How to reload a model with additional query params?

I have model which has_many trains. After clicking some button I want to reload these trains, but I want each reloading request to be sent with additional query parameters.

Now I have something like this:

this.get('model.trains').forEach(function(train) {train.reload()});

which sends trains/:id requests, but would like it to send something like trains/:id?class=1

How can I do this?