[b.arci]

No team size is too big. The problem is not having enough active members. With more people, you can have more brain power working on something. In addition, you can grow your team's subgroups - for example you could start a website.

Every year, our team learns new things, and we update our resources so that other teams (and the following year's leads) can follow suit. However, if we had more active members, we would get things done faster (including designing and building our two robots/season).

Sidenote: Our team has 45ish registered students, with something like half of that active. On the side of our mentors, there are 15ish (who are all active), but they specialize in different areas. A few of them are there to be on our Board of Directors (yes, we are a community robotics team, who is a registered charity). When we were part of the local school, 10% of the students there were also on the team. Now that we are a community team, we have access to students from the Catholic school board (who make a 45 minute trek every day), home-schoolers, and students willing to make the trek from other nearby towns (although our numbers have not changed much—there aren't many students willing to drive 45 minutes each way).

TL;DR: More active members is better than more members, and you can grow your team into more than just robots.