upgrade for commuting with kid? to what?
5 months ago I bought a Giant Sedona ST for commuting 7 miles each way on the road/bike trail. This was working fine and a few weeks ago I got a rear child seat and front rack so I could pick my son up after school and carry necessary gear. Picking him up adds 3 miles to the commute and his ride home is 8.5 miles. A few days ago I ventured onto more of a mountain bike trail than the bike can apparently handle (my son wasn't on the bike for that) and I don't think I'll be doing any more serious trails on this bike.
Yesterday I started to hear strange noises on the ride home with my son and when I got home I noticed that the rear wheel was wobbly. I took the bike into the LBS today and the mechanic found a spoke broken off at the hub. He suggested I avoid the mountain bike trail, which I had already decided myself. He also suggested that the components related to the rear wheel on this bike are not really up to the task of having an extra 40 pounds of weight in the form of my son (I weigh about 175 myself). Although I have been pretty happy with this bike, he suggested that it is typically used for lighter duty riding and less mileage. Since some of the parts on the bike are not easily interchangeable with higher quality parts, he recommends against upgrading individual components and suggested that I consider selling the bike and trying to get a better quality bike used on Craigslist.
So I guess my options are to:
1. Just keep riding the bike, with my son on board, and repair the wheel as is malfunctions, or at least wait until the next malfunction to take action.
2. Get a trailer to use instead of the rear seat. Issues: $250 already invested in rear seat and front rack, where would I lock up trailer? (is it an option to bring it with me to work empty and lock it to a bike rack?), I actually like having my son near me on the bike so we can talk, though I know many people think trailers are more safe/visible.
3. Upgrade via Craigslist. I am hesitant because I think finding a good deal here in Austin may be hard since I am not so bike savvy and many others trolling CL probably are. Also, I am not sure exactly what to look for. What type of bike would be more appropriate for a 17 mile commute through downtown/hike and bike trails, with kid on back for half the miles?
What would you do?