i have looked at this fellows auctions and have been tempted to purchase some to see how well they are made.  the shafts will most likely spine in the 70-90# range, but that shouldn't be a problem with bows over 55#.    i often shoot 90# shafts out of my 55-65# bows with no problem.  anytime you can get a straightened bamboo shaft for less than $2, it's a good deal.  let us know how they shoot.