So what about your Chain…? – Idaho Adventure Motorcycle Club

By Craig O. Olsen
Originally Published in the IAMC Newsletter, December 2010

… And no I am not talking about the one others pull to get your attention. I am talking about the one that makes the rear wheel on your bike go around. Without it you aren’t going anywhere. Neglect it long enough, and it can really bite you bad by suddenly failing (breaking) that leaves you stranded in a remote inaccessible area, causes your rear wheel to lock up resulting in a nasty crash, or does considerable damage to your engine when it balls up around the countershaft and front sprocket.

One reason why we may neglect our chains is that they are so reliable. They take tremendous abuse and consistently function well for thousands of miles. The links of all chains are connected together by a repeating series of pins inside of rollers cushioned by bushings, and these pins and rollers with bushings are subjected to continual pivoting as they pass the sprockets (countershaft front and rear wheel drive). This pivoting as the links pass a sprocket causes an eccentric wear on the inside of each pin and the outside of each roller bushing. Abrasive particles of dirt, mud and sand that get between the pins and roller bushings accelerate this wear. A sealed chain has small rubber rings (O-ring, X-ring, Z-ring …) at each pivot point that act to prevent abrasives from entering the pivoting joint and help hold chain lubricant within the joint. A well-maintained sealed chain provides less drag, requires less maintenance and lasts much longer than a non-sealed chain. It also costs more than a non-sealed chain.

Regardless of what type of chain you have on your bike, regular maintenance will make it perform better and last longer. Under normal conditions (riding on-road), a chain should be lubed about every 500 miles. If you ride offroad, lubricate your chain more frequently (at least every 200 miles). It makes sense to lubricate you chain when it is heated up (i.e. at the end of the ride rather than the beginning) so that the lubricant penetrates into the chain between the pin and roller plates and more quickly evaporates the solvent used in the lubricant. Leaving the lube on overnight or longer also helps it stick properly to the chain. This is recommended for sealed as well as non-sealed chains.

Put your bike on a stand and turn the wheel by hand while spraying the lube into the bottom chain run where it feeds onto the rear sprocket (vertical downward pointing red arrow below). Let it dry for a bit, then wipe off any excess with a cloth. Applying the lubricant on the inside of the chain helps prevent fling and will force it into the chain when you are riding. Also, apply lubricant directly onto the O-rings. The best way to do this is at the rear sprocket, spinning the wheel as you go (horizontal leftward pointing red arrow below). It is safer to do this the hard way, with the motor off and the bike in neutral.

A smaller amount of lubricant applied often is the key to good chain lubing, and proper application reduces fling off and waste. If too much is applied, it splatters everywhere: rear brakes, tire and fender. Put a rag on the other side of the chain to catch any overspray.

To properly lubricate your chain, it should be cleaned first. Apply a solvent (kerosene or a commercial chain cleaner spray) to the chain that is compatible with the rings of a sealed chain, let it stand for several minutes, and then wash off with water (garden hose or a wet rag). Avoid high-pressure sprayers at close range that might force water into the hinge point displacing the lubricant on a sealed chain. Often scrubbing the chain links with a coarse-bristled brush with the bike on a stand while turning the back wheel by hand is necessary prior to washing clean with water.

In addition to regular cleaning and lubrication, your chain also needs to be adjusted properly. While your owner’s manual will have exact requirements for your bike, the rule of thumb is about 1 to 1.5 inches of slack (moves freely up and down) at a point halfway between the two sprockets.

Chain slack is necessary because, as your swing arm moves up to compress for a bump, the chain gets tighter. When a chain is too tight, it will bind on the sprockets, causing quicker wear of both chain and sprockets. Over time, a tight chain will also ruin the countershaft and countershaft seal (the seal around the shaft that carries the front sprocket). Also, a tight chain is more likely to develop tight spots (caused by differential chain lengthening with binding between the links). A chain that is too loose may fly off the sprockets or slop in the driveline (lurching of the bike as the chain snaps tight following a short delay after twisting the throttle). Chain adjustments are very important, even though it may not be something you need to do very often.

With time and use, your chain will exceed the manufacturer’s wear limit and need to be replaced. This will be evident as the chain lengthens beyond a certain point. Remember, as the pins and roller bushings eccentrically wear (see the second paragraph above), more clearance occurs in the hinge point that results in the lengthening of the chain. A new chain will have a clearance of .0005 inches (1/6 the width of a human hair) between the pin and roller bushing. Most chain manufacturers limit chain wear to approximately .006 inches per link. For example, the standard chain pitch for a full-sized dirt bike is 5/8” (center-to-center distance between chain pins). Thus, if you multiply .006 inches by 100 links, the accumulated clearance is close to one full pitch (5/8 inches). Under these conditions, 99 links (or intervals) fit in the distance that 100 links were supposed to measure, and your chain is no longer good.

You can assess this wear by periodically measuring your chain. The easiest method is to stick a wrench between your chain and rear sprocket and rotating the rear wheel by hand until the top of the chain, along the top of the swing arm, is tight. Count 24 intervals between chain pins (It takes 25 pins to make 24 intervals.), and measure the distance center-to-center between the first and last pin. On a new chain, this measurement will be exactly 15 inches. If you measure more than 15-3/32 inches, it is time to get a new chain. Carefully inspect your sprockets when replacing your chain. A worn sprocket will only wear your new chain out quicker. For this reason, it is generally wise to replace your sprockets when purchasing a new chain.

References:

Canyon Chaser Motor Sport Touring, Chain Maintenance, http://www.canyonchasers.net/shop/generic/chain.php
Motor Cyclist Magazine, Chain Lube 101 What’s the Deal? http://www.motorcyclistonline.com/howto/122_ 0506_motorcycle_chain_lube/index.html
Web Bike World, 2010 Motorcycle Chain Lube Comparison, http://www.webbikeworld.com/t2/motorcyclechain- lube/chain-lubes-2010.htm
Web Bike World, Motorcycle Chain Cleaners Redux: How to Clean a Motorcycle Chain, http://www.webbikeworld.com/r3/motorcyclechain- cleaner/
Dirt Tricks, Measuring Chain Wear, http://www.dirttricks.com/Chain-Wear.htm
Cycle Connections Online Motorcycle Magazine, Tech Tips, Chain Maintenance, http://www.cycleconnections.com/articledetail. asp?TypeID=23&ID=117
Quality-Cycle.com, The truth about Motorcycle Chains! http://www.qualitycycle.com/truth_about_motorcycle_chains.htm
Thumper Talk, How to Properly Adjust Your Chain, http://www.thumpertalk.com/forum/showthread.php?t=406650
Motorcycle Consumer News, September 2001, MCN Rates Chain Lubes, http://www.mcnews.com/mcn/article_index.asp