This is the forum for the nerdy stuff about motorcycles and scooters. I will be posting ongoing articles to help you understand various systems on your bikes and why they get cranky every now and then. Please keep posts on this topic.
Jan 5, 2017
The motorcycle chain is one of the most neglected parts on the bike until something goes wrong one day. That something is the chain snaps and leaves you stranded and waiting for a tow. That is an inconvenience but a chain break could distract you with a sudden loss in power, damage the bike and cause you to lose control. That would be a bad day. The good news is that it doesn't have to go down that way if you understand the care and feeding of your chain. Yep, it's all about maintenance. If you ride during our rainy season, water on the road takes its toll on your chain and it is not about just rust. When it rains the water mixes with whatever is on the road which is a mixture of chemicals called pollution, dust which is abrasive. The water forms a slurry that gets into the chain and breaks down whatever lube you have on the surface of the chain. Chains by design are internally lubricated. Chains are constructed of link plates, pins, bushings and rollers. In order for a chain to roll around a sprocket the pins must have clearance through the bushing holes allowing them to pivot. That clearance begins at about .0005", or 1/6 of a human hair. The pins and bushings are subjected to continual pivoting, and as they pass a sprocket, steel against steel wear occurs. This causes the pins and their mating holes to wear in an eccentric manner as the diagram below shows. In abrasive conditions (and especially mud) grains of sand are introduced between these mating surfaces and wear is accelerated many times over. A sealed chain (O-ring, X-ring, Z-ring ...) acts to prevent abrasives from entering this pivoting joint and also holds minute amounts of high performance grease to minimize wear. Without periodic maintenance, the chain becomes devoid of any external lubrication and protection. Lube even acts as a sun screen to protect the delicate seals from the effects of the sun. Lube reduces the natural break down of rubbers due to outgassing of plastizers that keep them flexible. Within a period of months the seals start to crack and break down and will soon fail. One thing that I outline in my classes is what the weak links are on your bike and rubber is high on the list of weak actors. With the seal now compromised the internal lubricant now starts to seep out and dirt starts to migrate in. Wear increases exponentially and most chain manufacturers limit chain wear to approximately .006" per link. If you take that number and multiply it by 100 links, the accumulated clearance, which some refer to as stretch is close to a full pitch or 5/8". So if 99 spaces fit in the distance that 100 spaces were suppose to measure, your chain is done. Here comes the painful part, good chains are not cheap. OEM chains from a dealer can cost upwards of $200+. You don't have to buy an OEM chain in fact most manufacturers don't make them but label products made by two of the most prominent makers of chain DID and RK chains. There are a host of other specialty and aftermarket manufacturers to also choose from. Many of these chains can be purchased around $112 or less. But who wants to be spending this every year or so and what can be done to maximize the life of the part in such a hostile environment? Simple, just clean, lubricate, inspect and adjust your chain as needed every 600 miles or thereabouts. The procedure for most bikes only takes about less than 20 minutes. You do have to be careful as there is a way to do it wrong and make matters worse. You have to exercise care in what you use to clean and lubricate as there are products that can attack the rubber seals embedded in your chain. Avoid so called lubes like WD40 which can actually damage seals because they have a large proportion of their contents are actually petroleum distillates which is a general description solvents, emulsifiers which can break down rubber. Only a small percentage of WD40 is actually lubricant. You can buy dedicated chain lube and cleaners from Motul or Bel_Ray. These can get kinda pricey for the amount of product that you get. You can use a general purpose lube that you can use on your chain and cables such as LPS and Tri-flow. These you can buy at Ace Hardware or from Locksmiths and of course online. The cleaners are actually mild solvents that dissolve old grease and disperse dirt but without harming the o-rings. WD40 does make a product that I like which is their white lithium grease. It's cheap and can be used on chains and side stands. I will be outlining the procedure which is quite simple in a future post.