I always get confused on this one......Will using a lighter point stiffen your arrow spine, or is it the other way round?

Increase weight in the front - weaken the spine (think of it as more to push against so shaft "bends" more)
Decrease weight in front - stiffen the spine

Decrease weight in the rear - weaken the spine
Increase weight in the rear - stiffen the spine

Cool, that's what I thought.....Thanks.

If you increase the weight in the front.....you'll increase FOC but decrease spine?

So why do so many people want a high FOC? Wouldn't that eventually be dangerous?

An arrow will ALWAYS fly heavy end forward. It has to. So if the tail of your arrow weighed more than the tip, it would want to flip over in flight....The closer your FOC is to 0 the stronger that tendancy is and the harder the fletching has to work to keep the arrow stable.

Also, what's the formula for FOC?

The formula is complicated. There is no way I could explain it to you other than saying that it is a consideration of weight and location in relation to the arrow.

When going extremely high on foc,you must choose stiffer spine arrows to compensate for the "dynamic" spine of the arrow after adding the weight to the front.


The foc formula.






3divided by30 = .10 x 100= 10%

Yes, for the deer, that is.

Actually, it could be dangerous to the archer if one were to haphazardly add weight to just any arrow. The formula for success requires careful thought before buying arrows. The arrow spine has to be stiff enough for not only the tip weight you choose, but also for the arrow length, draw weight and draw length. If you do that, then the lower the FOC is, the more potential for danger.

Not technically correct and nitpickers would tear it up but, to keep things simple, that's the effect.

Actually... I disagree. Weight on the back end of the arrow has no effect on spine. Less weight on the rear end increases FOC and so improves stability and gives the effect of stiffening spine. Naturally, adding weight to the rear has the opposite effect.