What is the best riser length?

[Noah70]

I was bored and decided to make a laminated wood bow, no glass.  I ended up with 5 laminations as follows.  Width is 1 3/8", length is 68".  Back is hickory, tapered .002 with 16" center parallel. Core is 2 laminations of bamboo, both tapered at .002 from center. Belly is 1 lamination of Yew tapered .002 from center, and 1 (outer) lamination of Yew parallel.  Total stack is .580 center and .486 at 20" from center.  The plan was to straight taper to 1/2" from the fades. I glued it up on a shallow Deflex/Reflex form.
My original thought was to make the riser 16" to the tip of the fades, and glued up a couple of scrap pieces, but am now second guessing myself on the length.  Is there an optimal limb length for a build like this?  I like a bit of a contoured grip and some sight window, but am open to opinions and some insight.

[Mad Max]

Your riser looks short in the picture.
Your lam stack could pop off the riser, I would use a power lam (I call it) to keep the bend away from the end of the riser---1/8" thick and taper 2" on each end to 0, So 4" longer than your riser.
You could put it in the stack above the belly lam, I think it would work better there.

You should be fine with that combo. for a 68" bow

Just look at the power lam in this drawing

[Noah70]

Thanks very much for that!  I was considering an accent colour lam between the riser and bow, so will extend it a bit further. I was also going to apply an accent to the riser ends as a cap to cover the end grain of the fades, so will extend that down the belly as well to assist in distributing the load.  Much appreciated!

[Longcruise]

Thats a lot of taper especially coming of parallel at, is it 10" from center?  How wide at the nocks?  Maybe a tip wedge?

I'm a glass guy so keep that in mind regarding my comments.   Maybe Roy will check in.  He will have some thoughts for sure.

[Roy from Pa]

I make my risers 12 inches long on my BBO bows.

[Noah70]

Thanks, I've always worked with glass too, just thought I'd give this a try. Made some self bows over the years but this is a new ballgame. I might have gone a bit overboard on the tapers, but haven't cut the shape to the nocks yet. Just glued on the riser this morning, but it's at 14" to the tips, so maybe I'll cut it back when it's cured. The limbs are 575 at the fade, tapering to 355 at the tips, over 27" limb.  The parallel belly lam is thick enough that I can pull some off near the riser if the tips are too loaded? If nothing else it's great experience! And firewood, worst case
Thanks!

[Roy from Pa]

14 inches will be fine on a 68 inch bow.