As long as it's comfortable for you. I love my hybrid (7.2FX--I'm a Trek-ie too ) and rode it in multiple charity rides (i think 62 miles was my longest), but by the end of anything over about 40 miles I'm just plain sore all over. I don't think that's the bike's fault, per se, but the fact that I know there are things I could do to make it fit me better. I did end up buying a road bike recently because I had an opportunity to get something on closeout, but I would have kept on riding my hybrid if I hadn't.

So as you move on to longer rides, if things start to hurt (and maybe they won't--I hope that's the case!), your bike shop and folks here can probably help you figure out how to tweak your fit to make it better.