Cyclocross Tubeless Finale: Challenge H-TLR Tire Review with MilKit

Let's remember: (Somewhat) punctually with the start of the local cyclocross season, our long-term review of three tubeless-ready models that Challenge Tires offers for cyclocross also began. Chicane, Limus and Baby Limus each appeared in the H-TLR version to convince us of the merits of a tubeless setup in CX racing.
All technical details about the three review candidates, details on mounting including the Milkit Tubeless Conversion Kit as well as basic questions and beliefs around the topic of CX tires can be found in the Kick-off to the long-term review.

In the following lines I will try to draw a fair conclusion and to summarize the interim reports that have already appeared — in the form of comments under the above-mentioned article.
However, I must first confess one mistake: Of course the DT Swiss wheelset used was the ER1600 with a 20 mm internal width and not, as originally stated in Part 1, the PR1600 with an 18 mm internal width.

The various Challenge models were put through a rigorous but fair review over several training sessions and five races of the Austrian Cyclocross Cup. Unfortunately, they did not really impress. But let's take it in order ...

I would like to point out positively that each of the three reviewed tread patterns absolutely makes sense and choosing the one that fits the surface is easy. After all, there are some manufacturers who have so many different tires in their lineup that it becomes very difficult to pick the right one.
With the Challenge tread patterns, however, I never felt during races that I had chosen the wrong pattern.

Since most of the events I entered turned out very muddy, the Limus was always a safe choice here.
The tread has decent self-cleaning, and countless sharp edges provide massive traction paired with good braking efficiency. I also liked the tread on difficult slanted sections.

But this already brings us to the crux of the matter: A cyclocross (CX) tire depends on the right air pressure. Only when it's set perfectly can the tire perform at its best.
Unfortunately, however, we experienced sometimes quite substantial air loss with all three models, which we unfortunately couldn't definitively get to the bottom of. Sometimes the tires held their pressure almost loss-free, then there were races where the initially too-high starting pressure of 2.0 bar had already fallen to 1.1 bar after an hour.
So I started not just one race with little grip, and from halfway on had to fight to make sure the tire wouldn't be pulled off the rim ...

A look into the water bath showed: the junction between rim and tire is simply not airtight. And even at 2.0 bar, burping (that is, the escape of air at the rim/tire junction, which in practice usually happens in hard-driven corners or when riding at an angle) could already be simulated with firm thumb pressure.

The trouble announced itself already when inflating the tires. Almost every tire I’ve ridden in my life so far (and there have been many) popped into position with a loud bang when inflated. Not so the Challenge tires.
Also, these tires, when deflated, can be pulled off the rim again with almost no effort – surprising after the exertion during mounting.