I mounted up a set of 33c Supple Vitesse SL tires on Pacenti CL25 rims to try them out on some local trails.
While they're not the most aggressive tires for offroad riding, the grippy Japanese rubber compound and ultralight casing make them extremely fast rolling on hardpack and slick rock surfaces.
33mm is a bit narrower that what I normally ride offroad, but for a bike that stays primarily on the road its a good size.
The Supple Vitesse has the advantage of a recessed file tread pattern, which doesn't pick small peices of rock and other debris like many retro tread patterns. The ribbed sections make the rubber softer and allow it more purchase on uneven surfaces, but due to the support provided by the solid areas they don't add much drag when in contact with smooth roads.
We've found that most tires perform better when paired with a rim that opens the casing up a bit. These Pacenti's are just about perfect for this tire.
In case you were wondering, this bike is an early prototype of the Rawland Ravn, which is designed around 26" or 650b wheels. Luckily, since it has disc brakes it's possible to experiment with these 700c wheels as well. The front rack is a Soma Champs Élysées stainless steel mini rack, which mounts to the Nitto standard hourglass eyelets on the front of the fork blades.