As we expand our bike fleet we want to ensure we get the setups right. Our riders vary in experience and our tours vary in difficultly so getting the bikes just right is essential.
The big question which comes up is which crankset and which rear cassette.
So…cranks, ie what your pedals hang off – Standard (double) cranks are 52-39 (ie 52 teeth on the big chainwheel and 39 on the small inner chainwheel), compact cranks which are a more modern take and increasingly popular, are 50-34 and then there are triples 52-39-30 (there are now also semi-compact and all varieties but these will do for now!).
The bigger the number the heavier the gear, the smaller the easier – essential for hills especially somewhere like the Alps on our Hannibal expedition! These are hugely effected by the rear cassette (the sprockets on your back wheel) which can be anything from 11-21 to 11-34 (with a adjusted rear derailleur)
So for our riders what we are trying to do is ensure they have the greatest gear range available, especially when they get to the hills. Now you would assume that a triple will do this, and the truth is if you put the biggest cassette in conjunction with a triple it will. However a standard Specialized Comp Triple, a fantastic bike and the backbone of our fleet, which our riders have ridden and loved due to its range of gears comes with a 11-30 cassette. Therefore its lowest gear is obtained by being on the 30 on the crank and the 30 at the back, a 1 to 1 ratio which makes for a great granny gear, essential for long steep climbs. A compact crank can actually achieve the same result. The easiest gear for these will be a 34 on the Crank and a 34 on the rear cassette, again 1 to 1 and exactly the same output as the triples easiest gear.
So you may have first been put off by the fact that we aren’t running triples but the truth is you will have exactly the same ‘easy’ gear for those testing days in the hills! You will also have a little less weight and smoother performance. This also increases the compatibility of our bikes as compacts are much more common than triples ensuring easier maintenance and repairs.
This is a table showing the ‘output’ required for each gear combination. You’ll note the 30-30 and the 34-34 are the same. Therefore easiest triple chainring equals easiest compact with a nice big rear cassette!