® Powersports Drive Chains

This is a consumer video I did for Kawasaki. Just a few simple pointers on the proper care of a motorcycle drive chain.
The student didn't show for class one day, but the next day he was back, with his hand bandaged up. The class was an advanced course in engine building and performance modifications for motorcycles, snowmobiles and personal watercraft. The year was 1988, the school Motorcycle Mechanics Institute, and I was an instructor. He was a quiet student so I thought to generate some conversation by asking him what happened to his hand. Reluctantly, he. began to tell a story of having been working on his motorcycle at home and when he went to lubricate his drive chain, he actually cut the ends of two of his fingers off! I was sure that I hadn't heard him correctly. This was an advanced student in his 10th month of training at MMI. Did he mean that he was *running* the engine while he lubed his chain!? He did and he was!

As simple as this part of a powersports vehicle seems to be, you would think that proper drive chain selection, maintenance and, ah, safety would be well understood by now. But this is not the case. There is nearly as much misunderstanding and misinformation regarding chains as about anything in powersports, and probably more.

Powersports final drive chains are amazing. Few parts on a motorcycle have had to withstand the power increases that chains have. Think of it. Bikes actually started with leather belt drive. There were no clutches, the rider had to jump off the machine at a stop. Of course, chains quickly became standard, but even into the 1950s there were few motorcycles developing more than 30 crankshaft horsepower. And now? There is not enough room in the average garage for one of every factory-stock model that can claim 150 hp or better. And yet the drive chain doesn't seem to have changed that much, at least visually.

But of course it has. Only the cheapest of today's final drive chains have split rollers, for example. Chains marketed off of bulk rolls and those with sintered metal rollers are almost extinct, thankfully. Half links have disappeared, and chain breakage on bikes that could barely get out of their own way is a thing of the distant past. And despite lasting longer than ever before, drive chains are increasingly smaller and lighter, yet stronger too. Not surprisingly, they are also priced accordingly; they are quite literally ultra high performing parts. One thing has remained the same though, riders are *still* not maintaining their drive chains correctly, getting on average only 5,000 miles out of a street bike chain when they should get three times that. They don't lube them properly, they don't adjust them properly, and they subject them to conditions that should never happen, such as high-pressure washers.

A drive chain is designed to be lubricated at the sideplate-to-sideplate junction, and nowhere else. Don't lube the rollers, and don't lube the sprocket. Lube the lower run of the chain, not the upper, so that the lubricant is forced into the chain (by centrifugal force) before it can be flung off, and do your lubing after riding, not before, while the chain is still warm. And yes, o-ring chains need lubrication! The only thing o-rings do is keep one thing out and another in. They keep crud (dirt and water) out, and they keep precious lube in, reducing rust- and dirt-related wear and extending the chain's lubrication interval by as much as 50 percent. That's all. O-ring chains are*not* by any stretch of the imagination lifetime-lubed chains.

Speaking of water, never deliberately spray water, especially high-pressure water, onto your drive chain. It is a certain way to kill it. Even steady use in rain cuts the chain's life short. Most riders also over-tighten their drive chains. The amount of slack needed in your chain isn't necessarily intuitive and varies with each model motorcycle. Your owner's manual is a good starting point, because its spec takes into account the angle of the bike's swingarm and the weight capacity of the machine, both important factors. Obviously, if the bike is modified, with a different swingarm, measurably different tires, suspension modifications, etc., a change from factory spec will be necessary. But be careful. If you have to err, err on the loose side. It is far better for the chain to be too loose than it is for it to be too tight. Too tight a drive chain tears up engine and wheel bearings, not to mention sprockets. Finally, look out for chain wear. A quick and surprisingly effective test, and one pro techs use, is to gather up the slack on the chain's bottom run with one hand, and with the other attempt to pull the chain from the back of the sprocket. A new chain does not budge. As it wears however, the chain will lift from the sprocket more and more. When it gets to the point that the root of the sprocket's tooth is visible, the chain is worn out and needs replacing. Failure to do so at this point will inevitably trash the sprocket. Also look out for kinking, which if the chain is high quality points to lack of lubrication. Kinking and rust can be temporarily overcome with copious lubing, but in reality the chain will become even harder to live with and actually more dangerous than it was, stretchiing like crazy and continously needing readjustment. Replace it instead.

Large bore street bike manufacturers source their chains in "continuous" configuration, meaning they are already manufactured in a loop. The chains are therefore installed at the factory before the swingarm is mounted, and the OEM service manuals also reflect this, specifying the same procedure for in-service replacement. A "flat rate" tech can of course beat the system by disconnecting the chain and reconnecting it, instead of removing and replacing the swingarm, but the bikes' manufacturers frown on this. All the same, most replacement drive chains are not factory, mostly because of the factory's higher cost, and these chains are not sold in loop form, but un-looped and with a master link. This is acceptable, if done correctly.

Here are some interesting facts about drive chains. First, there are three kinds of master links. The traditional clip type is rarely if ever found as original equipment on large bore street bikes, for good reason. High power output and slip-fit master links don't go together. Even the aftermarket chains sold for these same bikes have *press-fit*, stake-type master links, the second and most proliferate type. The third type of master link is that which comes on the bike from the factory. This is not commonly thought of as a master link, and isn't really in the traditional sense. But it is in fact a master link. How else could a run of chain be rolled into a loop? One of the links in any "continuous" type chain will be found to be different from the rest. Some, but not all, chain makers actually color it slightly differently. It is the link installed by the chain manufacturer before it was shipped to the vehicle manufacturer. Like the master link in the aftermarket chain, this link's outside plate is a very tight, press fit, for the added strength 200 hp machines require. However, the factory's master link is not designed to be self-installed. Second, nearly any lubricant is better than none at all, but some are obviously preferred. Many modern aerosol lubes go on thin and then gell up, and this seems a good thing for the chain. Don't rely on WD40 or engine oil. Most importantly, lube regularly. Every 500-600 miles is a good plan.

Most that can be said about drive chains is also true of modern powersports engine cam chains. They're made by the same manufacturers, they arrive in looped form, they have what are technically, but not conventionally, master links, same as OEM continuous drive chains, and, vintage bike cam chains having manual tensioners are grossly mistreated (modern cam chains are mostly tensioned automatically) by their not being tensioned properly. Most powersports manufacturers switched from roller type cam chains to link-plate type chains during the late 1970s to early 1980s in response to increased engine sound level requirements. It has nothing to do with strength. Link-plate chains are also known variously as quiet chains, gear chains and Hy-Vo chains. "Hy-Vo" is actually a licensed trade name so is not correct (and certainly not legal) nomenclature. This is the same chain U.S. car makers started using for cam driving purposes in the 1940s. The car guys have always called them "timing chains.". Same chain in both types of vehicles, but with one big difference, and that is application, i.e. how it is actually used. Whereas powersports vehicle engines torture their cam chains with slippers and guides and tensioners, bending and curving them into unnatural shapes in order to fit into compact powersports engine designs, OHV V8 car engines have no timing chain tensioners at all, relying instead on centrifugal force to keep the chain in a constant state of tension resulting in reasonable camshaft timing efficiency. Very different systems, with predictably different results. The fact is, powersports "squeezed" link-plate chains last less than half as long as their automotive free-running counterparts, becoming pretty much used up by 30,000 miles. Chains. Simple yet demanding of informed care. Don't take them for granted.

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