Riser length

[critman]

What length riser (fade tip to fade tip) do you guys recommend for a red oak board bow 66-68 inches long? I have seen from 6" to 15". Does it make sense that the longer the riser, within reason, the shorter the limbs and the more the limbs will be stressed? With these board bows excess stress IS NOT GOOD! Believe me, I have broken my share already. Most of the time I go with around 12 inches and have had no problems with the limbs and that length gives me room to cut out the shelf and still have plenty of wood. Thanks for all the help.
critman

[bornofmud]

I think at that length, you're going to want to go with a longer riser to reduce hand shock.  Yes, a longer riser reduces the working part of the limb, but if you're talking about a 68" bow with a 15" riser, I would guess that if it broke it would be either poor wood or a bad job tillering.

Though it seems like you already answered your own question.  If 12" works for you, then keep doing it haha. If you aren't satisfied with the bows you've made of that design, change it.