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Research on Feedback Sports Omnium Portable Track Trainer (rollers)

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Research on Feedback Sports Omnium Portable Track Trainer (rollers)

Old 12-29-17, 12:07 PM
  #51  
rfreese888
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Originally Posted by rensho3 View Post
Is your problem that the rollers don't provide enough resistance. If so, then check and see if you have the track version. If you problem is that the rollers provide enough resistance, but you have to "mash" a big gear to get the sensor to see enough speed to give you a faux power, then I suspect that the rollers have not "seized up", which would provide a lot of resistance at very low speeds. If you can be more precise in the effect you are noticing, and the parameters that produce it, we may be able to help you figure this one out.
Itís more the latter, too much resistance and unable to generate enough speed to get virtual power up to normal level. Rollers are not seized up in that they do spin, but takes way too much effort to spin them.
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Old 12-29-17, 07:28 PM
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Originally Posted by krispenhartung View Post
Hi all,
It gets more interesting. So apparently, Feedback Sports says that you can remove one of the two back drums in their standard Omnium progressive resistance trainers, flip it 180 degrees, and it will stop functioning as a progressive resistance roller. This would effectively reduce the resistance by roughly half. I still want my progressive rollers for my road and TT bikes, so I'm toying around with the idea of putting just one progressive resistance roller on the Omnium Track trainer, and seeing if that gets me the resistance I need. I predict it will get my warm up watts to about 160-200 at higher cadences, which is exactly what I after.
Did you end up trying this? How did it work out? I've been putting off ordering an omnium trainer because I really can't decide if I should go with the track version or regular. The idea of something adjustable and in between the two extremes sounds very appealing to me.
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Old 12-29-17, 09:16 PM
  #53  
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Originally Posted by MarkWW View Post
Did you end up trying this? How did it work out? I've been putting off ordering an omnium trainer because I really can't decide if I should go with the track version or regular. The idea of something adjustable and in between the two extremes sounds very appealing to me.
I have a new sled on the way with the progressive rollers on it, and I plan on performing the swaperoo on that one. I like the idea of having three possible power combinations. Anyway, when it gets here (should be any day) I will invert one drum, attach it to my Omnium track and give it a try. Would you like me to conduct any tests? My plan was to ride on both drum options at 90, 100, 100, 115, 120, 130, and 140 RPM and record the average watts for each. I'll also do the test on two bikes, my Fuji Track Elite with the tubulars at 150psi, and my BMC Trackmachine at 115 psi.

This should give a good depiction of what just one progressive resistance drum will produce in terms of a non-linear wattage increase with increased RPMs.
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Old 12-30-17, 07:52 PM
  #54  
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Originally Posted by krispenhartung View Post
My plan was to ride on both drum options at 90, 100, 100, 115, 120, 130, and 140 RPM and record the average watts for each. I'll also do the test on two bikes, my Fuji Track Elite with the tubulars at 150psi, and my BMC Trackmachine at 115 psi.
Definitely note the gearing and speed as well. Hereís the resistance curve of the original SportCrafters trainer. Donít know if theyíre still making the drums or if Feedback took over that.


Source: http://www.slowtwitch.com/Products/SportCrafters_Omnium_trainer_4123.html
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Old 12-30-17, 09:27 PM
  #55  
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Originally Posted by Hrothgar42 View Post
Definitely note the gearing and speed as well. Hereís the resistance curve of the original SportCrafters trainer. Donít know if theyíre still making the drums or if Feedback took over that.


Source: SportCrafters Omnium trainer - Slowtwitch.com
Will do. I plan on creating a custom workout for my Wahoo Elmnt Bolt so I can go back and look at the data for each interval.
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Old 01-01-18, 04:31 PM
  #56  
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Originally Posted by rfreese888 View Post
Itís more the latter, too much resistance and unable to generate enough speed to get virtual power up to normal level. Rollers are not seized up in that they do spin, but takes way too much effort to spin them.
Having contacted the product engineer in Feedback Sports and Trainer Road Support - I understand more now the difference in power curves between my Cycleops Fluid 2 and the Feedback Omnium. Essentially the Fluid 2 has a much more [wait for it] fluid curve and you get more virtual watts per kmh of wheel speed, whereas the Omnium has a flatter curve and fewer virtual watts per kmh.

When I did a sub threshold workout on the Omnium yesterday holding around 85-90% of my lactate threshold heart rate (145 bpm), I was getting around 100 watts of virtual power. This is practically inverse to what I get on the Fluid 2 where 141 bpm will get me around 225 watts of virtual power.

I am not an engineer but I wish the training software could account for these differences so virtual power would be the same regardless of which trainer I am on, AND they would all match a power meter being run in parallel.

Moral of the story is I need a proper power meter to know what my actual power is. I am thinking Powertap Pedals to take with me with my Omnium when I am not on the Fluid 2 at home.
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Old 01-02-18, 06:35 AM
  #57  
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Originally Posted by rfreese888 View Post
Having contacted the product engineer in Feedback Sports and Trainer Road Support - I understand more now the difference in power curves between my Cycleops Fluid 2 and the Feedback Omnium. Essentially the Fluid 2 has a much more [wait for it] fluid curve and you get more virtual watts per kmh of wheel speed, whereas the Omnium has a flatter curve and fewer virtual watts per kmh.

When I did a sub threshold workout on the Omnium yesterday holding around 85-90% of my lactate threshold heart rate (145 bpm), I was getting around 100 watts of virtual power. This is practically inverse to what I get on the Fluid 2 where 141 bpm will get me around 225 watts of virtual power.

I am not an engineer but I wish the training software could account for these differences so virtual power would be the same regardless of which trainer I am on, AND they would all match a power meter being run in parallel.

Moral of the story is I need a proper power meter to know what my actual power is. I am thinking Powertap Pedals to take with me with my Omnium when I am not on the Fluid 2 at home.
You have discovered the difference between a Fluid and a Magnetic trainer.

Also, all of those "X Speed = Y Power" charts should be taken with a whole shaker of salt. I'm pretty sure they were all very begrudgingly created by engineers under the orders of someone in the marketing department.
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Old 01-02-18, 07:38 AM
  #58  
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For training with track bikes on trainers, the very best option is to use a mag trainer. That way you can coordinate your torque (resistance) and cadence to whatever tune you like. Not coincidentally, Torque x Cadence = Power.

For warmup and cool down only, rollers are a convenient option at the velodrome because one doesn't have to latch the wheel into the device. Just hop on and off with the bike.

Once you add a fork stand to rollers that have magnetic resistance, you don't create the best of both worlds...you create the worst of both worlds.

You can't get the same resistance as you can with a standard mag trainer. You don't have the convenience of rollers.

If you are going to sacrifice convenience and affix the bike to a trainer and you require significant variable resistance, go with a proper mag trainer. That is your best option when using a track bike.

Buying a $1,000 set of Powertap pedals won't solve this. A $75 mag trainer will.
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Old 01-02-18, 09:21 AM
  #59  
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Originally Posted by rfreese888 View Post
Having contacted the product engineer in Feedback Sports and Trainer Road Support - I understand more now the difference in power curves between my Cycleops Fluid 2 and the Feedback Omnium. Essentially the Fluid 2 has a much more [wait for it] fluid curve and you get more virtual watts per kmh of wheel speed, whereas the Omnium has a flatter curve and fewer virtual watts per kmh.

When I did a sub threshold workout on the Omnium yesterday holding around 85-90% of my lactate threshold heart rate (145 bpm), I was getting around 100 watts of virtual power. This is practically inverse to what I get on the Fluid 2 where 141 bpm will get me around 225 watts of virtual power.

I am not an engineer but I wish the training software could account for these differences so virtual power would be the same regardless of which trainer I am on, AND they would all match a power meter being run in parallel.

Moral of the story is I need a proper power meter to know what my actual power is. I am thinking Powertap Pedals to take with me with my Omnium when I am not on the Fluid 2 at home.
I just did a little reading into this, and it sounds like both trainers should be supported. When you switched between your fluid trainer and the feedback, did you change the settings in trainnerroad to use the different power curve? It sounds like virtual power might still be using your fluid trainer power curve. https://support.trainerroad.com/hc/en-us/articles/201655670-Setup-and-Tips
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Old 01-02-18, 10:17 AM
  #60  
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So, I'm on the TrainerRoad website and...wow...talk about pseudoscience.

I've owned make 12-15 different trainers and rollers over the years. Most were top name brands with which we are all familiar. I've also used 3 different track SRM units, 1 road PowerTap, and 3 different CycleOps spin bikes with Power Meters attached.

There is no dang way that this product does what they say it does.

One quick way to refute this: If you look at a basic mag trainer (that they support), it's actuated by a simple cable that is similar to a derailleur cable. This moves the magnetic unit closer or further away providing more or less resistance. They literally provide a chart stating that click #1 provides this power curve and click #2 provides that power curve. If you examine the mag trainer, you'll see how much adjustment range is in play. It's nowhere near being precise. Not to mention tire pressure or how tight you press the resistance unit up against the tire which deforms it.



What happens when your adjuster barrel is twisted more or less??

Save your money.

You'll be better off working off of RPE or Heart Rate. Seriously...avoid this product if numbers are important to you at all.

If you will pay them to give you power readings, hell, send me $5/workout and I'll mail you a piece of paper with a custom hand-drawn chart of what your power readings were for that workout


EDIT:
It seems that this company (as with many others) are capitalizing on the phrase "Power Meter" in order to make money. "Everybody uses power meters." + "Everybody says I need a power meter." = Being taken advantage of by companies.

EDIT 2:
Because the "science" behind their charts is so loosey-goosey, there is no reliable way to compare data from Trainer A to Trainer B reliably. The best one can do is simply relate things to the same trainer. "I did this effort on click 2 of my ABC trainer for this long..."

Last edited by carleton; 01-02-18 at 10:25 AM.
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Old 01-02-18, 04:00 PM
  #61  
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Hey Carleton!

We appreciate your feedback upon reading through our site and I am hoping to clarify a few key points.

Firstly, we totally agree that VirtualPower is not as dependable or accurate as a real power meter. We highly recommend that our users aquire a strain guage power meter if it is within their means. However, as we all know, cycling is already an expensive sport and not everyone has $650+ to spend on a quality power meter.

And this is why we created VirtualPower. While certainly not perfect, it is much better than RPE and Heart Rate for a few reasons. Heart Rate is a lagging indicator, that takes about 30-45 seconds to adjust to a change in effort. On top of that issue, heart rate is effected by a huge range of variables, specifically fatigue, sleep, stress, illness, glycogen level, hydration level, temperature, humidity, motivation, and caffeine consumption. RPE has its own shortcomings, specifically the fact that as you fatigue, the same level of power may seem significanly more painful. If you do not have an objective way to measure your output, you will slowly lower your power level if you are only basing your efforts based on RPE.

This is where VirtualPower comes in. In regards to the Power Curve graph, this curve actually comes straight from the manufacturer. They measure the resistance on one of their units and, upon request, they have shared the results with us. That being said. we make no claims to be able to perfectly and accurately estimate your FTP. There are a few factors that can swew your numbers one way or the other, but the important thing is that they as long as your setup is the same from day to day, you will have a consistent VirtualPower number to depend on. Consistency and precision are the most important variables when training indoors. Even if your VirtualPower readings are not 100% representative of your outdoor power, you can still reap the benefits of training with power as long as you use the same trainer and VirtualPower curve for each workout. Doing so means your results will be comparable, and you'll be able to track your progress.

In regards to EDIT 2, you are absolutely correct. You cannot compare VirtualPower from Trainer A to the VirtualPower from Trainer B since VirtualPower is not a perfect objective representation of your power.

I hope this can clear things up a little bit. We are extremely dedicated to avoiding pseudoscience and we only implement features that we genuinely believe will make our subscribers faster cyclists.

Feel free to reach out if you ever have any more questions or comments.

Cheers,
Bryce Lewis
TrainerRoad Community Manager
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Old 01-02-18, 04:46 PM
  #62  
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Thanks for the comments, Bryce!

What do you say about the inconsistencies of resistance of mag trainers based on the cable? If the cable is stretched or not. The arbitrary notches can vary based on simply user setup or the stretch in the cable.

Also, here's my biggest gripe: "Precise Power Readings" is mentioned several times on your site with regards to your Virtual Power product.



According to the chart above, one might believe that a budget Ascent Mag 3-L trainer would provide the same amount of data as a SRM Power Meter.

Your site does mention:

Tire Pressure
Fluctuation in tire pressure affects the resistance between your trainer and rear tire.

Trainer Tension
Make sure the tension between the rear tire and trainer are the same for each ride.
Which is great...but it doesn't say how it affects the numbers. And there doesn't seem to be a way to adjust for these two variables that could turn a 100w effort into a 250w effort using the same "click" number on a mag trainer. Not to mention the fact that tire roll-out is important, too.


Yes, your system take a speed measurement makes a best guess as to what power is being used to create that speed on the trainer. But, it's not "precise".



A LOT of people are confused by power meters, what they do, how they do it, how to interpret the numbers and make changes that will net an improvement. This tool doesn't help clear any of that up.
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Old 01-02-18, 04:54 PM
  #63  
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BTW, the speed + resistance level = “power” concept has been around for a while. The Cateye CS-1000 has that feature on the head unit.

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Old 01-02-18, 06:26 PM
  #64  
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For those following this thread, I conducted some tests this evening with the Feedback Sports Omnium trainer, a Fuji Track Elite, and 3 separate drum configurations. I ended up buying a third drum sled with the progressive resistance rollers, and I inverted one drum as Feedback Sports suggested. Below are my results at various RPMs and all 3 sled/drum configurations, plotted against average power and average speed. When I get a chance I'll conduct the test on my BMC Trackmachine, which has standard road tires on it at 120psi. The wattage should go up substantially on with this test, approx. 30 watts. Based on these results, when I travel, I will bring just one trainer and both the track and track/progressive hybrid sleds. The latter can be used for pre-race TT warm up, where I would need to get some higher power intervals in, and the former would be used for staying warm and spinning in between races. It's an easy solution, and the sleds can be swapped out in about 30 seconds.
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Results.png (90.8 KB, 110 views)
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Power.png (61.7 KB, 112 views)
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Speed.png (56.3 KB, 114 views)
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Old 01-02-18, 06:53 PM
  #65  
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Thanks, krispenhartung!

Are these findings what you'd expect?

It seems that all three have linear progressions. Did you expect the "Progressive" setup to be exponential?

Also, will you plot Speed vs Power as well? I'm curious to know if the power required to maintain the same speed is the same no matter what the gearing/cadence (e.g: How much power does it take to maintain 30mph on 50x15, 50x14, 50x13, and 50x12?). Or if acquiring the speed with different gearing/cadences calls for different power.

I think if you import into Golden Cheetah, you can get torque values as well. That way you can separate the torque from the cadence in the power equation.

Also, if you do that, you'll notice that torque drops off a cliff at a certain RPM It's because we can't fire the muscles fast enough to produce significant torque.
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Old 01-02-18, 07:09 PM
  #66  
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Using powermeters since 2006, I'd say nothing compares to real data. Precise, accurate data. I love it.. :-)
5% more power is sometimes very hard to get, and because of it I don't see high value on anything with a accuracy worst than 1,5% (90% confidence interval, I believe, what means you can can expect less than 0,5% out for 70% of data you get).

That said, I see value on having some "similar to power readings/estimatives" info.
It can give you better indicators of progress than heart rate, if you take care of all others parameters.
If you use same trainer, and "same" tire, pressure tire, roller screw position, etc., etc., you can get consistent values even from a training software estimative.
My point to friends that train with these tools is only that they don't have "watts info" - they have TRwatts (TrainerRoadWatts), StravaWatts, etc.
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Old 01-02-18, 08:28 PM
  #67  
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Originally Posted by carleton View Post
Thanks, krispenhartung!

Are these findings what you'd expect?

It seems that all three have linear progressions. Did you expect the "Progressive" setup to be exponential?

Also, will you plot Speed vs Power as well? I'm curious to know if the power required to maintain the same speed is the same no matter what the gearing/cadence (e.g: How much power does it take to maintain 30mph on 50x15, 50x14, 50x13, and 50x12?). Or if acquiring the speed with different gearing/cadences calls for different power.

I think if you import into Golden Cheetah, you can get torque values as well. That way you can separate the torque from the cadence in the power equation.

Also, if you do that, you'll notice that torque drops off a cliff at a certain RPM It's because we can't fire the muscles fast enough to produce significant torque.
Yup, I could do a million versions of this test. :-) I'll respond in segments here. I actually thought that the Omnium trainers with the progressive resistance drums were not linear, so I am surprised by this. The way the drums work is that the higher the speed, the more resistance they create. So this is odd. Maybe it's because of the high PSi I'm using? With just the track rollers, it was not even worth my while getting on the things. 32-39 watts, up to 140 rpm. I'm not even sure I'd use that drum sled for warm ups in between races now, but maybe it will be different with my BMC and normal tires. I use both TrainingPeaks and WKO4. But I have Golden Cheetah too. I'll check out the data later. Fun stuff.
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Old 01-02-18, 08:38 PM
  #68  
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Just for clarification, both your progressive tests were done on a sled with two progressive rollers, correct? If you flipped both progressive rollers 180 degrees, would you get even less resistance, or do they need to oppose each other? Would you be willing to do a test with a sled with one progressive and one track roller?
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Old 01-02-18, 08:55 PM
  #69  
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Originally Posted by carleton View Post
Thanks, krispenhartung!

Are these findings what you'd expect?

It seems that all three have linear progressions. Did you expect the "Progressive" setup to be exponential?

Also, will you plot Speed vs Power as well? I'm curious to know if the power required to maintain the same speed is the same no matter what the gearing/cadence (e.g: How much power does it take to maintain 30mph on 50x15, 50x14, 50x13, and 50x12?). Or if acquiring the speed with different gearing/cadences calls for different power.

I think if you import into Golden Cheetah, you can get torque values as well. That way you can separate the torque from the cadence in the power equation.

Also, if you do that, you'll notice that torque drops off a cliff at a certain RPM It's because we can't fire the muscles fast enough to produce significant torque.
Watts vs. Speed for each roller drum configuration attached...
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Old 01-02-18, 09:01 PM
  #70  
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Originally Posted by MarkWW View Post
Just for clarification, both your progressive tests were done on a sled with two progressive rollers, correct? If you flipped both progressive rollers 180 degrees, would you get even less resistance, or do they need to oppose each other? Would you be willing to do a test with a sled with one progressive and one track roller?
If you invert a progressive drum it basically becomes a track drum. That's what i was led to believe at least! But to verify it I would have to take a progressive drum off of my progressive sled and put it on the track sled. Before I do this, I'll ask Feedback Sports. I also sent them the data. So there are only three possible resistance configs, assuming that an inverted progressive drum is the same resistance as a track drum:

2 progressive drums in standard position (high resistance)
1 progressive drum in standard position and 1 inverted progressive drum (medium resistance)
2 track drums (low resistance)

1 track drum and 1 inverted progressive drum? Hmmmmmm. If it were in between the last two above in terms of resistance, that might be ideal.
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Old 01-03-18, 07:41 AM
  #71  
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What's with the bump at 115 rpm? Looking at the speed/cadence chart, if you were on the same gear, the speed per cadence should be the same regardless of the roller option.
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Old 01-03-18, 08:32 AM
  #72  
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Originally Posted by topflightpro View Post
What's with the bump at 115 rpm? Looking at the speed/cadence chart, if you were on the same gear, the speed per cadence should be the same regardless of the roller option.
I wonder if (s)he was switching pedaling styles right there (e.g. from "mashing" to "shuffling")
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Old 01-04-18, 12:43 AM
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Originally Posted by carleton View Post
I wonder if (s)he was switching pedaling styles right there (e.g. from "mashing" to "shuffling")
That's a good question. ("He" by the way). I was very focused on keeping my pedal stroke consistent across all the test intervals. It occurred on both tests, so what's the chances me repeating the same cadence idiosyncrasy twice on the same test interval in two separate tests and sled configurations? The only other test variable going on there is that it's the only test interval that is only a 5rpm increment, vs. 10 like the rest. Beyond this, I'm mystified.
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Old 01-04-18, 03:25 AM
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Originally Posted by krispenhartung View Post
That's a good question. ("He" by the way). I was very focused on keeping my pedal stroke consistent across all the test intervals. It occurred on both tests, so what's the chances me repeating the same cadence idiosyncrasy twice on the same test interval in two separate tests and sled configurations? The only other test variable going on there is that it's the only test interval that is only a 5rpm increment, vs. 10 like the rest. Beyond this, I'm mystified.
There are a handful of different ways to spin the cranks depending on what muscles you activate and the timing used. As you progress through the RPMs you may notice that you will actually switch teams of muscles used to turn the cranks, especially in the higher RPMs.

This obviously happens when you go from standing to seated in let's say a standing lap effort. But, it also happens when you do seated cadence drills on rollers/trainer.

115RPM might be where you go from using one set of muscles to another. The boost in power may be the fresh muscles coming into the game.

EDIT:

Also, there is a point where torque and cadence are optimal and there is a boost of power. This happens for many sprinters at around 120RPM when they are doing standing lap, 500M, or Kilo type efforts. They get a big boost of acceleration right there. It's evident in the power files. If you are watching team sprint and see man 1 pull away from the other rider(s) coming out of turn 2, that's when it's happening. This is exactly like the sweet spot in the torque range of a manual transmission car.

Maybe you are hitting that at 115RPM.

Last edited by carleton; 01-04-18 at 03:32 AM.
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Old 01-04-18, 07:23 AM
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Originally Posted by carleton View Post
There are a handful of different ways to spin the cranks depending on what muscles you activate and the timing used. As you progress through the RPMs you may notice that you will actually switch teams of muscles used to turn the cranks, especially in the higher RPMs.

This obviously happens when you go from standing to seated in let's say a standing lap effort. But, it also happens when you do seated cadence drills on rollers/trainer.

115RPM might be where you go from using one set of muscles to another. The boost in power may be the fresh muscles coming into the game.

EDIT:

Also, there is a point where torque and cadence are optimal and there is a boost of power. This happens for many sprinters at around 120RPM when they are doing standing lap, 500M, or Kilo type efforts. They get a big boost of acceleration right there. It's evident in the power files. If you are watching team sprint and see man 1 pull away from the other rider(s) coming out of turn 2, that's when it's happening. This is exactly like the sweet spot in the torque range of a manual transmission car.

Maybe you are hitting that at 115RPM.
Very interesting! Thanks for that explanation. Just out of curiosity, I looked at my data for my 2017 State Championship Road race win, which occurred in the last 900 meters when I sprinted ahead of the pack, and my cadence was almost at 115rpm!
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