Originally Posted by cyccommute

Not contradictory at all. They encourage stupid shifting patterns. Look at Phil_getz’s chart. A compact double is almost a linear gear ratio system. You could start at gear one (little-big combination) and shift up one gear at a time to the top. The problem is that you can’t shift a bike like that because (assuming climbing upwards through the gears) when you get to the top of the low range, you’d have to downshift on the rear 10 (or 11 or 12) times and then upshift on the front. A little over the top but not by much. Because of the giant hole in the middle of the ratios, you still end up with a double or triple upshift when you change range or you end up with a very high cadence to maintain speed and stay in a relatively close gear.

Modern chains aren’t all more flexible than other chain either. If anything they are more delicate with thinner plates, tighter tolerances, and prone to wear more quickly. Nor are they any easier to set up nor do they have more trim positions. My STI triples are dead simple to set up. They have the same soft second shift trim position as a double in addition to the third shift for the inner ring.

With my triple (or even a more traditional double), I have more duplicates but I don’t have to do multiple gear changes to maintain a more constant cadence. I also don’t need to use the big-big combination because it’s duplicated further down the middle chainring range.

Originally Posted by cyccommute

If you want to maintain a similar speed at a similar cadence, there is. Consider the following. The 50/39/30 with an 11-34 cassette is the gearing I have on my fast road bike. Comparing it to a 50/34 with the same cassette, let’s assume that you are riding in the 23 tooth gear on both bikes at 90 RPM on the same 28mm tires. Speed is 15.7 mph. If I shift off the large ring to the middle one, the speed difference at 90 RPM is 3.5mph. A slight increase in cadence will bring me back up to the same speed.

With the compact double the speed difference between the two ranges is 5 mph. To maintain the same speed, the rider has to increase cadence to over 120 rpm or the rider has to upshift twice to get the same speed/cadence as the closer ratio triple gives.


Road riders will go on and on about how they want close ratios so that they can find just the right gear for the right speed but then they ride a drivetrain that doesn’t allow for that kind of close ratios. I don’t get it.