I noticed on the inside of the crank spider of my GRX 1×12. It looks like the spider arms can accommodate another or different size sprocket. But I’m not really certain and I’m wondering if anyone is familiar with how these threaded holes are used. The bike is a Trek FX 6 sport.
by Defiant-Attention978
1 Comment
That’s for a 2x set up. Smaller ring would go into that slot while a larger, non-1x chainring would replace your current one.
https://preview.redd.it/836ve9pcztxe1.png?width=1280&format=png&auto=webp&s=b3225d0ffc249d42f546c111c91b4d985a7ec775