Ben has an interesting question about his gearing, he has recently changed his cassette for one with a close ratio to go with his triple chainset, he thinks he could go with an even a closer ratio cassette. We discuss the pros and cons of triple and compact chainsets and different cassette ratios.

Question:
I just switched my rear cassette to a 11/23 Shimano Ultegra 9 speed. I previously had a 12/26 9 speed (stock). My front gears are 30/42/52. My cycle is a Cannondale Sport Road 500. I ride a relatively flat area. After riding today using the new gear ratio for the first time I am wondering if I could have gone to an even more aggressive ratio with the rear cassette. Is the 11/23 ration good for relatively flat areas and would a stronger 11/21 be even better? I ride 25 to 26 miles daily for exercise and am a fairly strong rider.

Hi Ben,

You must live in a flat area; do you ever use the 30 tooth chain ring? I doubt it!

With a triple chainset, or even with a compact, you should only need a cassette which we call a straight through, this is one that starts at say 11 teeth and goes up by one tooth at a time. One of the points of having a wide ratio chainset is so that you can have a close ratio rear cassette. Of course, if you are touring with a tent, sleeping bag and all the other camping equipment in a hilly area, then you would want a wide ratio gearing front and back.

Ben if you are using the 52 tooth and the 42 tooth chainrings then you should consider gearing up to a 53 and 42 tooth chainset for your next bike, with a 11 to 21 tooth cassette. This would give you a bigger top gear while keeping your lower gears the same. If you are a bit worried about not having a low enough gear or you are planning on riding in another area, then it might be best to go for a 53 and 39 tooth chainset. These are the gears that most professional riders use in most races, on more mountainous courses they would change the cassette for something like a 11 to 23 or in extreme cases 11 to 25 or 26. Very occasionally professionals would fit a compact chainset, but this would only be for a very steep climb like the L’Angliru in Spain.

So the answer is yes, if you feel you are under geared and you are not using those bigger cogs then change the cassette or, if possible you could change the outer chainring for a bigger one or spend more money and get a chainset with a bigger outer chainring.