Don,
PABowhntr, From what I have noticed, if you need a long draw length, one of the ways of acquiring it is by finding a bow with a longer BH. (bows with a 31,32,33in or higher draw length are going to have a long BH)
Say for instance if you have two exact bows, but one has a BH of 6 1/2in and the other is 7 1/2in, the longer brace height bow will give you a longer draw length.
As Len stated, this is not a correct statement. On any given bow, brace height is not affected by draw length...with one exception. Lets take a Mathews MQ1 for example....each inch of draw length is determined by a different sized straightline maxcam. As you get longer in draw length the straightline maxcams get bigger. As the cams get bigger the brace height gets slightly larger....but only slightly and only in the case of bows that use different sized cams to achieve the different draw lengths.
Bows that use rotating modules...Browning Cyber, Hoyt Cam.5, etc....and/or replaceable modules....Jennings PWC2, Parker Single cam, Bowtech dual/singles....do not have their brace heights change as you either increase or decrease the draw length within the given draw length range of the cam. In the case of the Cam.5 as you go to shorter draw length range..say from a 28.5-31 to a 27.5 to 30 then the brace height might, again, change slightly, as the cam size gets smaller but not by a significant amount. A 28.5 inch draw length Razortec will have the same 7.25 inch brace height as a 31 inch draw length Razortec provided both draw length range settings are on the same rotating module.
Voz,
Again, I tend to agree with Len. If you have a longer than average draw length then I suggest you stick with bows that are a bit longer in axle to axle length than 28.5 inches. The string angle, alone, with such a setup would be extreme to say the least.