Ok I have been study these bows a bit, though not know everything for sure~
who does??
Anyways, Simpler version of horn bow would be one of wood belly, common among infantry since not all can have a good horn bow.
Bamboo core, sinew back and wood belly. Though not sure what belly wood used, mulberry is good idea. The siyahs would be commonly of elm wood and also the grip.I do not think bamboo backing idea ever was used by the mainland. In Japan, it was used because they find a sinew backing will not work.
On the normal bow, you want the bamboo core to face down, on strength test bow it faces up.
Siyah can be single piece or two pieces splice together. Both are common.
The handle can be spliced to the core, but I think this practice would be more common with the wood core. For bamboo, simply glueing it to the core's back is done. It must be made so it sets the handle back.
170 cm seems about an average for length.
Limb width of 3.8 cm or so, thickness would be slightly thinner than horn bow, which has average of 1.5 cm.
The core is about 122 cm long and 6 mm thick.
Siyah measured from the knee is about 30-35 cm long, splice is maybe 10 cm long. Angle of siyah is around 60 degrees.
It is around 3 cm thick for its length and 2 cm wide.
The handle is bulbous, and about 8 inches. (the handle block)
Also, make sure to have string bridge!
