I might be misinterpretting what you mean, but the Onza doesn't have a yoke system, but even with yoke cables the limb would still get twisted as the bow is drawn. With any kind of fixed cable rod/slide there's no getting around it. That's one of the reasons Martin came out with the TRG a couple years ago and Bowtech now has their Flex Guard. The idea is for the cables to move closer to the bow's center as the bow is drawn which reduces the side load on the limbs.
Martin used to have an X system on the Fury, Nitrous, and Furious cam which alleviated any and all cam lean (limb twist) that used 4 cables and the string. The arrow was shot between the cables. It was never all that popular with the hunting crowd because most couldn't adjust their pea brains to using it. Most comments I always read made statements about loading a broadhead arrow between the cables and possibly cutting one or more. If some had tried it they'd have learned that you load the arrow from the front and back the nock between the cables and onto the string (a couple inches). It was arguably the best and most efficient cam system (especially the Nitrous) ever engineered. Completely eliminated the cable rod/slide.
Anyway, I rant too much. Hope they figure out your bow. I'm sure you'll keep us posted.
Yes I know the onza doesn't have a yoke system I was talking in general, but those are some interesting facts sounds like Martin could benefit greatly from experimenting with a flex type cable containment system. Also I understand why the quad limbs should help reduce the amount of limb problems.
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