RE: It is NOT cam lean!
I think it's great that some took the initiative; and, some of you were really on the right track.
When I first made comments about this new cam system, I said that it would take some time to really evaluate its positives and negatives. I still hold to that statement and will continue to analyze this product. A few have made a real issue about 'cam lean' that grew into a furor and quite a controversy in recent weeks. As with many issues on the forums, it was getting emotional and needed some context.
I had done some evaluation of its shooting characteristics/consistency and was impressed. I took one bow apart and did a tolerance check and was again impressed; especially with the axle fit to the limb and bearings. If anyone has the capability, I'd like to hear their input on these matters. After all, I've only been able to take a small sampling of the dozen units I have in stock. I plan to sample more later; but, I like to take samples from different 'lots'.
One thing we have to do is DEFINE cam lean as it is different from limb twist. Just like the definition of timing and synchronization can be confused, so can these terms. We also have to understand when things can be controlled, IF they must be controlled, and HOW they should be controlled. It is best to distinguish between these two for various reasons. First, identifying the causes becomes easier if you're analyzing both. Second, and in this case, it's more fair to the cam design. I'll explain later. *
Cam lean may be what you're seeing because the cam IS leaning; but, what is the cause. I refer to cam lean as a variance in the degree of straightness due to worn bushings and/or bent axles. Limb twist is where the limbs 'bend' due to various influences. In this case the influence would be the cable guard. There are other cases of limb twist which are permanent. This was the case in some older designs and some of the split limb designs that were manufactured inexpensively. In this case and in every case of bows using a cable guard, limb twist WILL be an issue.
During my Dealer Seminar at the ATA Show, I discussed the usage of lasers and how just one method shouldn't be totally trusted. This is apparent moreso now that this issue arose. If you laser or even straight-edge the cams, they will show minuscule lean in the static mode. In the dynamic mode, however, the lean becomes more noticeable. If I use one laser design, it just shows me cam lean. I have to use a second design that will tell me if the limb is twisting. If the two agree, it reads one way. If they do not agree, it reads another way.
I checked my entire stock of BowTech Binary and many other manufacturers, which is substantial. The amount of cam lean in the static condition was better than most. The dynamic condition for the binary system was average to better than average. Even the much more expensive limb designs were not significantly better.
Keep in mind that Gordon Glass builds about 80% of the limbs in the market. What we're really seeing, in not only in the design but the construction, is 'commonplace' with today's technology. And, it doesn't matter whether or not you have a split yoke system, there will still be limb torque/twist when using a cable guard. By adjusting a yoke, you're really just preloading the limb. It then becomes critical as to how much you're 'influencing' the end result. I've seen situations where the cam lean/limb twist was corrected by twisting yokes to the point where the cable(s) MISSED the stop(s). I've done a lot of dual cam bows for some tournament shooters. It's a tenuous job of obtaining that 'balance' of the system for optimal results. Can you get a better shooting bow? Yes, but it would take a top-notch shooter to see the difference. In most cases it would be a "feel good" situation.
What I have found is that the cam lean/limb twist in this design is really not as much as we've been subjected to for a decade - and we shot those well. I also have noticed nowhere near the cable wear as has been experienced with other designs. This might change, but I have my doubts.
*The reason I decided to report my findings at this time was not that cam lean wasn't there; but, that it was being misinterpreted and somewhat blown out of proportion. I must admit that I was negligent in doing the dynamic tests right away. The bows were shooting so well that we didn't see an immediate need. We have tuned these bows easily and shot FTs and FIXED BHs into the same holes at around 300 fps @ 25 yds. We haven't had the opportunity to do long-range tests because of the weather/facilities. If someone else could chime in on their long-range FIXED BH results, I would love to hear about it.
Well, that's all for now. Thank you for your patience.