How can I enlarge the fonts on Wikipedia in Chrome?

On most web sites, when I look at them with Chrome on my phone (a Nexus 4 running stock Android 4.2.2), I can adjust the font size by double-tapping a column of text to make it widen to fill the screen. However, this doesn't work on Wikipedia.org; I don't know why -- the text is quite small. I've already got the browser set up to display (very) large fonts: I'd gone to "settings", "Accessibility", and have cranked the "Text scaling" slider over to 155%, which is ginormous. (There's also a check in the box that says "Force Enable Zoom", which I don't recall setting; I guess that's the default). Anyway: this feature works fine on most sites, just not Wikipedia (and perhaps a few others). Any advice for making Wikipedia readable?