I have the Absolute Black 46 & 30 chainings on my Ridley Helium which is my climbing bike. Installing the chainring set gives me a deep range for 15-20% climbs that are common enough in southern Wisconsin. The oval shape may have some benefits, I do like the feel of the oval shape and I'm getting improvements on my steeper Strava segments. However, the primary benefit is the gearing. I like to keep my cadence above 65 rpms while climbing and these smaller chainrings along with an 11-32 eleven speed cassette keeps my legs fresh on longer days.
The Absolute Black chainrings install with an altered chain-line compared to the standard Ultegra 50 & 34 chainrings on the 6850 crankset. This can work on a rim brake bike, but I would not ever install these on my disc brake bike with 142mm dropouts. The chainline on the disc brake bike would be extreme while on the small chainring and several of the smaller cogs.
Even on the rim brake bike, the reduced chain-line is problematic. The front derailleur limit adjustment just barely aligned on the inner chainring. The chainrings don't shift as well, I have a SRAM eTap drivetrain which was always perfect with the SRAM crankset but is intermittently temperamental on the oval chainrings. Finally, the chainrings are noisy with a dry lubricant, but a heavy wet lubricant eliminated most noise.
BTW: Most current oval rings are are significantly different from Shimano Biopace design. I've ridden both, they are not in anyway comparable.
Originally Posted by
pippin65
Was wondering what you folks think of an oval chainring? Hype or help? I live in Florida but think that the big ring may help. Anyone have any experience? Thanks
Personally, I don't recommend the Absolute Black chainrings unless the user wants to change the gearing to help on steeper climbs if the bike has rim brakes. The benefits on flat roads at a higher cadence are minimal. The installation and shifting problems are significant.