Suit you sir. But which one, there's so many? Over the last couple of years mountain bikes have lost their monopoly as the only type of cycle to offer more gears than most of us have fingers and toes. Road bikes have never been built with more choice. That choice comes from the trio of variant in chain sets. To state the obvious, chainsets are driven by a cyclists’ legs via the pedals; the size (measured in teeth) of that chainset plays a huge part in your gearing and consequential speed.
Double - as the name implies, a double chainset is two chain rings, typically 52 and 39 teeth, feeding a range of gears at the back, known as the cassette. A double chain set is likely to be light and offer fast shifting. Doubles are often the preferred choice of the seasoned cyclist who may think of it as the purest offering.
Note: Cassettes tend to be geared from 11 teeth (the smallest, hardest and fasted gear) through to 27 teeth (the largest and easiest to pedal – theoretical 1st). For example, my Specialized Allez Sport (27 speed) has a 12 to 25 tooth cassette.
Triple - three rings, typically 50, 39 and 30 teeth (mountain bikes are smaller: usually 42, 32 and 22). Power is comparable to the double but with an added smaller ring for steep climbs. Changing down to this ‘granny’ ring because of a lack of thigh muscle is when the purists may frown. Three rings makes it a heavier choice and asking the front mech to move further means shifting wont be quite as swift (I’ll be amazed if you notice though).
A triple is ideal for mountain bikers who are used to the set up and for anyone new to road cycling and finds climbing difficult. Wait there; surely that’s everyone bar L. Armstrong? Yes it is, and that’s why a triple is a popular choice. My Specialized Allez Sport runs Shimano Tiagra 52, 42, 30 – I guess that makes me a lightweight then?
Compact – back to just two chain rings here but these are typically 50 and 34 teeth. The big ring is fairly normal but that small ring is smaller than you’d find on a double. This gives the rider an easier set of gears in which to climb.
I hope this helps rather than confuses you further.
