i had them both since they were 4 weeks old that was like last summer so they are around 1 and a half but he has one kid so far and that was with a bigger then that was 4 months ago ... i see the other silkie rooster mate her sometimes but my silver partridge grew up with the hen so i thought it would be better and she wouldn't run but she does and she doesn't she is mostly with him and not with the other rooster .. i have 2 pairs ... so im not sure why he does it but i hope its nothing just not good at mating or never got the hang of itWell, as long as she keeps running away from him when he is trying to mate with her - then yes - he will keep doing it. She is SUPPOSED to stop and squat down so he can mate - NOT run away! Or course - if he is young and hasn't figured out what he is doing yet and his hormones are raging ... that may also be a problem. It will go away when he grows up if that is the case.
With Silkies I have noticed some Silkie boys just aren't sure how to get the girl, and those girls play hard to get! Sometimes I think that is more the problem with fertility than the big fluffy butts. Once they had it figured out the fertility went way up - without any trimming or fussing. Rooster flirts - rears up, hen squats down, roo jumps on and shoots, off he jumps and hen shakes off and goes back to eating, scratching - whatever. No fuss, and fertile eggs.