Challenge Gravel Grinder Race Tire 700 x 38 Tubeless Folding Black Road Bike 02004

Very light so far very durable. I have hit some pretty rocky sections on these.;

Very light so far very durable. I have hit some pretty rocky sections on these.

Bought two tires mounted both no problem used Stans sealant.
One tire held air fine the other started losing significant air pressure immediately. I felt unsafe to ride on it and returned it (air leaked through the sidewalls I assume and rolling Stans sealant around it didn't fix it).
Better quality control needed.
For the one that works--great tire great rolling resistance and cornering.;

Purchased to replace a another gravel grinder with a damaged sidewall. They are light and run great with tubeless set up. Hopefully the damaged sidewall is an aberration. If it happens again IÔøΩll be moving on to other options.

This tire has been awesome. I have put in 180 miles so far and one cyclocross race and no issues. I use it as a front set up tubeless and so far no flats. Grass and hard pack dirt are where it shines. Gravel has been really good as well but when it gets loose in turns it does slip a little bit but that is what I was expecting so I do not use it in races where there is a lot of loose dirt gravel in the turns.
Setting up tubeless was really easy (DT swiss spline wheels) it took two blasts from my airshot and then some topping off and I was ready to go. After 75 miles I had to replace a valve and I was able to re-seat the tire with just a floor pump.;