Can I ride 20 miles when I've been only riding 10?

[HappyTexasMom]

Yeah I'm having 2nd thoughts. I really really really want to go, and I'm not sure I'm going to have another chance for a while (mornings are limited, early evening is too hot/out of the question, later evening I just don't feel safe alone, and I'll be going out of town soon). But I just went for a short 2 mile (albeit sloooooow) ride with my 8-year-old and my neck is really feeling it.

My saddle is level, I do have a visor on my helmet I could remove. I did talk to the bike shop once and now that I've learned a little more, I'm not entirely happy with the recommendations he gave me. Or rather, that he didn't give me more. He recommended adding a riser to the post, and possibly some handlebars similar to what's found on a hybrid bike. He didn't mention anything about moustache bars or butterfly bars (I'm thinking I *might* like butterfly bars for this bike). So I may try another place. I do know that any bars that give me significant changes are going to require new cables...which is more $$$ I'm dumping on what's essentially a crappy bike. I could almost just go buy a new (albeit also crappy) hybrid from Target (I know, I know, but this is a Sam's club bike) for not much more (considering I also need new tires...*badly*...and a full tuneup).

The problem is I really don't have money for a new *good* bike right now. And I certainly don't want to settle for something I won't ultimately be happy with, at least for a few years. So I'm trying to figure out how to tolerate this one until I do. I don't mind putting some money into it, but I hate to sink too much into it.

I have been watching craigslist, but don't feel that I know enough about bikes for that to be a good option for me. Plus I still have (want) to ride while I'm still in the shopping/looking process.

*sigh* why do I have to have such expensive interests? (the reason I don't have money for a bike is that I just bought a digital SLR camera...I got a great deal, but still, not a small chunk of change!)