I’ve been riding oval rings for 10 years. On road bike and mountain bike I have round rings. I’ve never considered getting rid of oval rings because I’ve always been happy with my speed per watt, and running afterwards.
Have a 1x 50 rotor, but I’m doing several hilly races this year.
Kind of want to go to axs 1x on my time trial bike. Either that or buy 2xrotors.
Any FOP people switched off of Oval rings and had any issues?
I switched to round 2 years ago after riding oval for about 5 years (Rotor Q and QXL).
The only situation where it is noticable is when going downhill or riding with tailwind where an oval ring allows you to ride a bit faster for same cadence compared to round with same amount of teeth. For me that is no deal breaker. When spinning out on 55-11 it is better to tuck down and hide for the wind 
Shifting is better on round. Impossible to drop a chain on a complete Shimano system.
Sam
I switched to round 2 years ago after riding oval for about 5 years (Rotor Q and QXL).
The only situation where it is noticable is when going downhill or riding with tailwind where an oval ring allows you to ride a bit faster for same cadence compared to round with same amount of teeth. For me that is no deal breaker. When spinning out on 55-11 it is better to tuck down and hide for the wind
Shifting is better on round. Impossible to drop a chain on a complete Shimano system.
Sam
That’s not how it works. The ratio is still the ratio.
The advertising campaign was about a 48 vs 50 and a 11 vs 12 cog setup. It’s just the math of the tooth counts that determines speed. Not the shape of the teeth around the ring.
I switched to round 2 years ago after riding oval for about 5 years (Rotor Q and QXL).
The only situation where it is noticable is when going downhill or riding with tailwind where an oval ring allows you to ride a bit faster for same cadence compared to round with same amount of teeth. For me that is no deal breaker. When spinning out on 55-11 it is better to tuck down and hide for the wind
Shifting is better on round. Impossible to drop a chain on a complete Shimano system.
Sam
That’s not how it works. The ratio is still the ratio.
The advertising campaign was about a 48 vs 50 and a 11 vs 12 cog setup. It’s just the math of the tooth counts that determines speed. Not the shape of the teeth around the ring.
No, I don’t believe the ratio is the ratio. A 55t Qring has the leverage of a 58t round ring at its widest point so part of the pedal cycle (where you apply most torque) will give you more speed for equal rpm. That is because you spend more time per cycle on the large diameter part and less time on the small diameter part. This is also the reason why crank based powermeters tend to exaggerate power on oval rings.
You can do this experiment easily on the indoor trainer. The more ovality, the higher the effect. With Osymetric it is even more clear.
The ration is only the ratio when torque is equal over the whole pedal cycle and that is not the case.
Sam
That’s not really how it works though.
What happens is that the oval ring, in theory, increases the effective gear at the strongest part of the pedal stroke, and reduces it at the weakest point, which allows the rider to ride in a bigger actual gear at the same cadence.
So if you have two 50t chainrings, and one has an ovalised shape, you effectively end up pushing a bigger gear? I have to admit I don’t get that (still in the ‘the ratio is the ratio’ camp here)… can you explain it further?
But that’s a physiological advantage that allows you to change gears, in their theory.
A 55t 12t round setup will spin the rear wheel the same speed as a 55t 12t oval ring setup.
If you think you can push an entire extra cog due to the ovality of the ring you’re talking a mega watt difference, where the real change is much more marginal.
If we want to play games about it, yeah, if saving 5w means you can shift gears to go faster…sure.
But the tooth counts and rpm’s still dictate the speed regardless of the ring shape. Period. Full stop.
I could change tires and tubes and gain 10w and suddenly be able to change to a different gear or a higher cadence in my max gear at threshold, yes. But that didn’t alter the actual top speed the bike could do with infinite rider input.
But the tooth counts and rpm’s still dictate the speed regardless of the ring shape. Period. Full stop.
That is absolutely true if you ride a fixed rear cassette. But in the (very rare) case where you push a gear 50% of the pedal cycle and coast 50% of the cycle you actually go faster as opposed to not coasting that part.
Also, if - when spinning out - the limiter is velocity in the power phase you might be marginally faster with an oval but in that case you will have a higher rpm compared to the round ring situation.
The only situation where this possibly applies is when spinning out at max rpm.
At 80rpm speeds will be equal between round and oval with equal teeth as other posters stated.
To go back to the OP: there is nothing you need to be scared of going back to round.
Giving well meant feedback on ST is sometimes hard…
Sam
But that’s a physiological advantage that allows you to change gears, in their theory.
A 55t 12t round setup will spin the rear wheel the same speed as a 55t 12t oval ring setup.
If you think you can push an entire extra cog due to the ovality of the ring you’re talking a mega watt difference, where the real change is much more marginal.
If we want to play games about it, yeah, if saving 5w means you can shift gears to go faster…sure.
But the tooth counts and rpm’s still dictate the speed regardless of the ring shape. Period. Full stop.
I could change tires and tubes and gain 10w and suddenly be able to change to a different gear or a higher cadence in my max gear at threshold, yes. But that didn’t alter the actual top speed the bike could do with infinite rider input.
Dont know anything about it, but wouldn’t your cadence go up a bit when you hit the “low gearing†of the chainring, less torque - higher rpm? And the advantage being that you dont slow your cadence as much on the High torque part of the stroke? - what I mean is similar to doing intervals on a smart trainer, my cadence dont drop when the interval starts, But when the power suddenly drops from 95% ftp to 40% ftp cadence goes up by 10-20rpms, But with oval rings on a smaller scale, so you’re not really changing the gearing But effectively increasing rpm with the same torque?
If you run 3 miles at 10:00 per mile and 1 mile at 5:00 per mile that is 35:00/4mi or 8.75min per mile. Same as running all 4 miles at 8.75min per mile.
Your cadence sensor counts each rev. It’s the total time per rev that matters. Or total revs per minute. If you rotate the crank 100 times the bike will roll out the same distance on both no matter how you decide to do it.
Take an oval ringed bike and round one and measure the rollout like you would to get a perfect tire diameter measurement.
The gain is supposed to be physiological or power based, not fake science gearing magic. The oval shape helps your body apply power more efficiently so you can put down more power.
I’m a fop age grouper by most standards. I’m usually in the top 1% in races and I switched from osymetric to round and didn’t notice a difference at all. Except I never dropped my chain anymore
My only issue going from oval back to round was that I started running better off the bike with round rings. Not a bad issue to have. ¯_(ツ)_/¯
I ran terribly off the bike when I had oval rings, when part of the reason I wanted to try them were the stories of folks running better off the bike with oval rings.
YMMV