I converted 2 bikes to 700c. A Bridgestone 400 with side pulls and a Trek 620 with cantilevers. The Bridgestone was easier to do and only needed a medium length brake. The Trek needed a specific adjustable canti on the front but was not too much of a problem. The added clearance and ability to run larger tires on both were well worth the change. I did get both as frames and built them up, so it made sense to me to go with the more available 700c rims and tires.