That is a pretty skinny string.You may have to double serve it.I don't think even a .030 serving will give you the fit you need.I know when I was making a lot of skinny strings for my bows a 8 strand D97,10 strand 8125,12 strand 8190 and 6 strand 450+ were all fairly close to the same diameter.I would double serve them.First I would serve with a .017 serving and then serve with a .021 just enough for my fingers.If you do double serve use the larger diameter serving over the smaller diameter serving.Lately I like to make my strings large enough to just do one serving.I have layed extra strands of the string under my serving to make it larger.But it made the serving lumpy and not as round as I like.You may want to bump up the strand count to 12 and maybe you can use a .024 or .030 serving.Its been awhile since I've played with 8125,good string.I have been using more BCY-X and Ultra Cam lately.Hope this helps some?