There has been a whole lot of buzz going around about these tires since their arrival on the market - they are lightweight, durable, roll fast and stick like glue. All the things you are looking for in a high-end performance tire.
The first thing you will notice with the Ultremo is the lack of rolling resistance and incredible grip. This is due to Schwalbe's Triple Star Compound. It has a harder density rubber in the center for effortless rolling with little to no resistance. This tread is sandwiched on each side with sticky rubber that really hugs the road. The lightness of the tire (189 grams) combined with the lack of rolling resistance and pure grip makes a massive difference and will become apparent from your first pedal stroke. They will actually improve the way your bike handles.
Protection from the elements and debris are taken care of by HD Speed Guard strip under the tread. The strip does an excellent job of preventing flats, but also doesn't impact performance. The strip is pliant and bends and flexes with the tire carcass so it will not impede with the tire contact as it contours to the pavement. Many manufacturers use a Kevlar strip or other stiff materials which tend to make the tire less responsive and decrease grip. The HD Speed does it job buy protecting the tire but not affecting the ride quality. There is some added material to the side walls to reduce sidewall flex for a more protection and secure feel.
The tire designers at Schwalbe claims " the Ultremo is the pinnacle of our ambition" and we can see why, it is one of the finest clinchers available. They are available in 23mm width in a range of colors.
Great tire. I decided to try these after using Continental GP's for a decade, and these are every bit as good in terms of puncture resistance, and the ride quality/handling are better to me.
I have about 1,000 miles on them so far, riding on late fall and early winter roads covered with grit and salt, with no punctures or cuts. I definitely recommend these.
Pros: low rolling resistance, durable, handling
I loved the previous R1 version--for all the reasons quoted here-insanely light, great ride and easy to mount w/o levers. The ZX is a few grams lighter, however I've had two tires get massive chunks taken out of them with the cut going all the way through. On one occasion, it was the FIRST RIDE!
Pros: Light weight, rolling resitance, easy to mount
I installed the black ZX for the 2011 Death Ride and no problems. Still have them on and they ride great. Never have any flats on them and wear evenly. I weight 220 and there is about 1000 miles on them. Low resistance and fast. They are easy to removed - no tool. They're seems to be lower profile then the Vittoria CX.
Pros: light weight and low rolling resistance
I grabbed a pair of these last year and at first it took a while to get used to the "road feel." I felt like the tires were barley in contact with the road. The claim about low rolling resistance was pretty true. A gust of wind seemed to move me across the road. I had a couple of flats with only about 250 miles on them. I was concerned that they were going to be a problem, but since I've not had any flats. They are still rolling strong but have developed a couple wear-out points on the sidewalls after a year of pretty consistent use. I'm a heavy rider, 200 lbs, and run them at about 120-125 psi.
Pros: fast, low rolling resistance, decent mileage
Cons: sidewalls seem weak
I liked the specifications and bought four tires from my local pro mechanic. One blew apart and the other developed a bulge. Schwalbe is a foreign manufacturer and the warranty was impossible to use. The US dealer also was no help. Unless there are new test results and they stand behind the product, it is hard to buy. Hard to make the finish line on flats.
We have had zero problems with the ZX tire. In fact, we love them. Had the reviewer bought them from us, we would have replaced the tire with another ZX or tire of their choice(or a refund). No questions asked. - ed
Pros: Light weight
The ZX has more meat than the R! and rolls good. I put it on the back with a R1 on the front. However, it is about 3 mm out of round and goes thump, thump down the road. Schwalbe North America was not helpful and wants you to jump through hoops to get it warrantied. One real good thing is that you dont need tire tools to get them on or off. They are fast and light.
We have not experienced any issues with the ZX tire - if you purchased them from us and have an issue like this we would replace it for you - ed