Advantage of a Tri lam

[Tommy D]

What is the advantage of a tri-lam bow. Do you end up doing most of the tillering on the sides or is it just a question of making the belly wood a lot thicker than the backing and middle layer?

[spinney]

Tommy,

No major performance advantages.
Look real pretty though (Bamboo, purpleheart and lemonwood).

I think substituting heavy tropical wood centre lamination for a lighter wood (ash or sitka spruce) may yeild a performance advantage.

Andrew

[Josh]

The only advantage I can see is besides being aesthetically pleasing, you should be able to glue more bend into the limbs being that 3 thinner pieces bend better than 2 thicker pieces.  JMO   

[medicinewheel]

Tri-lam will store more energy than two-lam at a given reflex.

[knightd]

Tri-lam will store more energy than two-lam at a given reflex.

And be more stable..

[markinengland]

How/why would it store more energy? How would it need to be glued up to get the best out of it?

Dan Perry as in "Perry reflex" feels that a thick belly glued toa thinner backing stores energy better than thinnermaterialsglued together because the belly staveis undermore tension/compression when glued up thus "storing" up more energy. Inmy opinion there is a real possibility of a tri lam storing less energy!

[jeff halfrack]

  Tommyd   dose  have  a  good  question     how  do  most  guys  tiller  a  tri lam?   I'm   curious  as  to  what  a  typical  lay  up  consists?  I  do  my  hbh  with  an 1/8  hickory back and  my  stave    goes  from  5/8  to  3/8  and  I  scrape  to  tiller  and  of  course  I  taper  sides  just  wondering?  thanks  for  any  input  JEFFW

[Lombard]

I am curious about this, as Pat O'Sullivan had some beautiful bamboo back & belly bows, at the selfbow workshop that he and Ryan held last year. Still waiting for the composite workshop   Now that I have some bamboo, (thanks to Hillbilly61), I would like to try one.

[Justin Snyder]

You can decrease the overall mass by having a lighter weight core which give some performance improvement. You can glue a lot of reflex into the core and belly then pull some of the reflex out when gluing the backing on. This puts the belly under compression when the backing is relaxed.

Mark, I think if you asked Dan for clarification you would find that there are different parameters that effect the stress. If you glued the two pieces flat then glued them as a single piece to the backing it would store the same energy. If you glued it all to the form at once allowing the belly and core to slip they would definitely store less energy. If you glue them like mentioned above, they would store more.

[Gordon]

A trilam is easier to glue into reflex because the core is thinner.