what is the thinking behind them? they look uncomfortable to use (do you feel the raising and lowering of the chain when you use them?)
biopace was slated by most back in the day,so what's the difference with these?
biopace went 'big' at the wrong point in the pedal stroke.
I think as far as pedalling - the effort required is concentrated at the point you have most mechanical advantage due to leg position.
wonkey rings are the new niche...... 😉
haven't used Biopace, have used an oval ring (from Tazzy) on my singlespeed.
I don't notice that it's oval at all while riding. If i understand right the intent is that where your legs are strongest, there is less mechanical advantage so you use more leg power / less leverage compared to where your legs are weaker and you get more leverage.
The only effect I've noticed is that I'm happily riding a 34T front whereas my round ring was 32T.
Many years ago I had a Dawes that came fitted with biopace chainrings. They were truly awful and I always felt like I was pedalling in a jerky manner when riding on them. It was a relief to get some round chainrings on there. Shimano really got their bio pace stuff wrong.
They are Rotor Q-rings. They have the extra teeth 90 degrees out from where biopace had them so they actually work unlike biopace.
so they actually work unlike biopace
Well do they? I mean if they definitely worked more pros would use them right?
They did a 5 minute piece specifically on this on the ITV4 highlights last week which might still be available to watch.
One of the issues they have with those rings is throwing chains off occasionally but some riders think that the advantage is worth this increased risk.
Had Biopace rings on a commuter/tourer. Kept them for a few months, didn't even notice.
The ones Wiggins uses are Osymetric not Rotor Q rings,
If anything the Osymetric appear even more oval than Rotor Q rings 😯
The one thing I have heard is that Q-rings are not oval enough to make a real difference. I used to use them, gone back to round rings now, which I prefer.
Tried a Q-ring, caused pronounced bobbing on an FS.
May have got better as I adapted but I felt it wasn't worth the effort or cost of getting all the bikes set up the same.
what Keef said
People have been playing with these since the 1890's and they still are niche. There is a lack of evidence that they make a real difference.
Boardman said they were nonsense, which is good enough reason not to use them for me!
I'd like to try them on the road bike (based on using them on my SS where I'd say there is a subtle benefit), but not sure I'd notice it as much when there's a choice of gears.
I mean if they definitely worked more pros would use them right
Depends on who sponsors them. For the rest of us it's a big ask to shell out £200+ to try something with marginal gains. On a SS it's only a minor gamble.
It might just be psychological tbh- which is a better reason to use them than most.
^ true.. or it may just suit the pedalling style of some more than others. I'm definately not a natural spinner and have become more of a churner on or off-road since riding SS more regularly in recent years, so the variation in gear may work better for me.
Dave wouldn't use them if they didn't work, he's also one of the countries foremost Biomechanical 'enigneers' so he's got a rough idea of how the body and kit works.
They're different to biopace as setup differently.
The first generation Biopace had very little ovality on the 48T rings, some on the 38T and a visible amount on the 28T.
Later versions has more ovality across the range.
I had them (GS200s) on a 1989 hardtail and you simply did not feel any difference on the road.
Front mech (GS200 and LX300) was fine up and down.
I have since sold a steel 38T (110mm BCD 5 bolt) to a friend to use as SS on his old XTR cranks and it worked fine. No ramps or pins and a full tooth profile ensured it was fine.
I still have a full set of steel GS200 rings that I will sell if anyone is interested.
PaulD
Sorry 'Engineers' need some more coffee 😳
A friend who's taken the tech and training very seriously over the past few years with fantastic results, has actually stopped using them.
Quote
"Just recently I was talking to Dr Wind Tunnel – aka Simon Smart who is a first class engineer and seems to know loads about everything related to bicycle manufacture etc. and he suggested that I should switch back to round rings and I would notice and improvement.... which seemed odd.
Anyway I did and I have. I’ve swapped my 55T Q-Ring for a 56T Dura ace round ring and have found another 15-20Watts – at least from Sunday’s races at BBH. So I think that for riding hilly courses then elliptical rings work well but for TT’s I’m not so sure that there’s that much in it. So many of the best riders are using conventional chainrings."
He did think they might suit MTBs but hadn't tried them. I also think a lot of it will depend on your pedalling style as well
another 15-20Watts
Highly implausible. It would seem to me to be a question of feel and preference, rather than actual advantage, with maybe a slight gain in efficiency.
After all, you are only changing gear slightly, and that does not increase power.
Highly implausible. It would seem to me to be a question of feel and preference, rather than actual advantage, with maybe a slight gain in efficiency.
+1, that'll be >5% in a TT, seems unlikely.
molgrips, njee
I don't know if Nick was relating that to one specific TT but I can tell you that this [b]isn't[/b] some interweb BS willy waving.
Feel free to read his write up about his trip to the wind tunnel [url= http://www.leweswanderers.co.uk/pages/newsletters/11/03/03.pdf ]HERE[/url] and have a gander at his results [url= http://www.ctt.org.uk/Default.aspx?&gv592__gvac=2&tabid=198&gv592__gvff0=dwyer&gv592__gvfl0=12 ]HERE[/url]
In the few years he's taken TTing seriously, he's picked up local course records and consistently bangs out 30mph rides.