hi
james I have designed a chainring to the specifications you asked for, pm me to see where we go from there.
kendrick
eliptical chainring - want to try one?
Re: eliptical chainring - want to try one?
Here's a zip with some dxfs:
ellipt36 is a 36 tooth elliptical to go on a 110PCD 5 bolt spider. It goes with he 48 tooth
ellipt48chainring is the 48 tooth one that started the thread (still not been run for real - I'll drop a line when it is)
osymm34chinring is a 34 tooth osymmetric style ring to go on a 104PCD 4 bolt spider - just to check out the design process ;^)
ellipt36 is a 36 tooth elliptical to go on a 110PCD 5 bolt spider. It goes with he 48 tooth
ellipt48chainring is the 48 tooth one that started the thread (still not been run for real - I'll drop a line when it is)
osymm34chinring is a 34 tooth osymmetric style ring to go on a 104PCD 4 bolt spider - just to check out the design process ;^)
- Attachments
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[The extension zip has been deactivated and can no longer be displayed.]
Re: eliptical chainring - want to try one?
As promised - the oval ring is now being pedalled on my brother's bike. Early impressions are favourable, powerful 'feel' to it. I think it will take a little while to get used to & both John and I are interested in how his slightly suspect knee reacts over 100 miles or so. Having had another go I noticed the higher speed through top and bottom centre (which I didn't notice before), I guess you notice it when your cadence goes up - and wonder whether that is good or bad for the joints.
Anyway - not dismissed out of hand as a pointless gimmick;- not yet anyway ;^)
Anyway - not dismissed out of hand as a pointless gimmick;- not yet anyway ;^)
Re: eliptical chainring - want to try one?
Well done for following through and thinking for yourself instead of blindly following what the 'experts' say.
You shouldn't notice any beneficial effect on your knees whilst using an ellipsoid chainring ~ until you return to circular ones; it's only then you realise how good these are for wonky knees.
After about six years of using only ellipsoids, last summer I rode a bike with circular rings.
Never again, is all I can say!
You shouldn't notice any beneficial effect on your knees whilst using an ellipsoid chainring ~ until you return to circular ones; it's only then you realise how good these are for wonky knees.
After about six years of using only ellipsoids, last summer I rode a bike with circular rings.
Never again, is all I can say!
Re: eliptical chainring - want to try one?
the pedant in me is forced to mention that an 'ellipsoid' is by definition a three-dimensional form, where an 'ellipse' is a two-dimensional form. Chainrings based on an ellipse are therefore strictly 'elliptical' not 'ellipsoid' in the same way that round chainrings are circular, not spherical.
Re the 'is it worth it' question; if it feels more comfortable to ride an elliptical chainring (in whichever orientation happens to suit you), why not? The sceptic in me thinks that few studies have shown any demonstrable improvement, and few of these have been published in detail. In any event devising a test where the effects of habituation (in either direction) are eliminated is virtually impossible.
I note also that people 'work differently' to one another. Something to do with inherent musculature (and training) no doubt. I note also that much training seems to help the rider 'pedal in better circles' when under duress. If there is a (default) non-circular pedalling action that people lapse into when not making nice circles, having chainrings that shape may be of benefit.
cheers
Re the 'is it worth it' question; if it feels more comfortable to ride an elliptical chainring (in whichever orientation happens to suit you), why not? The sceptic in me thinks that few studies have shown any demonstrable improvement, and few of these have been published in detail. In any event devising a test where the effects of habituation (in either direction) are eliminated is virtually impossible.
I note also that people 'work differently' to one another. Something to do with inherent musculature (and training) no doubt. I note also that much training seems to help the rider 'pedal in better circles' when under duress. If there is a (default) non-circular pedalling action that people lapse into when not making nice circles, having chainrings that shape may be of benefit.
cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
-
NATURAL ANKLING
- Posts: 13779
- Joined: 24 Oct 2012, 10:43pm
- Location: English Riviera
Re: eliptical chainring - want to try one?
Hi,
Whilst I agree with most of what you say, I am still at a loss of what "nice circles" are
I suppose that if it was to feel good and smooth, plus pain free, this is what it means.
When you consider that through habituation / training with no change in effort or any intentual change in style, this auto cycle of complex movements and muscle timing is supposeidly controlled by the nervous system, not the brain, it will feel to rider just like that.
I wonder that if you fitted chain guards to identical bikes with two very different shaped chain wheels, and asked two riders to ride them for considerable length of time maybe weeks or months, hiding there effects slightly with some type of damper in early days.
What would be their feelings after such test
Below is some images which might not be visible to all readers.
Cheers,
Brucey wrote:the pedant in me is forced to mention that an 'ellipsoid' is by definition a three-dimensional form, where an 'ellipse' is a two-dimensional form. Chainrings based on an ellipse are therefore strictly 'elliptical' not 'ellipsoid' in the same way that round chainrings are circular, not spherical.
Re the 'is it worth it' question; if it feels more comfortable to ride an elliptical chainring (in whichever orientation happens to suit you), why not? The sceptic in me thinks that few studies have shown any demonstrable improvement, and few of these have been published in detail. In any event devising a test where the effects of habituation (in either direction) are eliminated is virtually impossible.
I note also that people 'work differently' to one another. Something to do with inherent musculature (and training) no doubt. I note also that much training seems to help the rider 'pedal in better circles' when under duress. If there is a (default) non-circular pedalling action that people lapse into when not making nice circles, having chainrings that shape may be of benefit.
cheers
Whilst I agree with most of what you say, I am still at a loss of what "nice circles" are
I suppose that if it was to feel good and smooth, plus pain free, this is what it means.
When you consider that through habituation / training with no change in effort or any intentual change in style, this auto cycle of complex movements and muscle timing is supposeidly controlled by the nervous system, not the brain, it will feel to rider just like that.
I wonder that if you fitted chain guards to identical bikes with two very different shaped chain wheels, and asked two riders to ride them for considerable length of time maybe weeks or months, hiding there effects slightly with some type of damper in early days.
What would be their feelings after such test
Below is some images which might not be visible to all readers.
Cheers,
NA Thinks Just End 2 End Return + Bivvy - Some day Soon I hope
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.
Re: eliptical chainring - want to try one?
To me, "nice circles" mean that you are spinning with (what feels like) a continual forward pressure on each crank, and with smooth variations in that pressure.
I've been using Rotor Q-rings on my road bike for the last year or so. I found the most noticeable difference to the pedalling action is when climbing out of the saddle. It feels more powerful and less jerky, presumably because I'm spending less time struggling through tdc. Put another way, rather than "landing hard" on the bottom of each pedal stroke, it feels as though I'm smoothly transitioning into the next. I've also found that my endurance has improved, though it's hard to isolate that from other causes (more training, different bike).
I've been using Rotor Q-rings on my road bike for the last year or so. I found the most noticeable difference to the pedalling action is when climbing out of the saddle. It feels more powerful and less jerky, presumably because I'm spending less time struggling through tdc. Put another way, rather than "landing hard" on the bottom of each pedal stroke, it feels as though I'm smoothly transitioning into the next. I've also found that my endurance has improved, though it's hard to isolate that from other causes (more training, different bike).
Last edited by rfryer on 26 Apr 2013, 10:45am, edited 1 time in total.
Re: eliptical chainring - want to try one?
'Nice circles' would be ones where you are not pedalling in an uncoordinated fashion.
Even with as many miles/years under my wheels I still catch myself pedalling badly at times.
Typically when I'm climbing up a long climb and suffering a bit, I suddenly think 'blimey, what kind of numpty is pushing these pedals round?' and just by concentrating harder on the quality of my pedalling action, I might speed up for no increase in effort. Clearly I'm not completely habituated to pedalling in nice circles all the time, and when I'm a bit knackered I tend to do something else that is not so good.
Greg Lemond used to talk about his pedalling action, famously describing it as 'like scraping dog dirt off your shoes'; clearly even he still had to think about it at least some of the time.
Some sportsmen have a very strong view on training methods because of the (potentially adverse) effect it can have on habituation; the famous golfer, Ben Hogan, would never play 'casual golf' or indeed even hit casual shots, ever; his argument was that he wished to practice and ingrain only the best technique, not some casual approximation to it. Some top-class cyclists take the same view, and never turn a pedal unless it is accompanied by good technique and high levels of concentration, as part of a structured training programme, or a race.
Ellliptical chainrings might well produce a more 'natural' pedalling action for some people, but this may not be true for all, and may still be subservient to the effects of habituation in well-trained riders.
cheers
Even with as many miles/years under my wheels I still catch myself pedalling badly at times.
Typically when I'm climbing up a long climb and suffering a bit, I suddenly think 'blimey, what kind of numpty is pushing these pedals round?' and just by concentrating harder on the quality of my pedalling action, I might speed up for no increase in effort. Clearly I'm not completely habituated to pedalling in nice circles all the time, and when I'm a bit knackered I tend to do something else that is not so good.
Greg Lemond used to talk about his pedalling action, famously describing it as 'like scraping dog dirt off your shoes'; clearly even he still had to think about it at least some of the time.
Some sportsmen have a very strong view on training methods because of the (potentially adverse) effect it can have on habituation; the famous golfer, Ben Hogan, would never play 'casual golf' or indeed even hit casual shots, ever; his argument was that he wished to practice and ingrain only the best technique, not some casual approximation to it. Some top-class cyclists take the same view, and never turn a pedal unless it is accompanied by good technique and high levels of concentration, as part of a structured training programme, or a race.
Ellliptical chainrings might well produce a more 'natural' pedalling action for some people, but this may not be true for all, and may still be subservient to the effects of habituation in well-trained riders.
cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
Re: eliptical chainring - want to try one?
Indeed ~ pedalling technique is something that can be reviewed from time to time, and during a climb is probably the best occasion.
It is important to mention here that elliptical chainrings, particularly the more extreme ovals, are very useful for slow-cadence work; I have no interest in speed when cycling, but that doesn't mean I'm not interested in efficiency.
Despite many years of using elliptical chainrings, because they make it easier to push a higher gear, I find myself doing so and then deliberately drop down a gear, which then feels much better.
This effect can lead to someone not used to their efficiency to try pushing a higher ratio, which gives the impression of sluggishness.
Whatever the practical/personal effects, the mechanical logic of the increased efficiency cannot be denied.
It is important to mention here that elliptical chainrings, particularly the more extreme ovals, are very useful for slow-cadence work; I have no interest in speed when cycling, but that doesn't mean I'm not interested in efficiency.
Despite many years of using elliptical chainrings, because they make it easier to push a higher gear, I find myself doing so and then deliberately drop down a gear, which then feels much better.
This effect can lead to someone not used to their efficiency to try pushing a higher ratio, which gives the impression of sluggishness.
Whatever the practical/personal effects, the mechanical logic of the increased efficiency cannot be denied.
-
NATURAL ANKLING
- Posts: 13779
- Joined: 24 Oct 2012, 10:43pm
- Location: English Riviera
Re: eliptical chainring - want to try one?
Hi,
I found today in training on turbo whatever, I was trying to catch up on being off for three weeks earlier in the year.
So I started fast and faded at the end like you do, to compensate for the sore quads I resorted to using the hams more which to be honest I only normally do finishing a hill when I have over done it earlier in ride. And normally I would drop the heels for ten seconds and then point the toes for another ten.
But today I found it quite easy to just swap the emphasis from nuetral to hams then back to quads, in some vain attempt for less stress on flagging muscles.
I did not change my foot position to my lower leg in doing this and it felt very natural.
When cyling with some comfort at an semi endurance pace it tends to me to all blend in to one action, probably from the little power you are expending, it is more difficult to isolate muscles with just feel. Sort of flywheel effect, though I dont like that saying, I would strongly prefer it if you were to start using "Tapping out" the rythym
When you consider training which could lead to habitual, or vise versa, muscle dynamics,biomechanics, body to crank mechanics, and add your own conscious muscle control, along with your minds interpretation.
Below is a diagram of the path of the ball of foot, though not 100 % true is very representative.
Delleted for edit
Cheers,
Edited Good spot I am well off line there, I appoligise.............rethink....rethink..................
I found today in training on turbo whatever, I was trying to catch up on being off for three weeks earlier in the year.
So I started fast and faded at the end like you do, to compensate for the sore quads I resorted to using the hams more which to be honest I only normally do finishing a hill when I have over done it earlier in ride. And normally I would drop the heels for ten seconds and then point the toes for another ten.
But today I found it quite easy to just swap the emphasis from nuetral to hams then back to quads, in some vain attempt for less stress on flagging muscles.
I did not change my foot position to my lower leg in doing this and it felt very natural.
When cyling with some comfort at an semi endurance pace it tends to me to all blend in to one action, probably from the little power you are expending, it is more difficult to isolate muscles with just feel. Sort of flywheel effect, though I dont like that saying, I would strongly prefer it if you were to start using "Tapping out" the rythym
When you consider training which could lead to habitual, or vise versa, muscle dynamics,biomechanics, body to crank mechanics, and add your own conscious muscle control, along with your minds interpretation.
Below is a diagram of the path of the ball of foot, though not 100 % true is very representative.
Delleted for edit
Cheers,
Edited Good spot I am well off line there, I appoligise.............rethink....rethink..................
Last edited by NATURAL ANKLING on 26 Apr 2013, 1:32pm, edited 2 times in total.
NA Thinks Just End 2 End Return + Bivvy - Some day Soon I hope
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.
You'll Still Find Me At The Top Of A Hill
Please forgive the poor Grammar I blame it on my mobile and phat thinkers.
Re: eliptical chainring - want to try one?
Surely some mistake - you don't get the ball of your foot underneath the pedal, do you? 
Re: eliptical chainring - want to try one?
I bought a Claude Butler Super Dalesman in 1988.
It was the 531 bees knees and the first really decent bike I ever had.
Shimano Biopace fitted as standard.
I never could understand why Biopace was a good idea.
But I still have four 531 framed bikes on the go.
It was the 531 bees knees and the first really decent bike I ever had.
Shimano Biopace fitted as standard.
I never could understand why Biopace was a good idea.
But I still have four 531 framed bikes on the go.
Re: eliptical chainring - want to try one?
BioPace was a very bad idea, a completely stupid waste of time.
Re: eliptical chainring - want to try one?
Just to add another dimension to this discussion, you may have noticed that the pattern of spider boltholes on my chainrings were designed to give maximum adjustability of the angle of the major axis of the elipse.
In real life I stuck it on at 110degrees lag from the crank & it's not moved - John seems more than happy with it there, (still)
A convenient angle reference is 108degrees lag - a 5 bolt spider has one bolt opposite the crank so the next one is 72degrees on from there, i.e 108degrees lag. AN elliptic ring with 108degrees lag would have one of its 5 boltholes ON ITS MAJOR AXIS.
Anybody have any thoughts about optimum angle? (apart from Mr Biopace ;^) (OK including him....) The 110 degree thing gives minimum gearing through the deadspot & seems logical to me, also seems to line up maximum gearing with maximum available pedal force pretty well - but I know some folk have other theories........ (at the start of the thread a couple of posters suggested I rotate it up to 60 degrees)
On an unrelated note - I'm sort of concluding that the oval ring can't increase power output (and therefore speed) as that is aerobically limited, but it could widen the "sweet spot" range of cadences & maybe make putting a surge of effort in more comfortable & easier on the legs. IN other words I suspect it might give a benefit in theose areas that are impossible to measure..... My brother seems to like it & is sticking with it for now.
Oh and another thing - how elliptical should it be? I suspect I may have slightly over-egged the pudding with the original design (fair enough to my mind as it was just a test item - so make it extreme) - what ratio between major and minor radii do people think would be appropriate - I'm guessing Brucey's vote would be 1:1 ;^)
In real life I stuck it on at 110degrees lag from the crank & it's not moved - John seems more than happy with it there, (still)
A convenient angle reference is 108degrees lag - a 5 bolt spider has one bolt opposite the crank so the next one is 72degrees on from there, i.e 108degrees lag. AN elliptic ring with 108degrees lag would have one of its 5 boltholes ON ITS MAJOR AXIS.
Anybody have any thoughts about optimum angle? (apart from Mr Biopace ;^) (OK including him....) The 110 degree thing gives minimum gearing through the deadspot & seems logical to me, also seems to line up maximum gearing with maximum available pedal force pretty well - but I know some folk have other theories........ (at the start of the thread a couple of posters suggested I rotate it up to 60 degrees)
On an unrelated note - I'm sort of concluding that the oval ring can't increase power output (and therefore speed) as that is aerobically limited, but it could widen the "sweet spot" range of cadences & maybe make putting a surge of effort in more comfortable & easier on the legs. IN other words I suspect it might give a benefit in theose areas that are impossible to measure..... My brother seems to like it & is sticking with it for now.
Oh and another thing - how elliptical should it be? I suspect I may have slightly over-egged the pudding with the original design (fair enough to my mind as it was just a test item - so make it extreme) - what ratio between major and minor radii do people think would be appropriate - I'm guessing Brucey's vote would be 1:1 ;^)
Re: eliptical chainring - want to try one?
Yep, Bob, you're right ~ one of the few who 'get it'.
I guess what you call lag, I call 'retardation', and it all depends on where your datum is, and I can't figure out where your's is. To keep things simple: crank vertical pointing up, major axis 2/8 o'clock, minor axis 5/11 o'clock.
"Do they make you go faster?" is the a question I have to answer quite often. When I answer elliptical rings have benefits more valuable than increased speed, cyclists rarely understand, as if there is only one important aim in cycling; to go as fast as possible. Curiously, non-cyclists usually fully understand the concept immediately.
As to the degree of 'ovality'; for high-cadence riding you want a less elliptical ring, and for low-cadence pedalling, a more elliptical ring.
bobc wrote:Just to add another dimension to this discussion, you may have noticed that the pattern of spider boltholes on my chainrings were designed to give maximum adjustability of the angle of the major axis of the elipse.
In real life I stuck it on at 110degrees lag from the crank & it's not moved - John seems more than happy with it there, (still)
A convenient angle reference is 108degrees lag - a 5 bolt spider has one bolt opposite the crank so the next one is 72degrees on from there, i.e 108degrees lag. AN elliptic ring with 108degrees lag would have one of its 5 boltholes ON ITS MAJOR AXIS.
Anybody have any thoughts about optimum angle? (apart from Mr Biopace ;^) (OK including him....) The 110 degree thing gives minimum gearing through the deadspot & seems logical to me, also seems to line up maximum gearing with maximum available pedal force pretty well - but I know some folk have other theories........ (at the start of the thread a couple of posters suggested I rotate it up to 60 degrees)
I guess what you call lag, I call 'retardation', and it all depends on where your datum is, and I can't figure out where your's is. To keep things simple: crank vertical pointing up, major axis 2/8 o'clock, minor axis 5/11 o'clock.
"Do they make you go faster?" is the a question I have to answer quite often. When I answer elliptical rings have benefits more valuable than increased speed, cyclists rarely understand, as if there is only one important aim in cycling; to go as fast as possible. Curiously, non-cyclists usually fully understand the concept immediately.
As to the degree of 'ovality'; for high-cadence riding you want a less elliptical ring, and for low-cadence pedalling, a more elliptical ring.