I'm 51 and ride in hilly southern KY.- [I use straps- not clipless]- Started riding a year ago. I didn't seem to be making any improvement in speed for the first 9 months- but during the winter, I bought an indoor spin bike and started doing Tabata drills [Google it] and speed increased IMMEDIATELY on the road bike!! [You don't need a spin bike to do Tabata drills- you can do them on you bicycle (in a quiet area or big parking lot; etc.) or running, etc.].

It sounds easy. It's not. But it's over with fast...and I can not believe the difference it has made! Not only am I faster...but it made the hills a lot easier- and I'm now riding a standard double instead of the triple I started with.

Give it a try- you'll see results in a week or two- and it'll cost you nothing- and will build your cardio and lung capacity like nobody's business!