We recently mounted with my father this Afam sprocket on his bike and the truth is that the change is quite noticeable. The first thing to mention is the quality, it looks sturdy and well finished, and when mounted it fit perfectly on the shaft, no mess or weird adjustments.
We took the 17z because my father wanted to lengthen the development a little, and we got it right. In town it still has good output and response, but on the road it is much more relaxed, without being so revved up, which makes long journeys much more comfortable. In addition, the chain works smoothly, without strange noises or vibrations, everything perfect from the first moment.
Fitting it was very easy, it was ready in half an hour. I've tried other brands, but this one gives me much more confidence because it lasts longer and doesn't wear out so quickly, and it really pays off, because you don't have to change it so often.
In short: very good buy. Good price, good quality and extra comfort when driving. We will definitely repeat with Afam when it's time to change again!