A question regularly asked in the Cycling Advice group is “are oval chain rings worth it?” or “do they hurt your knees?”. After some discussion with Absolute Black, a set of their oval chain rings arrived on my desk a few days later for me to put through their paces.
I selected the same ratios as I used currently, 52/36 for the new Shimano Ultegra R8000 4 bolt system although Absolute Black lists most ring sizes and compatibility with most chainset designs too. Note that there is a set of “bolt covers” available if fitting to the shimano crank that blends the big ring into the bulky design of the spider, which for this test I didn’t have. These are purely cosmetic. However don’t forget you’ll need chainring nuts on top of the rings if replacing a shimano ring set.
The packaging is simple, but stylish and to the point. It also has instructions on how to install the rings (tailored for each model of chainring, so it mentions the Torx T30 tool needed to replace the shimano part).
When holding the chainrings, the attention to detail is immediately obvious. The CNC’d pattern on the front (yes, you see those grooves on the outside of the bike) is there to give stiffness. When comparing them to the Ultegra R8000 52t ring I was removing, there was a small but noticeable weight increase by installing the Absolute Black part. Installation was without a hitch, I am particularly impressed with how well the arms of the chain ring meet the spider of the chainset. They’re a slightly better fit that the shimano genuine ones in my opinion, which often need “encouraging” on and off with a rubber mallet where the tolerances are tight. One thing not mentioned in the instructions is to readjust the height of your front mech. On my Specialized tarmac I needed to raise it by around 7-8mm. With the 52t ring, there was still some further height adjustment if I choose to go bigger in future. Then don’t forget to adjust cable tension if running a mechanical groupset. Fitting and adjustment took less then ten minutes in a workshop. All that’s left is to ride them.
I’m sure we’ve all heard the comments, like “they’ll make your knees hurt”, “shimano did those in the 90s and they failed”, and “your chain will slap around all over the place and your gears won’t work”. After fitting the rings during the day, I set off on my usual commute home which I’ve ridden well over a thousand times. For the first 300yds it was the strangest sensation, almost like when you have a wheel with all the spokes snapping and flexing round everywhere. But then I automatically changed my pedalling style. For the last couple of years I’ve been forcing myself to “pedal in circles” to be smoother in competition. It takes an amount of concentration and energy to keep this smoothness. This isn’t necessary with the oval design Absolute Black uses. As soon as I reverted to my lazier more natural pedalling the rings totally made sense. Climbing is an absolute dream! Even out of the saddle on bigger climbs, there’s almost no surging when each pedal gets to the 3o clock position in the stroke. You don’t get that “thrum thrum” noise of acceleration then deceleration when you’re running very low cadences out of the saddle. It’s almost completely smooth. A similar thing happens when you’re out the saddle in a sprint. No surging, the bike feels more stable at speed too when your cadence is lower. Interestingly, I used to be happy keeping around 90rpm in almost all situations with round chain rings. I now feel happier at around 80rpm with the oval rings. I find I am in the 52/11 more often than before (at a lower cadence) in sections I would have previously been a couple of gears up the cassette.
Shifting quality has been as good as with the original ultegra 8000 rings. It’s never missed a shift, never dropped the chain over or under the chainset, and it doesn’t rattle at the extremes or even when you run the gears you shouldn’t (known as crossing the gears, running the extreme big/ big or little/ little sprockets).
I’m 300 miles in to riding these rings now including my last ten mile tt of the year. I have suffered no knee pain at all despite the change in pedalling style I’ve actually found that I suffer significantly less fatigue in my legs after a hard training ride. In general my average speed has increased slightly since fitting them as well. Plenty of 18-19mph commute rides and my fastest time trial in 3 years despite other factors slowing me down.
In all I can’t fault these absolute black chainrings in any way. Excellent quality, excellent shifting, smoother, a little bit faster, less fatigued legs. Now I just need to buy them for my other bikes.