There’s no such thing as a maintenance-free chain. At least, not one that will last.
That contradicts what BMW declared last year when it introduced the M Endurance, which was developed in collaboration with Regina Chain and was said to require zero lubrication and adjustment while offering a service life equivalent to a properly maintained X-ring chain (read: 25,000 miles or thereabouts). As hard as that was to believe, BMW insisted that an ultra-hard and inherently slick carbon coating called ta-C applied to the chain’s bushings and rollers gave the links superhero strength.
To quote from BMW's news release when the chain was introduced: "Like previous X-ring chains, the M Endurance chain has a resident permanent lubricant filling between the rollers and pins, enclosed by X-rings. What is completely new, however, is that the previously necessary additional lubricant addition for the rollers and thus the familiar 'chain lubrication' is no longer necessary, nor is any re-tensioning required from time to time due to the usual wear."
Never lube or adjust a chain again? Sounds great! But does it keep its promises?
Put your miles where your mouth is
In reality, the M Endurance chain is good for about 12,000 miles. At least that’s what my friend “Long Haul Paul” Pelland got out of it this summer on his Yamaha Ténéré 700. Paul regularly logs 1,000-mile days in pursuit of his goal to ride one million miles to raise awareness and money for multiple sclerosis. Nine years in, he has over 500,000 miles behind him, all on bikes with shaft or belt drive that he could more or less ignore.
“I’m not good about maintenance or checking things every day,” says Paul. “I just want to ride and then fall into bed.” Understandable, given the marathon nature of his adventures. Needless to say, Paul was enticed by the idea of a set-it-and-forget-it chain, even if it cost $360. So he slapped on a fresh set of OEM sprockets, set the M Endurance chain’s slack as per the Yamaha’s manual, and then did what Paul does. He rode.
A few weeks later, Paul sent a text and a picture of his bike outside the Barber Museum in Birmingham, AL: “About 5,500 miles in, 3-4 hours of rain, some salty New England brine, already stretched about 5 mm. This is going to be interesting.”
His next update was at 10,000 miles. “No lube, no adjustments, no cleaning since installed. Slack is about 9 mm over factory spec.” The accompanying photo showed a grimy chain drooping slightly between the sprockets.
Finally, an exasperated video text: “Here we are, 12,000 miles in and the chain is too slack for safety. I just rode from Lexington, KY, to New Hampshire, and had my rosary beads out for the last 5-6 hours!”
If you thought the M Endurance chain was the answer to your chain-maintenance prayers, sorry kids. We’re not there yet.
With the victim stretched out on the workbench, I could push and pull the length like an accordion and see play at nearly all the pivots. Some links had the telltale “red dust of death” that indicates failing sealing rings. No wonder Paul had his rosary beads out.
When I pressed the links apart, barely any of the factory grease was present and there was visible wear to all the pins. About 10 percent of the pivots had severe erosion due to damaged sealing rings and a total loss of lubrication. Interestingly, the inner diameter of the ta-C coated bushings showed minimal wear, even on the dry pivots. The sprocket teeth looked great, too, presumably due to the graphite-like lubricating properties of the ta-C treatment.
Clearly the ta-C coating is a boon, it’s just not applied to all the necessary parts, namely, the pins. And the ta-C coating doesn’t do anything to benefit the sealing rings, which are still susceptible to friction-induced wear and decomposition due to UV and ozone exposure, especially if they’re left dirty and unlubricated.
The O/Xwhathaveyou-rings are often the, ahem, weak link in any sealed chain, so I’m very curious to know who thought they would last if allowed to run dry and gritty. Lose the seal and you lose the grease, at which point no high-tech coating is going to avert wear. Keeping the seals happy is critical to chain longevity.
You know what a chain really needs to last? A little maintenance. And BMW agrees.
Walk it back, buddy!
“The claim is now going to be ‘low-maintenance chain’ and not ‘maintenance-free chain,’ since depending on the riding elements (dirt, salt exposure, etc.) you experience, it could cause stretch or wear to the non-DLC-coated elements on the chain which would then require cleaning/relubrication as well as slack adjustments.”
That’s the feedback I got from BMW’s Aftersales Marketing Specialist after I presented the results of Paul’s test. A far cry from the set-it-and-forget it promise that BMW originally made!
I appreciate BMW and Regina’s attempt here. Less maintenance means more time for riding, and reducing the amount of harsh chemicals that get sprayed and slung around will help our hurting environment. But for this no-maintenance thing to work there needs to be a ta-C coating on the pins, as well as a leap forward in elastomer technology that yields sealing rings capable of surviving 25,000 miles without attention.
Meanwhile, Paul slapped a new set of sprockets and a cheap Bikemaster O-ring chain on the Ténéré and kept riding, albeit with a dousing of aerosol lube every 1,500 to 2,000 miles (which is to say every day or two). He’s got 12,000 miles on the chain and says it’s still going strong.
Amazing what a little maintenance will do, eh?