I like this :) 18km/h is a little low imo (looking at my strava stats I'm usually just over 20km/h on my commute rides) but it's a good idea to add a limit

Couple remarks on the website itself:

- enable SSR if possible, having to enable javascript for a static website is annoying

- I guess you created this website on a mac? Be careful with scrollbars when you do; MacOS hides scrollbar but other OS don't and you easily end up with multiple useless scrollbars (like here with 3 unneeded vertical scrollbars)