PREMIUM OVAL ROAD 2X FOR R9100 & ULTEGRA R8000 Premium oval road chainring for R9100 & Ultegra R8000 absoluteBLACK Premium Shimano 110/4 bcd compatible oval chainrings are designed for new type of Shimano cranks Dura-Ace 9100 & Ultegra 8000 only. These are finest oval chainrings on the market in terms of shifting, smoothness of pedaling and manufacturing quality. (They can be also retrofitted to 9000 and 6800 cranks). 10/11/12spd compatible. Size (Mass +/-1g): 34T (31g), 36T (37g), 38T (41g), 39T (42g), 50T (120g), 52T (137g), 53T(139g) Compatibility Shimano Dura-Ace 9100, R9150 Di2 and Ultegra 8000, R8050 Di2. They can also retrofit 9000 and 6800 cranks but use bolt covers for best appearance. 10 / 11 / 12spd compatible. BOLTS For Outer chainring please order "Long bolts" from us OR Bolt Covers Changing Inner chainring to oval only? use original bolts Material & Finish cnc machined 7075 Txxx Aluminum. Long-lasting construction. Type II anodizing Ovality Optimized to each size separately. 34T- 6.5% ; 36T, 38T, 39T- 11.4%, 50/52/53T - 10-11.2% ; Timing of 108 -110.5° after TDC (top dead center) - Ideal for road climbing. Patent Pending IMPORTANT Ramps on big rings are specially configured for combinations: 50/34, 52/36, 52/38, 53/39T If you wish to use other configuration it will also work, but shifting will be slower and may require more "adjustments" of front dérailleur to be acceptable. Also remember that front dérailleur can only accept max 16T difference between 2 chainrings - this is how Shimano and Sram designed them. Advantages of Absolute Black Road Oval chainrings: *One of a kind special oval shape that helps you climb easier and faster (Patent Pending) *Over 15% stiffer than Rotor Qrings due to thicker, 5mm construction *Bespoke Absolute Black 6 point ramp and recess shifting design shifts better than any other brand and model of oval chainring *Finest design that provides excellent strength to weight ratio *You will not "feel" the oval shape while pedaling *Your pedaling action will feel smoother *Helps reduce stress on knees and helping your legs remain fresher for longer *You will be able to maintain better cadence while climbing *Reduces possibility of leg cramps *You will reduce chainring/cog shifts by at least 15% What size should I choose? * 34T inner chainring should be used with 50T outer ring. It has 6.5% ovality. Use a 34T to help with spinning higher cadence and hilly terrain. * 36T inner chainring can be used with 50 or 52T outer ring. It has 11.4% ovality. Use a 36T if you’re a strong rider or for rolling terrain. * 38T inner chainring should be used with 52T outer ring. It has 11.4% ovality. Use a 38T if you’re a very strong rider or for flat terrain. * 39T inner chainring should be used with 53T outer ring. It has 11% ovality. Use a 39T if you’re a very strong rider or for flat terrain. * 50T outer chainring – Choose this size if you ride for pleasure or sportive events. This is the most versatile and comfortable size. * 52T outer chainring - if you race and feel strong, it's the classic outer chainring size and a great option for experienced riders. * 53T outer chainring - if you race and feel very strong, it's the classic outer chainring size and a great option for powerful riders. Remember when selecting your chainring sizes - it's not about what others use, but about ensuring YOUR ability to maintain a comfortable and effective cadence across the terrain you ride most often. If you ride chainrings that are too large (round or oval), your cadence will be lower. This can affect your performance by prematurely tiring your legs and possibly lead to stress injury in your knee joints. Shifting quality and technology Both, inner and outer oval chainrings are optimized with smooth shifting in mind. This is why the back of the Absolute Black Oval road chainring does not feature cutouts, like other oval products on the market. Instead, we design smooth angled surfaces, to help chain to slide quickly and precisely between chainrings. Absolute Black outer oval chainrings have 6 up-shifting ramps, for easy and quick gear change, even under load. Each outer chainring also features 12 down-shifting points. Instead of steel shifting pins we use a CNC machined "ramp and recess" solution. Special raised ramps work in conjunction with the tooth recesses to stabilize the chain when shifting. Our oval chainrings DO NOT require any modification to the front dérailleur in order to work properly (apart from small standard adjustment) Why our oval chainrings work Our premium Oval chainrings work because riders do not produce power evenly through a pedal stroke –the musculature of human legs makes it difficult to maintain an even power delivery to a round chainring. Believe it (or not), but a round chainring doesn't transfer torque to your rear wheel as smoothly as an Oval one. Oval rings work with the natural human physiology. Oval chainrings maximize the part of the stroke where power is produced and minimize resistance where it isn't. As a direct consequence, Oval rings enhance a cyclist’s ability to spin with a smoother power delivery and feel easier on legs while climbing. You will actually feel your pedal stroke to be more "round" with an Oval chainring than with a round chainring. Why using AbsoluteBlack oval chainrings matters Absolute Black oval road chainrings deliver power more smoothly to your rear wheel. This means you are better able to generate and maintain, constant cadence. Because oval chainrings reduce the peak loads on knee joints, riders using them get less stress on the joints (knees) and therefore are able to keep certain level of effort for longer. This results in higher average speed. You don’t need to take our word at Absolute Black; 11 scientific studies by leading universities around the globe show that; in comparison to round chainrings, when using oval chainrings, human legs utilize more muscle groups - but each of them to lesser degree. The overall Load from pedalling an oval chainring is spread over greater muscle mass. This has three key benefits; firstly, it gives you the feeling of fresher and more relaxed legs. Secondly; it allows you to achieve higher average speed riding uphill. Thirdly; spreading the pedalling load over more muscles reduces the risk of cramp, even when riding hard. The compound effect of switching to oval chainrings; the relaxed legs, added climbing ability and reduction of cramp means your overall enjoyment of the ride is enhanced. Why our Oval chainrings do not have adjustable timing At Absolute Black we have extensively studied the relevant performance data regarding the optimum percentage of ovality, shape and, critically, the timing of the oval – the positioning of the high and low points of the oval, in relation to the position of the crank arm and focus this into one single mounting position – this is the really important part of what makes Absolute Black Oval chainrings so effective. By simplifying our oval chainring design, to reflect a single high performance ‘sweet-spot’, we are able to make the process of fitting Absolute Black oval chainrings faster and easier, as well as making our rings even lighter. Can I use only small oval chainring and keep big one round? (and vice versa) Or should I use both oval rings? There is no problem using two different shaped chainrings mounted to one crank from mechanical and biomechanical point of view. However, please remember that oval chainrings are most effective in two situations; when you pedal uphill and if you don't have perfect pedalling action. We recommend using small oval ring as a starting point. Many professional riders switch to using an oval inner chainring for races with hard climbing – even when their equipment sponsors do not make an oval ring – knowing that it cannot be seen tucked behind their sponsors outer round chainring. When it comes to the style of outer chainring you need to answer two questions: * How often do I keep riding on big ring over smaller, less demanding climbs? If the answer is "often" then fitting an Absolute Black outer chainring is advised to gain the maximum benefit. However, if the answer is "very rarely" then keeping your existing round outer ring is a way to save some money. * Do I have a perfect pedal spin? This is an important one. Professionals and semi pro cyclists spin perfect "circles". The rest of us often struggle with our pedalling action, simply because we don't spend every day of every week on the bike, to master this skill. Switching to oval rings effectively correct an imperfect pedalling action – delivering the smooth power delivery the pros developed through thousands of hours of training. One of the key reasons the benefits of oval chainrings have historically proven hard to prove in lab tests, is because they were nearly always done using Professional riders – as a user group they are the least likely to gain a performance increase from a switch to oval, as their pedalling is already close to perfection. Where ovals shine however is with rest of us, who ride for pleasure and not for a job. Simply 99% of road cyclists will benefit from having oval chainrings on their bikes. How to mount 110/4 9100 / 8000 Oval chainring: (same instruction as for 9000/6800 cranks) First, you need to remove your crank from your bike. Once removed, unscrew the 4 bolts that hold two chainrings together with a T-30 torx key. Remove both original rings. Locate the new oval inner chainring with the triangular timing indicator positioned behind crank arm. The bolt holes on the small chainring are recessed – so the nut heads will sit flush with the surface of the chainring - these recesses should face you when mounting the bolts. Absolute Black outer chainring has a specific shape of mounting tabs so it will only fit one way on the crank arm. If you are only switching the inner chainring to oval - use the original bolts that came with your crank. If you are switching to a pair of oval rings, you will need a set of regular ‘double’ chainring bolts or our set of Bolt covers. Tighten all four bolts with force of about 5-7Nm. Mount your crank back to the bike. You may also need to adjust the front derailleur slightly. Absolute Black always recommends using a new chain when fitting new chainrings. All Absolute Black products are designed in UK and manufactured in Poland (EU) to the highest standards of quality. 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. The oval chainring movement across all cycling disciplines is growing rapidly, led by absoluteBLACK, the world leaders in this important product category. However, not all oval chainrings share the same performance characteristics as absoluteBLACK. The 'clocking' (timing) and shape of the oval are the most crucial parts of any oval chainring design, absoluteBLACK spent three years in design development and have perfected both timing and shape design elements - ensuring the ride quality of absoluteBLACK oval ring will be different and superior to ovals from other brands (as many abosluteBLACK customers already realised). Where most other brands retain the same timing (position of the crank arm relative to the oval) and shape of the oval across all their sizes - because it's cheaper and less time consuming. absoluteBLACK believe that each different size ring requires a bespoke, optimised, perfect pedalling solution. So that is what we do - for every chainring absoluteBLACK make. For example, the smaller the chainring size, the bigger the ovality has to be to help climb steeper hills more effectively. We keep our exact Patent Pending data a secret, to ensure we get the best possible absoluteBLACK advantage over other brands, and you get the best possible ride experience. Our longterm belief in oval and development of our design, has led absoluteBLACK to become the most commercially successful oval chainring product in the world. So keep in mind that not every oval chainring is equal to an absoluteBLACK. The World's finest oval (elliptical) road chainring. Non circular chainrings, Non-round chainrings. Asymmetrical chainrings.