Topic summary
Chainset
Extracted from the Wikipedia article Crankset.
Compact crankset
In the context of mountain biking the term compact crankset, or micro drive, refers to smaller triple cranksets, giving a small benefit in weight at the expense of increased wear and also giving the bike better clearance over obstacles. Typical ratios would be 22/32/44 teeth as opposed to 28/38/48 or 24/36/46 teeth. These would be used with smaller cassettes (Generally cassettes are available with 11 tooth minimum gear sizes for compact chainsets while standard chainsets were designed for cassettes with a 13 or 14 tooth top gear), giving the same overall ratio. Compact chainrings have been the dominant standard for mountain bike cranks since the mid nineties.