What you need to do is work out what ’Gear ratios’ you like to use and then try and achieve them, making sure they are correctly positioned, no point if mathematically you can only get your most common used gear in largest ring largest sprocket.
By way of an example that is all I have done on my tour bike I use a 13-29 Campagnolo 10 speed set up with 26-36-46, which gives me all that I am after
In my case for example I like gears of around 60”, you will see that I have got those on both middle and outer ring. I have done this essentially because this is a bike I use for two roles, solo rides of 15-20mph and touring rides of 12-15mph, to save repeated chain ring changes I can essentially use the big ring mainly for solo rides and the middle ring for more sociable rides. Even though it only has a 96" top gear I find that easily high enough for a mid 20-25 mph work out, for 15-20mph cruising I have ratios that I like available mid cassette on the 46 ring, this I find is the perfect set up for me. Of course everyone is different, some prefer a lower low gear and a higher high gear, horses for courses as they say
It does take a bit of thought as to what you need both in terms of ratios and then equipment choices to achieve them, but it can nearly always be done. In my case for example I did invest in a high quality chainset to get the ring combinations I wanted, as for me personally I find many road specific triples to large for me and the ATB chainsets to small for what I want, where as with a compact 34/50 I find the ratios I want are in the wrong combinations, large ring large sprockets or vice versa.
Note I said 'wanted' not 'needed', my tour bike is used for tours, often I want to climb a long mountain pass with little effort to take in the scenery, so I chose lower gear ratios on that bike. Sportive bikes by comparison are normally ridden with no luggage, plus set up generally for riding at a higher speed than a touring bike, you can see from that gear chart above that a 34t inner chain ring with a 27t largest sprocket, a common combination on a sportive bike with compact transmission, will give a lowest gear ratio of approx' 34", on that style of bike that is low enough for most riders, even on a mountain pass.
To try and explain what a 34" gear ratio equates to you will see a red Audax bike in my tour write ups under my signature below, the ’Cycle tour from Lands End to John O'groats, (LEJOG) write up had a higher gear than that and I rode up every climb, in that specification I also toured the High Alps with two full panniers and again rode every climb.
However, I realised when I was riding in a group I had to keep the gear turning on the climbs and ride quicker than many of my new friends, who were using lower gear ratios than me and able to ride at a slower more socialble pace, that along with wanting to take in the scenery is why you will now see that bike had a triple in some of the later tour articles. As I said gear ratio choices can take some thought, the decision may not always be down to ability.
Note my bike is an Audax bike, I have mentioned it purely to illustrate the thought process that can go into deciding what gear ratios to go for. As an Audax bike like mine is often used potentially for slower tours, many spec' a triple over a double, where as some of the bikes you are considering are set up more as fast day ride/sportive bikes, as I said above normally used for a slightly faster style of riding, as such they will normally have higher gear ratios than my Audax bike as a result
Paul_Smith
www.corridori.co.uk
