I wouldn't touch Tubus racks with a barge pole as their QC is rubbish ever since they stopped making them in Germany and outsourced them to some far flung place in the East. I bought an Ergo front low loader from
Wiggle. Had three of them. The finish was awful, the final one cutting me on the finger as I inspected it. There was a very sharp piece of welding swarf on one of the tubes that had been powder coated over difficult to see, but still lethal. My finger got a rather nasty cut. Wiggle were sh*ts to deal with. They eventually refunded me the cost of the rack but I've never used it as it is also bent ie not true/square. I haven't bought ANYTHING from them since.