Super boost is the latest frame standard that is slowly gaining momentum among mountain bike manufacturers. Currently used by Pivot and Scott Bikes, among a few others, super boost bikes have wider rear hubs and chainlines. This results in increased stiffness, strength and tire clearance. Super boost MTB chainrings typically feature 0 mm offsets for bikes with 55 mm chainlines. Let us explain what this means.
Super boost bikes feature 55 mm chainlines, but sometimes the chainline can be a wide as 56.5 or 57 mm. Specifically, chainline refers to the distance from the chainring to the center of the bike. Please see the image below.
Importantly, this 55 mm chainline is 3 mm wider than the more common 52 mm boost chainline. This wider super boost chainline can be accomplished in one of two ways:
1) Extra wide super boost spindle
With this option, the bike will typically use a normal boost chainring, however the spindle will be 3 mm longer, thereby resulting in a super boost chainline.
2) The bike can use a normal spindle but a super boost chainring
Here, the spindle doesn’t change, however the chainring does. Most boost chainrings feature a 3 mm offset. Offset is the distance from the where the chainring connects to the crank arm to the outside edge of the wide tooth on the chainring. Please see the image below.
Super boost chainrings however are perfectly flat. That is, they use 0 mm offsets. So by flattening the chainring, you are able to increase the chainline by 3 mm…from 52 mm boost to 55 mm super boost.
So in summary, the term “Super Boost chainring” refers to a flat, 0 mm offset chainring used on super boost frames.