Forgiveness - does it exist?

[The Meggy]

Is there such a thing as a more "forgiving" bow? Conventional thinking has it that a) longer axle to axle length = more forgiving b) higher brace height = more forgiving. But can a bow setup really somehow "forgive" your errors and steer the arrow back into the gold?

I suppose a "more forgiving" bow is one that gets you better scores in the end, but how useful is this concept really? A lot of the better compound archers use relatively fast bows often with lowish brace heights and quite short axle to axle lengths so presumably for them this is the "most forgiving" setup. But is this true for the average club archer also? Should someone at say 1100 FITA level buy a different bow to someone at 1200 or 1300?

What do you good folks think on this issue? Are there any other factors that affect "forgiveness"?

Cheers The Meggy

[Little Miss Purple]

I think many factors can offer each archer their own forgiveness.. bearing in mind that we are all unique and our technique varies accordingly. One shoe certainly does not fit all!!

[geoffretired]

I remember shooting a bow with an overdraw. I shot it once and took it off.
It certainly enlarged the groups; or so it seemed. I guessed at the time, that the slightest change in my hand position, caused a bit of torque that was magnified by the overdraw, as it was well behind the bow's grip.
I suppose, compared to that, my original set up was more forgiving of my mistakes, but that could also be seen as misuse of terms rather than a true account.
If a bow exaggerated my mistakes, I wouldn't want to use it.
Perhaps a forgiving bow is one that exaggerates the mistakes to a lesser extent than other bows.

[Rik]

I don't like the word. It smacks of choice and your equipment can't choose.

What you do get is that some set ups will maximise your errors and some will minimise them (and there is a continuous range of levels between these two extremes).

A case in point. I was talking to an ex-european champion compounder about his tuning setup one day. He explained how he had previously spent ages tuning for perfect arrow flight, only to find that his groups opened up. "de-tuning" so the arrow flight wasn't as good, led to better groups.
The second setup could be termed more "forgiving" than the first.

If you say a good shot is a good shot, no matter what your setup, and a bad shot will go bad ditto. Then what happens to the range of shots inbetween? The best setup for you will produce the best results from those shots. A bad setup will produce worse results. The equipment doesn't "forgive" bad shots, but you want a setup that doesn't make them any worse than they strictly have to be...

You can't measure "forgiveness". You can measure group size.

[Murray]

For me forgiveness IS group size. The bow setup which provides the best "tune" (whatever that is ) = best groups = most forgiving of my form errors.

I am in no doubt that there are some configurations/bow geometries which are more able to produce tighter groups than others in the hands of a human shooting machine!

[moo-mop]

Originally Posted by Rik

You can measure group size.

I know what you mean but a meaningful measure of group size re equipment set-up usually isn't as possible as many would make out.

I don't know the details for compound but with recurve, you'd have to be better than around 1250 to be able to see a group size variation caused by normal changes in equipment without hundreds and hundred of arrows in prefect conditions. I've (even when I was shooting better) found my random variation masks any variation in group size that might be introduced by a less 'forgiving' equipment set-up. It may be easier with a compound but still I don't trust all I'm told.

Most tuning, therefore, uses a system (eg in recurve bareshafts indicate the arrow is coming out of the bow flying straight and the thought is flying straight means you will group better even if you can't prove it).

[sambow]

I have shot various bows and consistently found that I group tighter and score higher with bows that have a long ATA and slower cams. I also believe that when I accidentally punch the release, the error that results is lower with a longer ATA bow than a shorter ATA bow (that is a subjective belief). Personally I consider these bows to forgive a badly executed shot more than the bows I have shot with shorter ATA and faster cams. Then again it may be the slow, long ATA bows better suit me.

[Jerry Tee]

I have been thinking about this for a while and I have come to the conclusion that the vertical paradox that occurs with a compound bow is for the most part ignored. Logically there must be a state of tune that causes this paradox to to flex the arrow so that the fletched end of the arrow is flexing up at the point where it goes over the arrow rest. Once you accept this it also becomes aparent that a higher bracing height will allow more distance for this to happen.
I think that the optimum tune would cause the arrow to come off the bow string as it is bending so that the nodes are in line to the target. This would cause the minimum distrubance as the node of the arrow moves forwards from the nocking point ( when the arrow is on the string) to its normal free flexing point when the arrow comes off the string.

[phil_r_58]

I think "forgiving" is not the correct term. Certain elements of design and set up, however can cause a bow to become more "critical" to errors and inaccuracy.

Back in the old days of round wheel cams, the optimum position for the axle was 1/2 way between the centre and the edge. This gave 50% breakdown. Moving the axle more to the edge could give more breakdown, we went to around 80% in tests on the wheels we made. But when going over the 1/2 way point, the more the breakdown went over 50%, the bow became more critical, to the point where even archers like Mike Houghton could not get consistency. When you think about it, using a lever* to magnify the movement of the limb, will also magnify any error.

(* The wheel type cam was a circular lever. If you use the radius line from the point of tangency formed by the string to the axle, you have an infinite number of levers in essence.). In cams, the straight line relationship changes, and you have in effect bell cranks. But none the less still forms of levers.

Cams are maybe not so critical as the old co-planar wheels, but the faster you make the bow shoot, the more you also magnify errors still applies IMHO.

An over simplified explanation I accept, but the maths involved in calculating involutes to a circle is pretty conceptual stuff, and not one for short forum entries. It's way beyond me too, but I know a PhD mathematician who can, and explain it to a noddy like me.

[geoffretired]

Phil, I have thought for some time now that the best place for cams is near or on the riser, like Oneidas. Cams lean for three reasons, as far as I can see. Loose fits on axles, loose axles in the limbs, and limbs twisting as the forces build up on one side more than the other.Also, cams on the riser would allow the limbs to return faster as the cams' weight/mass would not be slowing the limb tips. I suppose that would impose other limitations on the bows that I haven't considered. Any thoughts?