I have a 1978 Trek TX900. It's ideal except for two issues. The bike will take a 700x28 tire, but a 700x32 will not fit. The stand-over height is tight (I can stand-over the bike, but have almost zero safety factor).
I'll need to install a wider tire on this bike for some gravel road events in 2013. I have a modern Cyclocross bike with 700x32, but one of the events I'm considering requires a vintage bike. I like the 700x32 size for gravel roads and for my everyday cycling.
A 650b conversion will allow me to fit a 32mm wide tire like the Grand Bois Cypress 650B, see: http://www.compasscycle.com/tires_gb_650_32.html .
However, I'm concerned that the smaller diameter tire will change the trail of the fork and create a less stable ride? The fork rake is 4.5cm according to the Trek Catalog. What rake would be ideal to preserve the Trail?