when you sparge you should do so with much higher temperatures, say 170 which will denature the enzymes and stop conversion. Your 159 will probably denature the beta amylase in 45mins anyways.
read this (section 4.3.4): http://books.google.com/books?id=zV9...wO8I#PPA104,M1
and actually the whole book is a good read.
btw, nice bike, I'm looking at sucking the orange kool-aid soon, but might go with a husky.