tag:blogger.com,1999:blog-6080071290235905056.post1937299242891933738..comments2024-02-27T18:30:46.362-08:00Comments on Blather 'bout Bikes: What's up with those funky rings...?Tom Anhalthttp://www.blogger.com/profile/08175472546482777614noreply@blogger.comBlogger26125tag:blogger.com,1999:blog-6080071290235905056.post-15299387238414890762020-09-14T13:16:25.631-07:002020-09-14T13:16:25.631-07:00I'm not quite following what your comment is i...I'm not quite following what your comment is in reference to...could you explain a bit more? Thanks.Tom Anhalthttps://www.blogger.com/profile/08175472546482777614noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-60918421992691708402020-09-14T12:18:21.117-07:002020-09-14T12:18:21.117-07:00Hi, nice to read! How about measuringing the rear-...Hi, nice to read! How about measuringing the rear-wheel? Count the rotations of the rearwheel aside the torque measured there overlayed with heart-rate? At least there should be a slight sinus on the rear-wheel-speed when using constant rpm on the crank and vice versa? Best regardsAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-70692338022516730192015-11-09T03:02:43.880-08:002015-11-09T03:02:43.880-08:00Tom,
I am interested to contact you to disscuss th...Tom,<br />I am interested to contact you to disscuss the use of non-circular chainrings for use in Functional Electrical Stimulation (FES) cycling with paralysed legs. My e-mail is:<br />vance.bergeron@ens-lyon.fr<br />Thank you for any time you might have, VanceAnonymoushttps://www.blogger.com/profile/14195050426093495489noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-4119329477162036652015-11-09T03:01:19.492-08:002015-11-09T03:01:19.492-08:00Tom,
I am interested to contact you to disscuss th...Tom,<br />I am interested to contact you to disscuss the use of non-circular chainrings for use in Functional Electrical Stimulation (FES) cycling with paralysed legs. My e-mail is:<br />vance.bergeron@ens-lyon.fr<br />Thank you for any time you might have, VanceAnonymoushttps://www.blogger.com/profile/14195050426093495489noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-80974449589449083412015-03-02T12:22:34.546-08:002015-03-02T12:22:34.546-08:00Hi Nikola,
Thanks for reading. The picture at the...Hi Nikola,<br />Thanks for reading. The picture at the top was one that was taken when I was trying different configurations of alignment to see if there were any differences. The picture, in fact, shows the position closest to the supposed "theoretical optimum" from the Malfait, et al mathematical studies linked to at the beginning of the blog post.<br /><br />As you read in the test setup above, I installed the Osymmetric ring in place of the inner ring, with a standard 54T round ring on the outside. That's obviously not what is show in the picture at the top. The Osymmetric ring was installed for "side-by-side" 54T testing as you described in your comment so that the timing of the ring curvature relative to the crankarms was as designed.<br /><br />The picture at the top just happened to be the best picture I had of the Osymmetric ring installed on the bike.<br /><br />So, in short...that picture does not invalidate anything :-)Tom Anhalthttps://www.blogger.com/profile/08175472546482777614noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-89082474677127241672015-02-25T23:10:15.990-08:002015-02-25T23:10:15.990-08:00I know this might be an old thread, however, from ...I know this might be an old thread, however, from the picture above I noticed that you installed the Osymetric chainrings the wrong way. This is a known 'issue' with cranksets with hidden bolts. The correct way to instal them is to rotate them one hole counterclockwise on the crank spider (the chaindrop protection pin doesn't line up correctly). If you made your measurements with the pictured setup all data is invalid since the Osymetric shape is not designed to work in that way. Jean-Louis Talo (inventor of Osymetric) mentions himself that he tested many shapes and setups and none came even remotely close to the current iteration. The biggest diameter of the rings should be when the cranks are at the 3/9 o'clock position (horizontal). In your picture this falls at the 1 o'clock position. Again, I am basing my comment on the picture above. I am surprised nobody noticed that up to now....Nikola Banishkihttps://www.blogger.com/profile/10400326617488773648noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-27838056383708157602013-12-25T10:25:08.982-08:002013-12-25T10:25:08.982-08:00No, as I explained above, this isn't something...No, as I explained above, this isn't something that can get calibrated out. Although the torque values will be correct, the assumption of constant rotational velocity through the pedal stroke is still violated. The folks at Quarq should understand this...I know that Jim Meyer (the founder) does.Tom Anhalthttps://www.blogger.com/profile/08175472546482777614noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-83481756890393983282013-12-25T06:00:24.760-08:002013-12-25T06:00:24.760-08:00I asked Quarq about this. I obtained a Wahoo Key a...I asked Quarq about this. I obtained a Wahoo Key and calibrated the Quarq with the Oval Chainrings on. Would this result in accurate data?Peter Maurohttps://www.blogger.com/profile/10885430979892323026noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-33536758578993291942013-12-15T11:05:45.083-08:002013-12-15T11:05:45.083-08:00I believe dorsiflexion of the foot and RPE have im...I believe dorsiflexion of the foot and RPE have implications on cycling performance. Unknownhttps://www.blogger.com/profile/17060046735787957102noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-86512046668517869782013-04-26T02:12:29.683-07:002013-04-26T02:12:29.683-07:00interesting blog. It would be great if you can pro...interesting blog. It would be great if you can provide more details about it. Thank you...<br /><br /><br /><a href="http://bestandards.com" rel="nofollow"> <br />Torque Calibration</a><br />calibrationhttps://www.blogger.com/profile/02551365131469569816noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-30372477142092122162013-02-16T14:29:02.381-08:002013-02-16T14:29:02.381-08:00Well...you can probably guess the content of any f...Well...you can probably guess the content of any future blog post on the subject from my replies above ;-)<br /><br />Good point on adding the subscription link thingy...I just did that (at least I think I did). I'm new to all this blog stuff....Tom Anhalthttps://www.blogger.com/profile/08175472546482777614noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-23881404524610545092013-02-16T10:34:29.621-08:002013-02-16T10:34:29.621-08:00"on the question of whether or not non-round ..."on the question of whether or not non-round rings have the potential to actually increase pedaling power output...well, I have my opinions on that, but I'll leave that for another blog post...."<br /><br />Such a tease... Can you at least add a follow or subscription link to the blog so we can keep updated? <br /><br />Thomas Gerlachhttps://www.blogger.com/profile/02201737621337374644noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-11827320453067520042013-02-10T14:01:15.445-08:002013-02-10T14:01:15.445-08:00Actually...I think that the proper way of looking ...Actually...I think that the proper way of looking at it is that even if it is possible that non-round rings may be "optimal", it's going to happen under limited conditions of orientation with respect to the rider...therefore, round rings may be the best compromise all around.<br /><br />One thing to remember is that key assumption of non-round rings is that it's possible to change the muscle shortening velocities and joint angle velocities in the upper leg (where the driving muscles are) by varying the crank rotational speed. That assumption relies on the extra degrees of freedom in the lower leg not changing when changing ring shapes. Kinematic data suggests that's not the case.<br /><br />Our bodies are REALLY good at figuring out how to operate in their preferred manner (i.e. muscle shortening speeds, etc.) and understanding that there's more potential for changing the upper leg joint velocities and muscle shortening speeds just by flexing of the ankle than is possible with any reasonable chainring ovality give rise to questions about non-round ring effectivity. My suspicion is that's basically what the whole "accomodation" is all about...it's your body "figuring out" how to keep using those upper leg muscles in the way it prefers...thereby effectively defeating the whole point.Tom Anhalthttps://www.blogger.com/profile/08175472546482777614noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-68394603619486837902013-02-10T07:22:11.956-08:002013-02-10T07:22:11.956-08:00I have thought about the oval chain ring debate a ...I have thought about the oval chain ring debate a bit. It seems like definitive proof of improved performance would be very difficult. The one thought I have is to look at the problem from the reverse perspective. Saying oval rings can't improve performance is equivalent to saying that round rings are optimal. <br /><br />One idea I mull over is what would happen if you shifted the orientation of the oval ring by 90 degrees. This would slow the velocity of the foot at the top of the pedal stroke and speed it up as you go through the "power portion" of the pedal stroke. I can also imagine some very radically shaped chain rings that would be nearly impossible to go fast on (big rectangle)<br /><br />Me thinks that chain rings may be like seats. There is a shape that would be optimal, but it depends on the individual.michaelhttps://www.blogger.com/profile/07314532671682790869noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-90916636602905618702013-02-09T16:52:43.693-08:002013-02-09T16:52:43.693-08:00My only thoughts are that HR is only a response to...My only thoughts are that HR is only a response to your effort (amongst a myriad of other things) and there's a LOT of variability in that response.<br /><br />This is the reason why on board power meters were developed...otherwise, why bother with the expense? Just buy a HR monitor. They're much cheaper.<br /><br />I guess I'm just questioning the ability to be able to determine if that 3bpm difference in the intercept you see is "real" or not...Besides, let's say that the rings DO drop your HR for a given effort. Does your ability to do that effort (i.e. power vs. duration) change? If not, big deal.Tom Anhalthttps://www.blogger.com/profile/08175472546482777614noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-77692788734067117062013-02-09T14:08:05.250-08:002013-02-09T14:08:05.250-08:00I did some trainer testing and recorded HR vs rear...I did some trainer testing and recorded HR vs rear wheel speed on a graded power/speed test (I.e., increase speed every 2 minutes until my HR hit 180). I would switch back and forth between rings. My slope of the fitted HRvs.speed graph was no statistically sigificant, but the intercept indicated a 3 bpm lower heart rate for the rotor ring. Any thoughts on the validity of this testing method?michaelhttps://www.blogger.com/profile/07314532671682790869noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-24495494744972643432013-01-16T17:42:10.558-08:002013-01-16T17:42:10.558-08:00I tried them for a week with no noticeable differe...I tried them for a week with no noticeable difference in Powertap reported power output even considering my lack of one ankle to flex. It wasn't a formal test and plenty of other variables in the mix so nothing I can hang my hat on but honestly I didn't notice any difference when pedalling. Lost in the noise.Alex Simmonshttps://www.blogger.com/profile/00698332397074026424noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-92056941579588600492013-01-13T07:39:08.865-08:002013-01-13T07:39:08.865-08:00Info,
That's a subject for another blog post ;...Info,<br />That's a subject for another blog post ;-)...but, for now, I'll just say that the "theory" of non-round rings is predicated on them being able to change the joint velocity and muscle shortening speeds in the upper leg, and yet you have vastly more capability of doing so just by flexing your ankle joint than can be accomplished with any reasonable ring ovality. Think about that for a bit...<br /><br />Oh, and placebo is a pretty powerful thing. Otherwise, it wouldn't need to be controlled for in studies, right?Tom Anhalthttps://www.blogger.com/profile/08175472546482777614noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-82219240215616381012013-01-13T06:20:47.541-08:002013-01-13T06:20:47.541-08:00what is your opinion when people claim more than ...what is your opinion when people claim more than 4% power improvement do you think that is real powerimprovement or not ? infohttps://www.blogger.com/profile/06595709381446513426noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-31960108868262113152013-01-12T18:49:14.553-08:002013-01-12T18:49:14.553-08:00Do you mean the "optimum" position from ...Do you mean the "optimum" position from that mathematical study? If so, yes. The inflation was still present. Didn't notice any real power gains either.Tom Anhalthttps://www.blogger.com/profile/08175472546482777614noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-48912061473303002842013-01-12T17:53:32.675-08:002013-01-12T17:53:32.675-08:00Tom did you try the osymetric with the modified po...Tom did you try the osymetric with the modified position? Just checking as it is very similar to my experience almost no change as measured on my powertap. DallasTriNerdhttps://www.blogger.com/profile/09736331828918727282noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-84967167686568890022013-01-12T13:10:40.005-08:002013-01-12T13:10:40.005-08:00Correction, I linked to that thread above under &q...Correction, I linked to that thread above under "user reports".Tom Anhalthttps://www.blogger.com/profile/08175472546482777614noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-49905716200606083572013-01-12T13:07:15.821-08:002013-01-12T13:07:15.821-08:00I'm pretty sure that the Dan Connelly blog pos...I'm pretty sure that the Dan Connelly blog post I linked to also links to that very same wattage list thread.<br /><br />Robert, yes.<br /><br />Alex, thanks!Tom Anhalthttps://www.blogger.com/profile/08175472546482777614noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-48227213459399525632013-01-12T12:50:03.924-08:002013-01-12T12:50:03.924-08:00Speculated since 2006: https://groups.google.com/f...Speculated since 2006: https://groups.google.com/forum/#!msg/wattage/5prBUKY20s0/npZID_tb-5AJAndrew R. Coggan, Ph.D.https://www.blogger.com/profile/07152375621226680227noreply@blogger.comtag:blogger.com,1999:blog-6080071290235905056.post-64296218156288616342013-01-12T12:45:30.755-08:002013-01-12T12:45:30.755-08:00Nice work Tom.Nice work Tom.Alex Simmonshttps://www.blogger.com/profile/10881438594014875713noreply@blogger.com