I’ve been running a 30t absolute black chainring for a few weeks, with a sram 10-42 cassette. I can’t speak to the knee problems, but generally I’ve like it. I have the feeling that it increases the gear range a bit, however probably more true for those who climb with a lower candence- you can basically push a “harder” low gear, because it’s really only hard during the downstrokes. So yea, I think it’s an interesting pice of gear, but not a life changer.
I ran 32t Oval chain ring on a 10-42 Sram cassette and I found it slightly easier than the round version. Having 1×11 puts more stress on the knees and legs in general since you do not have the same gear ratio as 2×11 e.g. 26/36T chain ring on a 10-42 cassette. I just changed to this set up and I climb faster and don’t spin out on the down hills so quickly.
I’ve ran them for three years. I wouldn’t go back. I climb way faster leaving me less tired at the top. Zero knee or back pain. They allow you to spin with superior efficiency. Absolute Black and Wolf Tooth (the burliest of narrow/wide chainrings period) make great ones.
Ovals give a very slight advantage with climbing imo, especially when climbing slow techy rock. You are in the dead spot for less time and can put the power down quicker. Been on them 3 years and won’t go back to round. That said, wait till the round is worn before changing and don’t believe much of the hype otherwise.
For pedally stuff, like road or XC, it’s fine–no real complaints. Some people do get a benefit here, and that’s great. I just didn’t see it.
Where I found an oval chainring annoying was in pedaling transitions, which tend to happen a lot on the trails I ride. Transitioning from attack position to pedaling, from descending to climbing, or from left forward to right forward (for really techy stuff), I found oval introduced an awkward lag oftentimes.
@Zoso, I’m not sure what you mean by being in the “dead spot for less time.” For me, there is no dead spot on a round ring, but there is on an oval.
Dead spot: basically at 12 and 6 o’clock, where you have nearly zero power output. Hope that helps.
Gotcha, that makes sense for when you’re turning the cranks. I guess the dead spot I’m talking about is when you transition from attack position (3 and 9 o’clock) to pedaling–that’s where the oval introduces a new dead spot (or at least, a low power/slow spot) that round cranks don’t have.
@jeffbarber: “I guess the dead spot I’m talking about is when you transition from attack position (3 and 9 o’clock) to pedaling–that’s where the oval introduces a new dead spot (or at least, a low power/slow spot) that round cranks don’t have.”
If this actually occurs, either A. I’ve never noticed it, B. It wasn’t a big enough deal for me to notice, C. I was too enthused to give AF about the fact that I was climbing faster without being tired out or most likely D. I’m only an okay rider at the end of the day and such minutiae is of little consequence to my riding experience.
Haha, fair enough Dr Sweets. I can definitely understand the benefits oval has for pedaling which is probably why it caught on in road biking first. The tech handling bit is probably a minor tradeoff for a lot of people.
I have an Absolute Black oval and like it, but you do realize there are four or five slightly different off set degrees between the different manufacturers than can make them feel slightly differently.