Jim’s Tech Talk
By Jim Langley
Before getting to the technical Q & A, I goofed last week and didn’t show you Bruce Ross’s favorite bike bling saddle. It’s this tri-color masterpiece by Busyman Bicycles. Nice, huh?
Now, to get on with the show, an important question (read to the end to find out why it’s important) came in from retired RoadBikeRider founder and Team RAAM record holder, Ed Pavelka. Since he handed over the RBR reins almost exactly eight years ago, Ed, now 72, moved south and still rides lots, averaging 12,000 miles a year. “It’s more fun during Florida’s winters than in its long hot summers,” he notes.
Ed’s Important Question
Ed wrote, “I have a question that you may have already covered for RBR or perhaps somewhere on your website. It’s about SRAM PowerLinks.”
Editor’s note – SRAM PowerLinks are special links provided with new chains. Sometimes called “quick,” “connecting,” or “master links,” they are used during chain installation to join the ends of the chain without tools. SRAM and other chain companies make these special links. You can see how the SRAM links work in the photo. For the model of chain Ed is asking about, SRAM calls the link the PowerLock Chain Connector 11-Speed.
Ed continued, “For more than a decade my main bikes were 9-speed and I ran SRAM PC-971 chains. I loved the PowerLink feature and used it to easily remove chains for cleaning and lubing. I never saw a warning against using a PowerLink more than once and I never experienced a chain problem from a reused link.
“Now I’ve upgraded my steel and titanium Independent Fabrication Club Racers to SRAM eTap and 11-speed drivetrains with Red22 chains. According to SRAM, the PowerLock can be used just once — for initial installation. That is, if the chain is removed for any reason a new PowerLock must be used to rejoin it. Find the PowerLock on Amazon.
“Why can’t a PowerLock be reused? I lube with Rock & Roll Extreme so I never need to remove a Red chain for cleaning. But I do remove the chain sized for my 11-26 Florida cassette when I put on the 11-36 for annual cycling vacations in the hills of Pennsylvania and upstate New York. Then I’ll remove that longer chain when I return home and put the shorter one for the 11-26 back on.
“This means I could reuse a given PowerLock several times during the life of the chain. If I do this instead of installing a new PowerLock each time, what’s the problem? After all, the PowerLock is being pulled tight by the direction of chain travel. How could it fail?
“I did snoop around online and found a pretty even divide — some people say the 11-speed PowerLock is reusable, no problem; others say it’s strictly for one-time use. Which is correct?”
Great question, Ed! I wasn’t 100% sure myself, because I have reused about every connecting link going. So I decided to go straight to SRAM for an answer. I reached out to Road Marketing Technical Rep, Nate Newton through SRAM’s online link
What Nate wrote back surprised me because like Ed, I assumed that a connecting link will hold the chain together no matter what. It turns out that’s completely wrong. Read Nate’s explanation — I put the important part in bold:
“Our 10- and 11-speed PowerLocks are one-time use only, because as they are removed, there’s enough deformation at the interface where the pin clicks into the plate that a second install will not be as secure. The potential failure mode is the PowerLock opening on its own when the chain goes slack. You can hear and feel that on initial install, the PowerLock installs with a loud click, and requires a tool to re-open. But on subsequent installations, it installs silently and with no effort, and can be re-opened by hand.”
I wanted to also get an opinion from an impartial tech expert, so I sent the same question to one of my most trusted industry friends — someone with extensive current experience testing all brands and models of connecting links. He prefers to remain anonymous.
What my tech guru says is almost the same as what SRAM said, and he shared some failure examples:
“Jim, I STRONGLY urge you not to recommend your readers reuse those links. Some may weigh in saying they have reused them without issue but it truly isn’t a question of IF they fail but WHEN, once you go off schedule and choose to ignore the manufacturer’s recommendation.
“The failures I have seen in testing are in two places. First, at the pin / outer plate junction. On one I had fail on my bike, I literally saw the pin fall out of the outer plate on the side where it was (previously) permanently fixed at the factory.
“With the master links like SRAM’s you also ‘feel’ the link positively snap into position. As the link is reused the positive engagement disappears as the engagement hole becomes enlarged and elongated.
“This creates a second point of potential failure especially if a rider hits a bump or has a sticky freehub that detentions the chain (think forces that replicate pedaling backwards) allowing the pin in this now oversized hole to partially or fully fall out while riding.
“If that happens, the unsuspecting rider re-tensions the chain only to experience a very sudden failure. And, as I’m sure you’ve seen or perhaps had happen to you, this usually results in a bad crash. So, again, please advise your readers for their own safety to not reuse the links.”
I’d like to thank Nate at SRAM and my anonymous expert for clearing up this uncertainty.
A Link You Can Reuse
As Ed mentioned, having a link you can open and close more than once comes in very handy for cleaning and changing chains. It’s also smart to carry such a link in your repair kit for easy repairs should you break a chain on the road (some roadies call these links “chain patches” — always liked that name).
While we now know that the SRAM PowerLock is not designed for reuse, there is a popular connecting link that is — Wipperman’s Connex link. It’s said to work on any brand of chain. Learn more: https://www.connexchain.com/en/connex-connector-bike-chain.html. They are available at bicycle shops and Amazon.
Ride total: 9,122
Jim Langley is RBR’s Technical Editor. He has been a pro mechanic and cycling writer for more than 40 years. He’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Check out his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter. Jim’s streak of consecutive cycling days has reached more than 8,000. Click to read Jim’s full bio.