Welcome Peter.
Your 53/39 12-23 will do just fine once you get your legs and lungs back into shape for cycling.
I'm 66 (there are many others here older than me) and my main ride has a 53/39 and 11-23 setup and I haven't met a hill yet that I can climb. Been riding for 11 years.
Stop by the
50+ forum and say hello to the other old timers.
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The Lord is merciful and gracious, slow to anger and abounding in steadfast love. - Psalm 103:8
I am a cyclist. I am not the fastest or the fittest. But I will get to where I'm going with a smile on my face.