In full disclosure I have been begging Panaracer to make this tire for a while now so when I finally got word this tire was in the works and was going to be tubeless compatible I got very excited. I have always been a fan of high volume yet minimal and fast rolling tread tires and I can say this one did not disappoint.
The two tires I received weighed in at 484 and 497 grams and when set up tubeless on Velocity A23's they initially measured 41.7mm but after a couple days of riding they stretched and settled on 42.3mm wide. Initial tubeless set up went as easy as one could hope for, on my A23's I used two layers of Velocity's Velo Tape and valves. Once I mounted everything up they snapped into place very easily with an air compressor, I did not try using a pump. When seating there was a nice confidence inspiring "snap" as the bead seated into place. The tires held their pressure as well as any tubed set up from the first day.
In my eyes this tire really shines in the gravel grinder scene. This is not the most versatile 40c tire on the market but if you want a tire that is really good at going fast on dirt and gravel roads I do not think you could do much better than this. This is the fastest rolling 40c gravel I have tried to date, it seems to roll slightly faster that my previous favorite gravel tire, the Clement Xplor. It also seems to have a more supple ride as well. I am not sure if that is having a little more volume, if it is the fact that it is tubeless or something in the casing, all I know is I really love the way it rides.
One thing I was very skeptical of was the pretty minimalist cornering knobs but in a typical gravel road ride it was never really an issue. On gravel you do not gain cornering stability through cornering knobs but rather volume. One nice surprise from the minimalist cornering knobs was the amount of stability you get cornering hard on firm surfaces such as packed dirt or pavement was some of the best I have ever felt.
The tubeless performance was all you could really ask for. They installed great, held air from the beginning with no initial loss of sealant, no flats yet and no burping even at lower pressures over washboard roads so rough I could barely hold onto the bars.
Overall this is my favorite gravel tire I have tried to date but it is not the most versatile 40c tire on the market. If you are willing to sacrifice some rolling resistance in exchange for climbing or cornering traction on loose singletrack you may want to look at other tires like the Panaracer Comet, WTB Nano, Kenda Happy Medium, etc.
Panaracer Gravelking 40c Specs:
Weight: Actual: 484/497 grams
Width: Actual: 42.3mm after settling.
Casing: Tubeless Compatible
Availability: These should be available through your local shop around December 2015.
More Info: Panaracer.com
**While I was provided these tires at no charge, Panaracer did not offer any compensation for this review**