Single chainring setup for MTB: choose the best combination

autorRotor Bike Components
fecha17th June 2020

Single chainring for mountain bikes is common. It is the new standard. Yes, double chainring transmissions are still available, but single round and oval chainrings are the way to follow when you want to seek maximum efficiency, ease of use and faster maintenance. We will explain to you the options ROTOR has to help you choose your right setup.

Round or oval. Or as we like to say in ROTOR, 0% ovality in the case of round ones or variable, depending on the model of oval versions. Whether you are one of those who prefer the 0% ovality or if you are already convinced of the multiple advantages of the ROTOR oval chainrings, you have to take into account that the number of teeth on the chainring in combination with the cassette you run and the number of speeds it has, are essential to get the most out of the transmission.

The ROTOR single chainrings have the virtues of being made of 7075 CNC aluminum and offer a huge range in both the number of teeth and the types of fitment. In fact, ROTOR direct mount MTB chainrings are available from 26 teeth to 40 teeth. And they are not only available in direct mount for ROTOR, but you also have compatible versions for other brands such as Race Face, SRAM or Shimano, as long as you choose oval chainrings.

And if you do not have a direct mount system, with single round chainrings you have different options; on the one hand, the NOQXI range for 76mm BCD spiders and ROTOR, SRAM, Specialized and Cannondale F-Si Ai cranks, in 32, 34 and 38 teeth, and, on the other hand, the range with a 110×4 BCD that you can use with the ROTOR cranksets with INspider powermeter, in addition to the KAPIC, KAPIC CARBON, RHAWK and RRAPTOR. Available in 34, 36 and 38 teeth.

Likewise, for oval chainrings, at ROTOR we offer you a multitude of options for systems that are not directly mounted, as well as on round chainrings, for 76 and 110×4 BCDs. And in this range, there is one that stands out from the rest, the QXI 76×4 model that offers you 3 OCP ovality positions, with a 12.5% chainring ovality and compatible spiders for ROTOR, SRAM, Specialized and Cannondale cranks. F-Si Ai. You have this model in 30, 32, 34, 36 and 38 teeth.


At ROTOR we offer you our 1×13 transmission for mountain bike, road and gravel, but in addition to our 13-speed cassette (10-36, 10-39, 10-46 and 10-52), you have our option of 12 speeds (11-36, 11-39, 11-46 and 11-52). The good thing about ROTOR chainrings for 1x transmissions is that they are also compatible with 11-speed and 10-speed transmissions, as long as you choose the appropriate chain.

Considering that the market currently has a predominance of 11, 12 and 13 speed systems, it is very important that you choose the number of chainring teeth correctly. There is no general rule to know what number of chainring teeth you have to mount because you have to take into account not only the speeds you have in your transmission, but also the ratio of the cassette, your training level and the areas through which you ride.

Typically, on 1×11 systems where most systems use a 10-42 cassette in SRAM or 11-40 and 11-46 in Shimano, the chainring typically ranges from 28-36 teeth in most cases. Let’s say that the combinations with 26, 28 and 30 tooth chainrings are the easiest to move in all types of terrain and you can climb with a lot of cadence, but in flat areas or high-speed descents, you will notice that the development falls somewhat short. The 32, 34 and 36 tooth options are very versatile because you can use them both in Cross country, Trail, and Enduro. Somehow the 36 and 38 chainrings are almost for the sole use of experienced Cross country and Enduro. Moving an 11 speeds transmission with 36 and 38 tooth chainrings is not easy. In this sense, the oval options from ROTOR will help you notably to have a more fluid pedaling, less muscle fatigue and a higher cadence.

With 1×12 and 1×13 systems like our full ROTOR transmission, the most common cassette ratios are 11-46 and 11-52 for the 12-speed ROTOR cassette and 10-46 and 10-52 on the ROTOR 13 speed cassette. With such a wide cassette range, it is easy for you to gain at least two teeth on the chainring if you are coming from an 11-speed transmission. This range of cassette allows you to run a larger ring for all disciplines. So, a 32-34 is generally for all-purpose Trail and Enduro and in cross country it is easy for you to move a 36 or a 38 and for the most pros, a huge 40. In Enduro if you use 1×12 or 1×13 it is also an option to use a 38 if you are in good shape, but you will see that the most common is a 34 or a 36. Keep in mind that in this case we are talking about mountain biking; for road or gravel you can use our single chainrings with direct mount in our 1×13 transmission with chainrings from 40 to a giant 54.

The best of all, is that the options are so vast that being able to raise or lower two teeth on your chainrings can completely change the way you pedal. Whether you fall short descending, or if you notice that your climbing suffers too much, swapping out a chainring is not too expensive and in most cases if you do not add or remove more than two teeth in the new ring, you will not have to change the chain, if you adjust the rear derailleur. At ROTOR we help you find your perfect chainring for your 1x transmissions and we encourage that if you change chainrings, switch to the ROTOR oval ones and try a new experience that we are sure will change your way of pedaling forever.

Would you like to know more about the ROTOR chainrings?