Riser length

[arachnid]

Hi guys.
When making a 60-62" longbow (Kenny's design) I use an 18" long riser. I'm wondering if a shorter riser, 16" or even 14" long riser (with a 2-4" longer power lam) would make a smoother drawing bow due to longer working limb.

Am I missing something? Is there something I'm not taking into consideration?

[kennym]

It might and will decrease draw weight slightly.  Is the other bow harsh? My testing shows 2.5# per inch out to 29.5 ...

[arachnid]

I don't feel it stack but I'd like to have  a smoother draw. I don't expect it to feel like a recurve, just a bit smoother on the last inches. I don't mind experimenting. I just want to know if I'm missing something.

Have you tried other riser lengths Kenny?

[stickmonkey]

Did you shoot a lot of recurves before shooting Kenny’s hybrid? I ask only because the hybrid does have a different feel to it’s cycle but as Kenny said 2.5 is considered smooth. ( between 2-3lbs per inch )

[arachnid]

Shot a recurve for a bit. I like the hybrid more, being more forgiving and looks damn cool!
I'm wondering how a shorter riser will effect the bow. I want to know what to expect  before trying one...

And while we are at it, will it make a difference  if I use a forward riser design  or a classic?

[kennym]

I think I tried a 16" riser but that was at least 10 years ago when I was doing R&D on the design. If I recall correctly, the 18" gives better performance, but never tried a longer one because of use of power lams does the same thing. So I guess if you shorten the riser and use a power lam, you will have about the same bow with less sight window.


As far as making it a forward handle, no idea...  Be sure to let us know what you find tho!

[stickmonkey]

The forward handle or belly mount  comes into its own imo when looking for a stability and pointability at draw with an aggressive limb profile. That statement is purely subjective.

You can look up the Walk the Talk subsection on the old POA forum and see that performance above 195 fps @10gpp with 16” risers. They all share a similar optimized limb profile and that is the key, having an optimized profile to the risers design.

[Crooked Stic]

I dont see how you could get much smoother than the >003 taper. Less draw weight will be smoother. I think the longer working limb may feel smoother but the performance will suffer if you leave the limb the same (tradeoffs).

[Bvas]

Dor,
Did you use a tip wedge on your previous builds?
If so, you might consider shortening or eliminating the tip wedge instead of shortening the riser.
My first form was a kennym roughly scaled down for a 56” bow. I ended up building a 60” for my son off the same form with no wedges and it was very smooth.

[arachnid]

Brad
I did use an 8" tip wedge.
I think I'll try your suggestion  and build this one without a wedge and see what happens.

[Shredd]

The forward handle or belly mount  comes into its own imo when looking for a stability and pointability at draw with an aggressive limb profile. That statement is purely subjective.

You can look up the Walk the Talk subsection on the old POA forum and see that performance above 195 fps @10gpp with 16” risers. They all share a similar optimized limb profile and that is the key, having an optimized profile to the risers design.

   Can you post a link of the thread you are talking about??  Thanks....

[Bvas]

Brad
I did use an 8" tip wedge.
I think I'll try your suggestion  and build this one without a wedge and see what happens.

If you were using 8" wedge, I would probably just drop back to a thinner 5-6" wedge.  That will still gain you 2-3" of working limb.  You might start to see stack too early if you eliminate it completely, especially if building the shorter 60" bow. 

I don't know if Kenny has built one off his form without wedges?  As I said, my 60" was not quite the same as Kenny's.

[Shredd]

Thanks...

[Roy from Pa]

Shane, sent ya a pm..

[arachnid]

Brad
I did use an 8" tip wedge.
I think I'll try your suggestion  and build this one without a wedge and see what happens.

If you were using 8" wedge, I would probably just drop back to a thinner 5-6" wedge.  That will still gain you 2-3" of working limb.  You might start to see stack too early if you eliminate it completely, especially if building the shorter 60" bow. 

I don't know if Kenny has built one off his form without wedges?  As I said, my 60" was not quite the same as Kenny's.

I don't understand- why will the bow stack if I don't use a tip wedge?

[Bvas]

Once the string reaches 90degrees to the limbs it will start to stack.  Tip wedges help extend the draw length at which this happens. Tips that flex will reach 90 degrees sooner.
If you have a shorter draw length, this probably won’t matter.

[Crooked Stic]

My thoughts on tip wedges are the limb loads quicker on the low end and gives a better string angle at full draw. Too many tapers will cause early stacking. the better string angle eliminates finger pinch on longer draws.

[onemississipp]

A shorter riser will make for an increase in the working limb length, of course.

It will also reduce mass in the riser, of course, which will result in more “hand shock” vibration in the riser area. You could combat that with a heavier wood/lam in the riser area.

It’s not uncommon to see HH bows with risers less than 15”.




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