I’ve been running a full SRAM Red setup since August 2022, with a 48/35 chainring and 10-33 cassette. I’ve used Silca Synergetic lube the entire time and have kept the chain very clean. The setup has ~2,000 miles on the road and ~2,500 miles on a Kickr (with a Force 10-33 cassette). While on the road I mostly use the 48T chainring, with the 35T basically only being used when climbing steep hills in the two largest gears in the back. On the trainer I only use the 48T chainring.
A couple weeks ago I broke the chain during a sprint. Other than breaking… the chain looked to be in good condition, and didn’t show signs of needing replacement. I even had a shop near me take a look and they measured the chain to be within stretching tolerance. They were very surprised to hear how many miles were on the chain.
Now that a new chain is installed I’m getting a loud grinding sound when using the 35T chainring under heavy load. On a stand there’s no perceivable sound and it doesn’t look like the derailleur is coming into contact, etc. Everything sounds perfect on the 48T.
The first thought is I went way too many miles on the previous chain and the chainring or cassette are now too worn, however they both look fine from a visual perspective and I’ve spent probably 90% of my riding in the 48T chainring so it doesn’t seem to make sense that it is quiet but the 35T is grinding/damaged/etc.
Thoughts on anything I should check? It seems like an expensive game to start replacing the front chainring or cassette.