Adding to the growing list of replacement chainrings for Shimano cranks, absoluteBlack just released new oval options. Created for the Shimano Dura Ace 9100 and Ultegra 8000 cranks, the rings have the necessary proprietary BCD (Bolt Circle Diameter) to match. While the new 9100 and 8000 series are the new hotness, the rings will also work on Dura Ace 9000 and Ultegra 6800 cranksets which have the same BCD.
Machined with their now signature outer surface to remove as much weight as possible while keeping the rings stiff, the oval rings use an updated shift ramp design on the inside which promises better shifting up front. Machined from 7075 Txxx aluminum, the rings use a Type II anodizing and have ovality optimized to each size chainring – 34T- 6.5% ; 36T, 38T, 39T- 11.4%, 50/52/53T – 10-11.2%; Timing of 108 -110.5° after TDC (top dead center).
The outer rings which are offered in 50T (120g), 52T (137g), and 53T(139g) are available in Black, Grey, and Champagne colors. The inner rings however, are only available in black and in 34T (31g), 36T (37g), 38T (41g), and 39T (42g) options. Rings are priced at $61.95 for the inner and $124 for the outer.
They’re not required, but absoluteBlack recommends their crank bolt covers to complete the look which feature a special outer bolt cover and smooth out the transition between the crank and the chainring. Machined from 7075 T6 aluminum, the bolts use a T30 Torx fitting and claim to weigh 13g for the set. These will add another $52 to your order and come in black or Ultegra grey.
The chainrings are shipping today, while the bolts will ship starting January 15th.