Getting a bike chain back on after it has come off can be frustrating, especially if you’re on a ride. While it might seem straightforward, there are crucial things to understand to avoid damaging your chain or, worse, causing a dangerous failure while riding. This guide will walk you through the essentials of reattaching your bike chain and highlight a common mistake that could lead to serious problems.
Understanding Bike Chain Pins: Why Reusing Isn’t Always Smart
In the past, bike chains were often designed with reusable pins. However, modern bike chains, especially those from manufacturers like Shimano and SRAM, often utilize pins that are not meant to be reused. This shift is due to changes in chain design and the demands of modern cycling.
One key reason is the way many modern chain pins are manufactured and installed. Many chains now use what are effectively “mushroomed” or “punched” pins. During manufacturing, these pins are inserted with a minimal interference fit for speed and efficiency. Then, the ends of the pins are “punched” or “mushroomed” to create enlarged heads that secure the chain plates tightly. This design ensures a strong connection, particularly important for handling the stress of shifting under load, a common practice among today’s cyclists.
Alt text: A detailed view of a bicycle chain pin with a clearly visible mushroomed head, illustrating the pin’s expanded end for secure chain link connection.
However, this “mushrooming” process has a downside. Once a mushroomed pin is pushed out, even partially, the integrity of this formed head is compromised. Reinstalling such a pin, even if it’s not fully removed, can damage it, leading to a weakened chain link.
The Risk of Reusing Chain Pins
Attempting to reuse these modern chain pins is risky. The author of the original article learned this the hard way with a SRAM chain. Despite SRAM documentation suggesting pin reuse was possible, their experience proved otherwise. The pins, likely mushroomed, failed repeatedly after reinstallation. This highlights a critical point: manufacturer information can sometimes be outdated or even incorrect in practice.
Whether it’s a Shimano chain with reinforced connecting pins or a SRAM chain designed for quick links (often ironically called “slow links” due to their sometimes fiddly nature when dirty), reusing the original pin is generally not recommended.
Best Practices for Reattaching Your Bike Chain
So, how should you put your bike chain back on? Here’s the advice based on best practices and the lessons learned:
- Inspect the Chain and Pin: If your chain has come off, first check for any damage. If the chain broke at a pin, avoid reusing the pin.
- Use a New, Reinforced Pin or a Quick Link: For Shimano chains that use reinforced pins, always use a new, unused reinforced pin for reconnection. For chains compatible with quick links, this is often the easiest and safest solution. Quick links are designed for easy installation and removal without needing to push out a pin.
- Carry Spares: Always carry spare reinforced pins (if applicable to your chain type) and/or quick links in your bike toolkit, along with a chain tool.
- Proper Chain Tool Usage: If using a chain tool to install a new pin, ensure you are using it correctly to avoid bending or damaging the chain plates. Many online tutorials can guide you through this process.
Conclusion: Prioritize Safety and Use New Parts
While the idea of reusing a chain pin might seem economical or convenient in a pinch, with modern bike chains, it’s a gamble not worth taking. The risk of chain failure, potentially at a crucial moment during a ride, leading to injury, far outweighs the minor cost of a new pin or quick link.
To ensure your safety and the longevity of your drivetrain, always opt for a new, manufacturer-recommended connecting pin or a quick link when reattaching your bike chain. Learning from experiences like the one shared in the original article can save you from similar frustrating and potentially dangerous situations on the road or trail. Ride safe!
