others with more experience than I will pipe in , but do be careful not to over turn the tightening bolt. I seem to recall Brooks recommending small amounts, like 1/4 turn. In any case, start with a little turn and see how it feels, its easy to do more later (and/or combined with lacing if need be)
also, I did notice that last summer I had to reposition my B17 a bit more forward so that my bum was a bit further back in the saddle (the saddle adjustment I did that caused this was my error, but only figured it out a bit later after having chafing issues)
also a slight upwards saddle angle helped me too, but you will know what works for you or not.