I had a back injury and bought a BIKE-E recumbent bike which I rode for 4 years. I put about 4,000 miles on it and wore out the shifter twice because I found on a recumbent I rarely got to coast, I was peddeling at a pretty steady RPM and shifting a lot to keep a constant speed. I loved the seat but didn't like the bike so much. As soon as my back got better I sold the recumbent and bought a "comfort" type bike. A Raleigh Passage 4.0. 24 speeds and a front suspension. It took me 9,000 miles to wear out the running gear and last season I had it re-built and am still riding it about 5 days a week. Most of my rides are 20 miles and under and I enjoy every one of them. The bottom line is to just get out and ride, you will always find somebody faster and with more durability than you have so don't let that keep you from riding. You are doing it for your health - both physical and mental and its a wonderful investment whether you are competitive or not. When I'm not riding the one I love I love the one I'm riding and while I am "only" 70 I attribute me good health to regular bike riding and intend to keep it up as long as I can. Biking is a wonderful hobby but we aren't all put together to be racers so don't let your lack of competitive ability stop you from riding. Just get a good quality bike that fits your and climb on and go. When I do I can't stop grinning! See you on the trail!
8-)