I wouldn't say it's safe exactly, not perfectly, but it would be difficult to turn this into an exploit, and also very unlikely, given the lack of any benefit to doing so. Hackers have greener pastures. On Velobase there's no e-commerce, nowhere you're going to enter your credit card, SSN or other monetizable data.

The main advice I'd give is to make sure you don't share passwords between sites, so if one is compromised, they don't get your password to other sites, including ones you'd care more about. Like your bank, Paypal, 401k etc. Editorial: Every grown-up should have a password manager, like 1Password, to ensure all PWs are unique and strong, and you don't have to remember them anymore.

Apologies for the off-topic bla-blah, I know this isn't the Internet Safety forum. I'd just hate for people to miss out on all the good stuff there on Velobase.