Been riding the 5000s (regular version) for a couple weeks now and have a few hundred miles on them. 23mm in front, 25mm in rear, latex tubes. I'm 145lbs. I've gotten to do a lot of varied riding on them, including a very wet and rainy crit and gravel. IMO they are excellent tires.
I used to be a die hard Veloflex fan. I rode them for many years for the ride quality. I switched over to GP4000s because they wore better and rolled fast. I could tell they weren't as supple as the Veloflex but I was tired of how easily they cut. I was really excited to try the Michelin Power Competitions, but those were a failure for me. They roll fast and feel good but I got bad sidewall cuts that ruined the tires and made them unrepairable. Bad luck I suppose. I also tried some Vittoria Corsa G for a time, because I got a deal on them. They are okay. They are pretty durable for a supple tire, but they don't really ride that great for me. Not sure why. They definitely don't ride as nicely as the Veloflex. In any case, the 5000s are undeniably fast and IMO feel better than the 4000s, and better than any of the other tires I've mentioned above save for the Veloflex. I haven't ridden them for a few years now so can't really do a direct comparison but the 5000s feel close.
First a reminder: With wide rims the norm, conti resized the GP5k to be the width it now appears on ON THE RIM. So your GP5k in 28 is the width of your old GP4K in 25 when it's mounted. Second, there is a bit less tread there- something like .2mm. So obviously the tire is really no lighter than the 4K in the same ACTUAL size. Still, I went ahead and replaced one of my GP4ks in 25 with a 5k in 25. I've ridden it through some pretty bad debris-on-highway-shoulders so far and durability has been great. I'm impressed by anyone getting over 2000 miles out of any tire. I don't try. The 4K would always flatten (wear down) at the top of the tread well before the wear indicator got anywhere near replacement depth and that's when I have problems so I replace early. I thought I'd give up some cornering prowess with the smaller size but didn't notice that either. Race last weekend revealed this to be a fast predictable tire, just like the 4K. No complaints, I'm buying more.
I'm only giving this tire 4 stars because they were a bear to mount on my daughter's Mavic Cosmic wheels. Just for reference we bought the 25s. I'm not sure if the larger 28s would be any easier but I kind of doubt it. She's good at changing flats (especially for a 14 year old) on the road but if she does gets one either I'll have to come change it or she'll need help from someone fairly strong.
After struggling for a bit and almost breaking my tire spoon I ended up attempting to prestretch them by pulling as hard a I could with my feet and hands for about 10 minutes. Only then could I mount them with a tire spoon. Usually I can get other non-tubeless tires mounted by hand.
She's got about 200 miles on them so far and enjoys the ride quality and grip.
With any luck these will last the spring and summer CRIT season.
A GP5000s 28mm is a bit smaller in height and width than a 25mm GP4000s, as measured installed on a Shimano RS500 alloy wheelset. I assume the 28mm would measure wider, on a wider rim. Old 25mm GP4000s tires just barely cleared my brake bridge, but the new 28mm tires have about 2 more mm of vertical clearance.
New tires get a bit larger after a few days of being installed and under pressure. The GP5000s 25mm tires are even smaller still yet. I use 95 psi in the 25mm GP4000s and 95 psi in the 28mm GP5000s tires, both ride the same near as I can tell.
I had been searching for a tire that would not get punctures when I rode vaguely near some piece of detritus with an edge or a point. I had tried other highly rated tires but with no success. The Continental Grand Prix 4K & now 5K do the trick. I imagine they are heavier than some but I can live with that. They are a bit pricey, but since I have to replace them less often, I'm probably not actually spending more. I certainly get a lot fewer flats which makes riding far more fun. As long as Continental keeps up the quality, I'll keep buying them.
Like many, I used the 4000s II for years and loved them. This newer version has less tread thickness and costs more. I bought them based on my experience with the previous model, but cannot recommend them due to changes in manufacturing and the price. There are more 700C sizes available in this model and the graphics are smaller and more appealing to me. It is still a good tire but Continental has not advanced the model technologically as much as the introduction of Black Chili compound did years ago.
Bought these for a 200mi, 2-day charity grand fondo as an upgrade from an all-condition tire I was training on. I'm 186lb so run these 32mm at 65-68psi. Comfortable yet firm and secure in the turns. Only one flat in the ~800mi I have on them.
