They must have been pretty tough to be able to pull 166 lbs while on horse back.
Can't even imagine. Especially after shooting about 16 arrows through my 74# longbow.
A lot of the bows of the past though were very heavy bows. Most old English longbows (back into the 1200's) pulled well over 100 pounds.
BTW, Did you know "giving the bird" originated though archery related events?