Elliptical chainrings

outfox

The LBS has just got a stock of these. Has anyone here used them? What's the boardsie consensus?

Mycroft H

I've used the old Shimano Biopace rings in the past. Never noticed a massive difference with them.

dermabrasion

Ive been running them 2 years now. I liked them (a lot) at first and now I can't say i notice them now. I have dropped chains on several races this year resulting in me getting dropped. When shifting from the big to the small ring under torque it has dropped the chain. Di2 might solve this. Put a chain catcher on, but no difference.
So, I think they are fairly good on TT bikes. If your up and down a lot on the front derailleur, leave them alone.

outfox

Thanks dermabrasion. Any idea what sort of gain you get? Do you think you get a few km/h more than with regular chainrings?

Quigs Snr

I have the Rotor Q's on my bikes.

According to my Powermeter's (various types). No gain at all. No worse either. There's talk of more efficiency etc... I can't tell any difference. They didn't make me worse, put it that way. Shifting is slightly subpar though... especially on SRAM Red.. absolutely horrible. Shimano Di2 is fine.

outfox

Interesting. If there is very little difference, you'd wonder why Wiggo, Froome et al use them.

Quigs Snr

Don't pay too much attention to the Wiggo / Froome thing... Wiggo was back on the round rings when he won the worlds this year, so it doesn't seem to make a difference to him. Whilst if they were proven to confer a real advantage and people were attributing Wiggo and Froome's recent success to them... well then Contador, Nibali, Quintana etc... would all be on them too.

I reckon it comes down to whether you prefer the feel or not.

I switched 5 of my 6 machines to them last year. Thought I was going better at first, but really that was probably the fact that I was training somewhat consistently at the time. My time trialling disimproved however. Difficult to say if the rings made that difference or was it just old age, but what bothers me is that the one night I did a TT on round rings, it was my best ride of the year. Didn't do enough testing either way to be sure. I am neutral on them.

It's like homeopathy medication e.g. arnica. Really there's no conclusive science, a lot of claims etc... but if you believe it does something for you, then knock yourself out. Lot to be said for the placebo effect.

Yarisbob

Mycroft H wrote: »

I've used the old Shimano Biopace rings in the past. Never noticed a massive difference with them.

Ahh that brings me back... They were a marketing ploy at the time at the tail end of the 80's ... The Shimano rep told me "Look son just fit round rings - these are all in your head"

Good to see the concept making a return ...!

Mechanic365

I used qrings and osymetrics, qrings are useless really because it's a very subtle oval

Then using osymetrics I would concentrate on the perfect pedal technique and found it easier to make it. People that I talked to who couldn't get used to them are the ones who usually peddled badly and didn't work on it.

As for power yes I noticed an increase but only when I was doing one leg sessions and cadence drills. The rings don't just increase power, you need to work with them

And for shifting I found the qrings and osymetrics worked very well with any of the SRAM YAW front mechs. It always shifted up without rubbing the big ring

TBH if you want to improve your pedal stroke just use those American powercranks on your training bike once a week and oval rings or not you will improve

learn

Quigs Snr wrote: »

I have the Rotor Q's on my bikes.

According to my Powermeter's (various types). No gain at all. No worse either. There's talk of more efficiency etc... I can't tell any difference. They didn't make me worse, put it that way. Shifting is slightly subpar though... especially on SRAM Red.. absolutely horrible. Shimano Di2 is fine.

P = FV should help explain why there can be no gain. For over 120 years engineers have been producing all types of expensive equipment as they attempt to compensate for the inability of natural pedalling to apply pedal power around 12 o'c and all have been unsuccessful. By using nothing more than your brain for a switch of pedalling technique you can apply maximal pedal power at 12 o'c when ever it's required.

death1234567

outfox wrote: »

Interesting. If there is very little difference, you'd wonder why Wiggo, Froome et al use them.

]
AFAIK they only really used them in races, for training they were using rounds.

iwillhtfu

death1234567 wrote: »

]
AFAIK they only really used them in races, for training they were using rounds.

Advertising pay day so if only used at races (cameras) and not whilst training.

full gas

Think you need to stop getting your info from christmas crackers, pros may use standard chainingrings while getting themself in the shape so they can actually use Osymetric chainrings, Froome and wiggins may actually get the benefit of the chainrings because they have the ability to turn over the gear, you may find you don't

Seweryn

full gas wrote: »

Froome and wiggins may actually get the benefit of the chainrings because they have the ability to turn over the gear, you may find you don't

That is some nonsense I must say. If you do not have the "ability to turn over the gear", just drop down a gear .

There is a number of various models of non-round chainrings. It looks like whoever tried one of them, just speaks from own experience based on whatever he got. As an example, the Biopace from Shimano has completely different geometry than most of other setups. I would say they give an opposite effect than expected, and they are pretty much useless in my opinion.

The idea of the non-round chainrings is to minimize the time spent in dead spots and maximize it in the peak force phase of the crank revolution. Does it work? Well, it makes the pedalling a little bit smoother, but nothing that would help you to set a world record. I personally like the non-round chainrings. I have been using them for over two years and will probably replace them with another set next year when these get worn.

darkvalley

This published study from a californian university suggests an improvement in performance from using eliptical rings. However I have some vague notion of reading somewhere that Rotor may have part funded the research.
http://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1107&context=kine_fac

bikenut74

I used a set of Rotor Q rings for a year and at first I was convinced they made an improvement particularly when I was climbing. I'm a heavy rider and struggle on canal bridges but when I was riding a long drag in the small ring I felt they helped me keep a smoother pedal stroke and therefore climb quicker. I noticed improvements on every climb I used them on but I was also training more and lost some weight at the time so the improvements would be down that more. When using the big ring in a race I was regularly changing gears because I felt overgeared. Rotor claim the eliptical ring has the effect of making a 53 ring a 55. When sprinting I thought it made the pedal stroke choppy, that said I still won sprints. There are 3 settings to adjust the rings to maximise the effect to suit your pedal stroke and I tried them all. I did also notice occasional gear changing difficulties and dropped the chain on occasion but that can happen any time and generally they ran smoothly. I use Campag Record. In the end I switched back to round rings and surprisingly didn't notice any difference. I was told the round rings would feel strange having used eliptical ones for a year but 2km down the road I would only know I had changed if I looked down. I can't say my experience of them was negative. Any differences could be attributed to a number of factors but they certainly didn't have a negative effect and may have had some positive effect.