You are right to not want to spend a lot on a gym membership. Research shows that about 90% of people who purchase one year memberships visit regularly for under two months.

The research also shows that you are far more likely to use a workout facility if it is within a couple of miles of either your home or your work. People just find too many excuses to not drive (or ride) across town to work out. Obviously in large part because a one hour workout becomes a two hour or more ordeal.

So if you have a YMCA or something close to home or work and you can pay by the month, it is worth considering. Otherwise the odds are that it is a bad investment.

By the way, you should be proud of the weight you have lost and that you are committing to lose more through exercise. If you start with "short" rides of five to ten miles it is o.k. For a lot of the people on here that is a "warm up" and they will be critical. Don't let nasty people discourage you. Do it for you and enjoy the gains (or is it losses?) you are making.