Challenge
These tires are simply a joy to ride. They are fast, supple, and confidence inspiring. Yes they are the hardest tires I have ever mounted to my carbon rims, but oh so worth it! After a few rides, I duplicated a 15 mile course over rough and smooth asphalt and 1200 feet of elevation. On the route I was 1.1mph faster with a normalized power 32 watts lower than I had been a week earlier on my old tires. As a heavier rider I ride the rear at 50psi and the front at 48 and they feel wonderful.
I use these tires set up with Vittoria Gravel Inserts and Orange endurance sealant - set up was easy, they hold pressure and do not leak sealant with this set up. On 24mm internal rims, these tires measure 47mm width and have a high volume with low weight. I can run lower pressures which makes for a grippy and comfortable set-up. They seem to roll as fast on the road as my previous WTB Byway 40mm (which were more like 38mm). In short, it seems like all upside: lightweight (especially compared to other tires in the *actual* size of 47mm), fast rolling, grippy, comfortable!
This is the third and final review of this tire. I have about 1000 miles on them and unfortunately the grip has worn off and they are starting to flatten in the center. The front tire is still in pretty good shape but the rear wore very quickly. Once the tread had worn off I discovered wet roads or very hot roads with some oil build up would cause the rear tire to slip easily. This caused more cautious riding than I had in the beginning. Due to fast wear and the lack of grip once past 500 miles I can't recommend this tire if you spend of your time on pavement. As a very light gravel tire for occasional use or for race only use they should do fine. I never had any punctures but I have a few small cuts that did not go all the way through. I have also noticed that the rubber compound seems to have hardened over time. I love the way the tire looks but for a everyday tire on mostly tarmac I would not recommend them. I am switching to the Pirelli Cinturato Velo TLR in a 700 x 35c. The Pirelli is a far superior tire in my opinion. Challenge could have a solid winner in this tire if they just made some changes to the materials used and added a puncture barrier in its construction.
This is my third set of these tires, I love them.
The first set were 33s, now I'm using the 38s. They are setup tubeless with Stan's Grail rims running at 40 psi rear, 38 psi front on a Trek Crocket (I'm about 170lbs).
I ride New England gravel roads, double track, cinder trails and single track and find the tires plenty grippy in all but the wettest conditions and tough enough for the bony single track sections. The tires have a supple ride feel and roll very well on those necessary paved sections that get to the next dirt segment.
