AbsoluteBlack shifts into Premium Oval Road rings for Shimano Dura Ace 9100 and Ultegra 8000

Written by Zach Overholt Jan 05, 2018 11:10 a.m. ET

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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.

AbsoluteBlack.cc

Zach Overholt

5,630 articles

Zach Overholt is the Editor in Chief of Bikerumor. He has been writing about what’s new in the bicycle world for 12+ years. Prior to that, Zach spent many years in the back of a bicycle shop building and repairing nearly every type of bike, while figuring out how to (occasionally) ride them.

Based in Ohio, Zach is now slowly introducing a new generation to cycling and still trying to figure out how to fit the most rides into a busy schedule as a new dad.

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Nick

6 years ago

Wish they would make both round and oval ‘rings on top of offering ‘rings for Campagnolo… bummer :/

Shafty

6 years ago

Reply to Nick

If you want round rings, just buy the stock replacement….right? Ditto for Campagnolo. Dura-Ace front shifting is unreal these days, so there’s not much reason for companies to make aftermarket rings, outside of cost, which is a ridiculous argument when you’re riding top end stuff.

Are oval rings possible with the new Campagnolo cranks? Can’t remember what the bcd is, but maybe there’s not as much ovality possible. Tiny market for that anyways.

Volsung

6 years ago

Reply to Nick

Aribike makes oval campy rings. Their website is horrendous though and I’m not sure how the quality is compared to Absolute Black or Wolftooth.

Bike rumor has had a few write-ups on them.

Chris

6 years ago

Thanks Shafty but the after-market should cater to niche markets; for example: oval Campagnolo rings. And since no company can make better round rings than OEM offerings is it okay to pine after OEM oval rings? I want to check before I receive a witty rebuke on the dissonant comments section via bikerumor.

Charlie Boyd

6 years ago

Reply to Chris

One would assume that receiving a witty rebuke on the dissonant comments sections is in fact quite normal and expected especially when asking a question that could have been easily answered by searching the manufacturers website before posting a comment on said website.

6 years ago

Man, that proprietary BCD is such a great innovation. Way to go Shimano!

Jimmy

6 years ago

I’ve ignored oval rings because of the bad taste left from “shimano bio-pace” years ago. Thought I’d look at these initially because they looked like they’d be a bitch to clean…
Apparently they are reselling “ovalized chainrings”, it’s interesting that they post the ovalization specs: “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).”
Has anyone seen modern ovalized chainrings compared to Bio-pace chainrings from the past with data provided?
Do they still kill your spin? Is history repeating itself?

Thomas Chapman

6 years ago

Reply to Jimmy

From Absolute Black website:

Word on BIOPACE – Please understand Absolute Black’s oval design IS NOT ‘Biopace’ technology. Shimano created their non-round Biopace chainrings with a completely different orientation of the biggest radius of the oval. Their ring orientation has since been widely accepted as being fundamentally wrong. Instead of positioning it in power zone – which is slightly below the level of the crank – they clocked it to the dead zone where human physiology generates least power. The result was that in power zone pedalling was too easy and in dead zone too hard, causing knee pain and lumpy pedalling cadence. Exactly opposite to how it should be. The opposite of how it is with an Absolute Black oval chainring fitted to your bike.

I appreciate that there is no data, but there is very little data for oval full stop. None-the-less, it’s pretty different to bio-pace

6 years ago

Reply to Jimmy

I have not ridden absolute black oval because there are studies that say their timing is all wrong. I believe these rings will kill your spin. Also the low percentage ovals are basically not noticeable. Per the studies I read timing should be about 65 degrees so the long axis is pulling when your legs are at full power and leverage.

Mike

6 years ago

Reply to ed

Kill your spin and not noticable?

Pinko

6 years ago

Just a copy of the ROTOR rings I have been using for years.
All the info I have been reading on their site don’t have any data to back it up.
They claim they have been researching oval shapes for years, but as far as I know they made the first oval a couple of years ago, well after Rotor and others (one up, leonardi, frm, carbon-ti, stronglight etc etc.)
I have been using non round rings since biopace, which ab like to bash on, but I am sure they were not old enough to ride bikes in the 80’s. Biopace won TdF, Xc worlds etc etc. Back then the pedaling style was different than nowadays ie not round, and lower cadence/more mash. The only reason shimano abandoned biopace (which was not oval but asymmetric) was when they added synchro shifting to the front derailer and it was difficult to avoid chain drop.

The rotor style shape needs to have options on where to clock the ring, as rotor does. Claim there is a perfect shape and clocking is like claiming there is a perfect handlebar height or width for everyone. No sense. I rode the AB rings and I found their clocking to be average and suitable to beginners. If you go fast or race, the clocking needs to be way more aggressive.

Mike

6 years ago

Reply to Pinko

Not really, adjustable clocking is perfectly reasonable and an improvement over fixed positioning given the wide range of seating positions and body proportions that different riders have.