I have a couple of bikes and tire sizes. Some have presta valves some have schrader valves. I find the the tires that have presta valves hard to pump and that they seem to lose air way more often. Why do newer bikes and most high end bikes use presta valves? Other than being "newer" and I guess more "high end" what is the advantage? I can understand for road bikes. However, the bikes I ride most are gravel and commuter bikes with 700x35c to 700x40c tires. Does it make sense for me to just switch to schrader valves?
The easy way to fill a tyre with a Presta, also callled Sclaverand valve:
After unscrewing the small knurled top, give it a slight downward push to let some air escape. It will unseat the plunger. After that you can affix the chuck of your pump and the tube will fill in a breeze.
The bigger advantages of Presta are the lower weight (less imbalance in the wheel system) and the higher pressure resistance, up to 15 Bar vs 5-6 Bar for Schrader. Another advantage is that because of the screwed top they don't need a cap to prevent the ingress of dirt. The cap is required with Schrader both against leakage and dirt.