There are several of us here that have come back to cycling either for the first time- or after a long lay off. That means that fitness is not always there and the main worry is as to whether we can get the right gearing to keep us cycling. Have to admit that it took a long time to get the right gearing for me and that only came when I got a "True" Mountain bike. That gearing was 42/32/24 and with an 11/28 rear cassette.
Later MTB's had 44/32/22 and 9 spd 11/32 but those first years on the proper gearing taught me that i could get up the hills offroad and they never did get any easier- just faster.
When I went road bike- I automatically opted for a triple. 52/42/30 and 12/26 cassette although I did cheat when I climbed a mountain and put a 28 rear cassette on. Even though I was on slicks- on a road bike and I had all that strength from the MTB's- I rarely got out of the 42 at speed. The 52 came in for downhils and with strong tailwinds. Then 6 months ago I got a bike with a compact double crankset. 50/34 and a 12/27 10 spd cassette. Took a bit of training but I find I can do all the hills in 34/27 that I used to do on the triple with 30/28.
Then I recently got the TCR and this also has a compact but 50/36 and a 12/25 cassette. haven't tried the severe hills but I am doing hills up to 12% and without the leg strain I thought I would have. They are not easy but I haven't had to walk a slope yet.
So what is the best gearing for those of us in this forum? For those of us unfortunate not to have hills in the area- I suppose you only need a couple of gears and they will be quite high. If you have the gentle rollers that don't even get you out of breath- then you can still get away with high gearing but the problem comes about if you have the kind of hills that the car struggles up. Disregard the MTB offroad hills as they only require one gear- The lowest you can get- but you know the type of hill. You look at it and get ready dismount right at the bottom. That is what you feel like doing when you start them.
18 months ago- I would have said opt for the triple crankset and the biggest ring you can fit on the rear cassette.- Now I am beginning to wonder. Ok- I did have a certain amount of fitness behind me from Mountain biking- but I do wish I had gone for the Compact in the first place. Road hills I struggeled up with 30/28 on the triple- I still struggle up with the lowest gearing I can get on the new bikes. Difference is that the hills are faster. Cadence of 70 means that the hard work is over quicker with 36/25 than it ever would be on 30/28. And the leg strength is building back up again. Now wheres the 11/21 for my neXt trip Up Ventoux- I'll just make certain it is nowhere near my bike when I NEXT DO IT.