In the process of setting up my second CR 1600 Spline wheel set tubeless, I ran into the issue of the wheels not holding pressure again. The tubeless valves that DT Swiss provide with their wheels, or rather the gasket used, simply doesn’t seal well in those rims (the middle and right gaskets in the picture below).

For this wheel set I bought a set of Muc-Off Tubeless Presta Valves, which also came with three different types of gaskets. Being hopeful, I tried using the gasket that looked similar to the one supplied by DT Swiss and it was a failure, like last time. The tyres/wheels wouldn’t hold air well and my workshop smelled like Muc-Off sealant all day.

The solution was to switch to the biggest gasket supplied with the valves (pictured left). Even with the valve screw tightened down with less force, I got a proper seal immediately and the next morning the tyre pressure gauge showed the same 4.8 Bar I pumped the tyres up to.

Yesterday I took the bike out for a ride and everything worked perfectly with no pressure loss whatsoever.

Side note:
Apart from this issue with getting a good tubeless valve seal, the wheel set(s) have been incredible. Considering the amount of abuse I subject one of them to, it’s surprising that it still runs perfectly true. Really good value for money. Fitting most tyres (tubeless or tubed) is a breeze.