Condensed Answer: Officially, Shimano’s quick links are designed for single use only. Therefore, the safest approach is to never reuse a quick link.
That said, there’s a lot of anecdotal evidence from people who have reused Shimano quick links without experiencing issues. If you want to preserve the warranty of your equipment, however, it’s best to avoid this practice.
What are the downsides of reusing a Shimano Quick Link?
- Loss of strength
The main issue with reusing quick links is the loss of strength in that link. Each opening and closing of the chain via the quick link creates friction between the link’s pins and plates. The result is a microscopic loss of material. The losses add overtime and hurt the integrity of the link.
In the worst-case scenario, the chain will break unexpectedly. The aftermath ranges from mild annoyance to a bad accident with an unpredictable ending.
For that reason, even officially reusable quick links are not meant to be reused more than 2-3 times throughout the lifespan of the chain.
- Loss of warranty
If you don’t use a manufacturer’s product as intended, the warranty is automatically lost.
Anecdotal Evidence
We’ve already covered the standard and official answer to this question. In the name of accuracy, however, it’s also necessary to mention that many people have reused Shimano quick links without reporting issues. Some people do it to save money while others simply do not know better. There are even experienced mechanics who consider the frequent replacement of a quick link unnecessary.
FAQ: Should I change the quick link when replacing the chain?
If the chain has seen significant wear, it’s recommended to retire the quick link along with it. As the chain rotates around the chainring and cogs, the pins holding the plates together experience wear. Their decreased diameter is considered a compromise, and it’s therefore recommended to get a new link.
That said, if the chain link is reusable and the chain is fairly new, it’s not as risky to reuse it. I’ve done so myself. The link on my current chain is a reusable 8-speed from KMC.
FAQ: Is it true that back-pedaling increases the risk of a quick link snapping?
Technically, yes. When you’re pedaling forward, the tension stretches the chain and essentially reinforces the quick link connection. When you pedal backward, the quick link plates are pushed towards the rear wheel or in other words in the direction of removal. If the quick link is worn it may come undone. However, if the quick link is in good condition, this is highly unlikely to happen.
