Originally Posted by Mtracer

Not sure what is appropriate pressure with tubes, but with tubeless it is likely around 70 PSI. And keep in mind the penalty for lower pressure is very small while going above optimal the penalty rises very quickly. So, erring on too low is better than too high. And what the heck, it's more comfortable too. I probably already said this, but I run my GP 5000 S TRs at 58/61 PSI (front/back) on my Domane and I weigh in around 190-195 lbs. So, more like 220 lbs total, bike etc.



I agree, it's 6 mm and there is that extra resistance which makes it feel like a 6 mm doesn't fit. I generally just leave the supplied lever in the rear, and use a 6 mm hex wrench in the shop on the front.