>>1168476>Why do cheaper bikes use 21 speed gearsTriples have the disadvantages of being heavier, being difficult to index, and having many overlapping/crosschained ratios, but older mountain bikes used them in spite of the difficulties because in the 80's and 90's there was literally no alternative way of producing the required range of gearing.
With the advent of 9, 10, and 11 speed systems, it became possible to keep the same gear ratios with 2x drivetrains that previously required 3x. A 2x10 drivetrain can give you all the ratios of a 3x7, with fewer overlapping gears, lighter parts, and less complexity. This is why you don't see triples anymore except on touring bikes, which have the unique need for both range and closely spaced gears, or on cheap bikes because a 3x setup is still the cheapest way to produce a wide range of gears. cont...
