This is what you might expect to hear if a link in your chain is not articulating correctly around the pins.
Video Credit: Neil Catling‎
Root Cause
There are two causes for this sound, depending on the type of closure you use for your chain.
- A quick link / master link was not completely closed when it was installed.
- A pin was installed, but has been pushed too far into the link, causing it to bind.
Steps To Resolve
Quick Link
- Remove the quick link / master link completely, and examine the link. Make sure that the edge that aligns with the pin groove has not been deformed by improper application of force. If the edge has been deformed, throw away the link.
- Reseat the link, and ensure that the edge and the pin groove are aligned. This should be an easy fit. If you are applying force, then the link is probably not useful.
- Using your closing pliers, ensure that the links has fully closed. You should be able to hear it click shut. Make sure you apply pressure to the links on either side of your quick link so that both sides are completely closed.
Shimano Master Links Are Not Reusable
If your quick link is from Shimano, please bear in mind that these links are not reusable. If you try to force the link into place, it may work temporarily, but you are risking a catastrophic failure at some point in the future. Tacx Faqx recommends either KMC quick links, or ABN quick links, both of which are reusable up to six times. Also, make sure you keep track, and always inspect your quick links before installing them.
Pin Link
- Locate the pin which is causing the trouble. It should be the pin you most recently installed, and you can typically identify it because it will be flat on one side without an indent.
- Using your chain breaker tool, position the push rod against the problem pin, and push it very gently outward, approximately .25mm at a time, and test the articulation.
- When the pin articulates freely, you’re done.
Additional Information
Congratulations!
Your Neo is working normally.
I used this stuck link clip to troubleshoot a similar noise with my Cannondale Synapse 105 disk mounted to my Neo II.
The snapping type noise got so it was consistently reproducible on the RH crank just past TDC when pushing the big ring.
I replaced the BB30 bearings but also found that two adjacent bolts (of the five) mounting the front rings weren’t tight.
After reassembly and torque, found I needed to adjust front derailleur as front big ring now sets more inward and much quieter on the Neo when pushing the front big ring.