One thing that you will really need is extra balloon tires none of which that I know of exist. Having said that your idea is not realistic. Even if you outfit the bike with superior brakes and beef up the frame at all points of stress. Your traveling at speeds that require tire that have enough volume to absorb uneven road surfaces holes and such if you use a typical balloon tire the largest you can find it will not be enough and you will lose control when moving at speeds over 40-45mph.