I once checked on Comte de Chambord and Louis Odier roses and found Niels' post on pruning - you'll get all the info. on pruning. He is Cup_shaped_roses from Denmark, a very experienced rosarian with hundreds of roses. He explains things well in detail and helped me a lot on winterizing roses.

I was forced to prune my RdO 2 years ago when the arbor it was on blew down in a storm. For climbers, I don't cut back the length of canes, I take out canes. I would take it down to 3-4 main canes and the remove any extra long secondary canes off of those main canes. The rose will respond with a lot of new growth. For basals, I think what I've noticed works best is direct sunlight on the base. I get most of my new basals in the spring because the roses are bare and the sun hits the base (I have full southern exposure in the front and in the winter, it can be very strong).

Paul Zimmerman roses has a good video on climbers, also.

THANK YOU, Buford, on the tip of direct sunlight on the base for basal breaks. This past zone 5a winter, my roses with the most sunlight hitting the base got the most basal breaks. The ones with gloomy northern exposure got none.

I'm illiterate in pruning - my harsh winter and the chipmunks & bunnies do the pruning for me. David Austin catalog has a good section on pruning, and how much to take off for climber: "Climbers: the previous year's flowering shoots should be reduced to 3 or 4 buds, or about 4-6" and the strong, new stems tied in, cutting out older ones as necessary."