I upped the rubber for the chest plate crossbow.
It now has 68 kg (150 lb) of a draw. Major speed improvement! I am still not at my limit, but this by all means is a heavy draw weight. 6 bands of TB Gold per side, 10 cm (fork) and 6 cm (pouch). That means a total of 60 cm x 36 cm. Or 3,5 full TB Gold sheets per side.
I made my own crossbow string from Dacron. This one has 115 strands! It is as tough as a horsewhip.