and the machine. The chain I’ll be replacing this with is known as an “endless” chain, which has a permanently-riveted master link, which, when installed correctly, cannot fail.
With the clip removed from the master link, I drove out the two pins that held the master link in place with the chain breaker tool.
With the chain disconnected, I could remove it from the motorcycle. Since I’m replacing the sprockets, I now needed to remove the rear wheel. However, it’s a good idea to crack loose the nuts on the rear sprocket while the wheel is still on the bike. To assist in freeing the stubborn nuts, I locked the wheel using the board-through-the-spokes trick once again.
With the sprocket nuts loosened, I removed the rear axle and pulled the rear wheel from the swing arm.
It felt pretty good removing this lot of grimy, worn-out parts.
Now, before we dive into installing the new parts, having the bike disassembled presents a perfect opportunity to give hidden areas a good cleaning. The front sprocket area and the swingarm were looking disgusting.
I’ve always felt that if you don’t clean things as you go, then you aren’t doing a thorough job. A little elbow grease goes a long way to make an old bike like this look fresh once again.
I like to compare the old parts against the new parts before reassembly. Looking at the photos below, it is clear why you want to install new sprockets when you replace the chain. You can see how the teeth on the old sprockets have become pointy, with wider valleys in between each tooth.
Reassembly
Alright, that’s enough scientific analysis. Time to get this thing back together. I first fitted up the new front sprocket to the bike’s engine and then mounted up the new rear sprocket to the rear wheel. Afterwards, I popped the rear wheel up into the swingarm and slid in the freshly-greased axle to hold the wheel in place.
I then strung the new chain from the rear sprocket to the front sprocket. While the directional orientation of the chain doesn’t really matter, I’m a bit OCD. I made sure the lettering on the chain links was right-side-up on the section that runs above the swingarm. It just looks better that way.
With the chain bridging the two sprockets, I could now pull the chain around the front sprocket. The objective here is to have the two ends of the chain meet on the rear sprocket. The rear sprocket teeth will act as a makeshift jig which allows you to more easily install the master link.
The first step in assembling the master link is to install the o-rings (which are included with the new chain) onto both ends of the chain. The purpose of these o-rings is to house grease that will lubricate the master link hinge points for the lifespan of the chain. You will need to lubricate four rubber o-rings with the grease that is supplied with the chain. Once these are thoroughly lubed, apply an o-ring to each side of both chain ends. With the o-rings in place, it is time to slide the master link into its spot by slotting the two pins into the receiving ends of the chain.
With the master link pins inserted into the ends of the chain, it is time to install the master link side plate. The side plate will need to be pressed onto the master link’s pins with the chain installation tool.
It’s important to not press the side plate on too far. It is critical to allow the master link to have the same level of flexibility as the rest of the links in the chain. However, you also want to make sure the side plate is pressed on enough so that the master link pins extrude far enough out the other side. To verify you have the side plate pressed on correctly, take a width measurement of an existing chain link, then compare that to your master link. They should have the same width, unless the chain’s instructions state otherwise.
With the master link width verified, it is now time proceed with staking (riveting) the master link pins against the side plate. This “mushrooming” of the ends of the master link pins creates a permanent mechanical fastener against the master link side plate.
I’m not going to lie, it takes a bit of muscle to stake the end of the pins. I had to put a cheater bar on the end of the tool’s crank lever in order to generate enough force to deform the end of the pins.
You’ll need to break out the measuring caliper to verify the “mushroomed” pin diameter is correct and in accordance to the chain manufacturer’s specifications. Too small a diameter and you risk the side plate slipping off. But, if you go too large, you could crack the pin.
With both pins properly staked, the chain will be permanently tied together, and the installation will be complete. That wasn’t too hard, now was it?
Before you go any further, be sure to tighten the front and rear sprocket bolts and nuts to their proper torque specifications. This can be accomplished by locking the rear wheel with the ol’ wood-through-the-spokes trick.
Now comes the fun part of setting proper chain slack and aligning the rear wheel. I’ve always found this to be the most fussy and time-consuming part of a chain replacement. There are a few tools out there that supposedly make these procedures less of a pain. Even with these tools, there is a large degree of guess-and-check employed.
I like to align the rear wheel first, then adjust the chain slack. This is because rear wheel alignment can be maintained while adjusting chain slack by simply turning the axle adjuster screws on each side of the swingarm in exacting increments.
I bought a tool for aligning the rear wheel and it is quite a simple device. The tool clamps squarely to the rear sprocket and a straight rod protrudes from it. The objective is to align the rod with the chain. If that condition is met, then your rear wheel is more or less straight in the swingarm. With the rod and chain aligned, you can lightly snug the rear wheel’s axle nut (But not too tight as the axle still needs to be able move fore and aft in the swingarm to allow for adjusting the chain slack).
To adjust the chain slack, grab a measuring caliper or a measuring tape. On the portion of the chain that runs below the swingarm, find the center point of the chain between the rear sprocket and the front sprocket. Press down on that spot of the chain. You will use that low spot of the chain as the starting point of your slack measurement. After you place a marker on your measuring tape for the chain’s low point, press the chain upwards until it stops. Calculate the total distance which the chain swings downwards and upwards. The result of this calculation is your chain slack measurement.
Based on what your bike’s specifications are, you may need to increase or decrease this slack measurement. To increase it, the rear wheel will need to move forward in the swingarm (toward the engine). To decrease the slack, the rear wheel will need to move backward in the swing arm (away from the engine). Small increments should be made to each swingarm axle adjuster screw to hone in on the correct chain slack measurement while maintaining correct wheel alignment.
This procedure will take a while to perfect, but the more you do it, the quicker it will become. Eventually, you will get the correct chain slack and the rear wheel will be aligned. Once you have that done, torque the rear axle nut to specification and apply some chain lube to the new chain to finish off the job. Now go grab a cold beverage. You’ve earned it.
The Figures
Parts Cost: $175.00
Tools Cost: $60
Labor Hours: 6
Looking And Feeling Good
The cost of this repair is highly dependent on the kind of bike you ride and the quality of parts used. A full-on sportbike can run close to $250, while a dual-sport might only set you back around $130. The time it takes to complete the job could vary greatly as well, depending on your wrenching experience level and on how much you want to clean your bike along the way.
Replacing the drive chain is one of those maintenance items that can be accomplished by any budding motorcycling DIYer. A minimal number of specialized tools are required to complete the job. Few repairs result in such a rewarding change in your bike’s appearance. If your chain is on its way out, a new one may make your bike ride down the road smoother and quieter.
If you’re like me and find yourself unable to ride during these winter months, consider giving your trusty bike a thorough look over. Who knows, you may discover your drive chain needs some love. As for this classic CBR, a new chain is just one more project checked off the list on its road to redemption.