Weakness + cramp sounds more like nutrition problems than bike setup (but could be anything really). A lot of people get cramp when they start to become dehydrated.
How much did you eat and drink during your ride?
I'd guess 35 miles would be over 3 hours? For that sort of time in the saddle, I would probably eat at least 3-4 cereal bars and drink 750+ml water.
I did wonder this.
I probably drank 2l+ out of my camelbak, plus more at the feed stations. It was water with those High5 tablet things in. Plus things like flapjack, peanuts etc and a couple of energy gels along the way.