I am having problems with replacing brake cables on rear wheel. The bicycle has mechanical disks. I removed old cable successfully and I've put the new one in. The thing is that I feel like it's not tight enough, but I cannot tighten it more. When I try using the brake, it doesn't brake at all.
I didn't cut the cable yet because first I'd like to get it working properly. Do you have any clues on what's wrong? I don't think that I need to adjust the brake, as I am only changing the cable.