I run these tires in 25mm width on a 1982 vintage Peugeot Super Competition that has become, frankly, my Sunday go for coffee bike. In other words, it doesn't get a lot of use. I originally bought them because they were one of only a few quality tires available with a classic look, but I have come to appreciate their smooth ride and durability. When I do take the bike out, I really enjoy the ride. Probably the best tires the bike has ever had. There are better tires available but, If you need tires for a classic steel bike, you can't go far wrong with these.
I love this tire. Solid grip, smooth ride and they roll exceptionally well. I feel they're as fast or faster than the 4000's. Plus, great retro styling. I have about 500 miles on them over some debris strewn Southern California roads and so far, no punctures and little noticeable wear.
I have been running Continental Grand Prix 4000 in 700c28 on our tandem for several years with great results and just put a set of the Grand Prix Classic on my travel bike. I wanted the smoother ride of the 25mm tire and am not disappointed! The ride is smooth and fast. The tires look good with the natural sidewall too!
Used on a set of custom training wheels, these are a comfortable and stylish edition to my race bike. They are sufficiently grippy in the dry and moderately grippy in the wet. I don't trust them to thrash with in all conditions (for that I will switch to my other wheels and GP 4000S tires), but for training they are perfect. The Black Chili compound adds confidence that I can ride on poor terrain and not have to stop often to change a tube. The look is classic (hence the name) and the one size option (25mm) makes for a comfortable ride in rough conditions.
Highly recommended for particular uses.
This tire rolls great and looks great. Glad I went up to 25mm. Very comfortable on rough roads without sacrificing speed. I would recommend these tires for every day training and distance riding.
Whether for training, racing, casual riding, or touring, I have tried many different tires over the years. My standard 'general use' tire for about 8 years now has been Vittoria Diamante Pro. Not only can I train and race on them, their ride quality and durability made them well suited for centuries and casual group rides. I typically ride 10k-12k miles per year of mixed riding and a little racing and the Vittoria give me a solid 5k miles before needing replacement.
I bought the Continental Grand Prix Classics primarily because of vanity. I simply wanted to change the look of my wheelsbikes. I have been wanting to go with that classic, gumwall tire look, but there have not been many suitable choices. Other than the Panasonic Pasela (which I've ridden and like well enough), there just isn't another similar tire currently on the market I would trust as my all-rounder. Continental Grand Prix has a great reputation and I have ridden them before. I went away from them for vanity reasons... I didn't like their particular color for the scheme of my bikes. Now that I've changed my mind about the color scheme, the Grand Prix Classics are a perfect fit, both in looks and ride quality.
The 25mm size makes for a plush ride, but still has a nice road feel. There is a difference between 'feeling the road' and 'having a feeling for the road', if you know what I mean. I felt the road through my Vittorias and most other tires I've used, which is what I expect of a more race oriented tire. These Grand Prix Classics are not race specific tires, but still make me feel well connected to the road without feeling every inch I'm passing over. I do not feel like I'm going to wash out of a corner, as I have with other 'training' tires or other 25mm tires. I'm waiting more time and miles before I can judge the overall reliability and durability. That is the only thing keeping me from granting a 5-star rating at this time. However, if they are like all other Continental products, I should get at least 4-5k miles out of these.