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SpinScan
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Hi Everybody,

I am curious about the value that Computrainer's SpinScan provides to fitting customers. From what I'm seeing and hearing, people want some sort of measurable metric to say "yeah, the money I spent on my fit was worth it". They want to say "I gained X watts thanks to my fit!" These are some open, somewhat rhetorical questions, and any thoughts are appreciated:

1. Can SpinScan really demonstrate the effects of a good versus not-so-good position?

2. Is SpinScan really all that accurate? I have a hard time understanding how it could be very accurate when you are measuring at the rear wheel. I would think that pedal-based or crankarm-based solutions have the potential to be more accurate, but obviously you can't just throw on a set of Garmin Vectors when the customer is using Speedplays.

3. Are there any alternatives to SpinScan? Could I get just as useful information from a CycleOps Powerbeam Pro?

4. Going back to providing measurable gains, is there any value in trying to demonstrate wattage changes? Do you let the customer see their output live? The last time I was fit by somebody else, he let me see my SpinScan live, but that really just allowed me to immediately see the effects of my pedaling technique and adjust accordingly. At the end, he claimed I gained 15 watts, but I really don't buy it - he never measured heart rate or even paid attention to my cadence.

Thanks for any thoughts!
Travis

Travis Rassat
Vector Cycle Works
Noblesville, IN
BikeFit Instructor | FMS | F.I.S.T. | IBFI
Toughman Triathlon Series Ambassador
Last edited by: Travis R: Mar 8, 14 5:39
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Re: SpinScan [Travis R] [ In reply to ]
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I tend to find spin scan more a diagnostic of the client's pedalling ability/ form. I find that it is a really good thing to show them when we get to the end of a session. I can show them how they are pedalling at that point in time then I can coach them and show graphically how doing the classic, pull across the bottom AKA wiping mud off your shoe, and over the top can improve their power distribution and left right balance. It has something to do with the fitting in that if their bike fit was really out of whack their pedalling fluidity was effected then it really shows and you can show a before and after. I would not show them any metrics while they are being adjusted because it is not the way they normally work and can cause distraction and targeting which just confuses things when you want them to focus of riding in "their" normal way.

So it is a yes and no sort of thing for me, others may well see it differently and as with everything it is a tool and how you use it depends on what you have for a philosophy.
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Re: SpinScan [s5100e] [ In reply to ]
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Thank you for your thoughts. I can appreciate your point - like you say, it is more of a diagnostic of their pedaling ability and form. If the fit is good, hopefully it does not interfere with that. I think it is key to set realistic expectations of what something like this can do for them. Thanks again!

Travis Rassat
Vector Cycle Works
Noblesville, IN
BikeFit Instructor | FMS | F.I.S.T. | IBFI
Toughman Triathlon Series Ambassador
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Re: SpinScan [Travis R] [ In reply to ]
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I agree, in fact a fitting should make it "easier" for a person to achieve a good/ fluid pedalling dynamic. I had one person who was really a runner and had less experience cycling and it really showed by how square their pedal stroke was. He could get it better with coaching but it will take him time and practice to improve. I like to do follow up and see how they are getting along to ensure that the changes are sticking and they are in fact improving.
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Re: SpinScan [s5100e] [ In reply to ]
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Thanks again for your thoughts. I think if we can give people an opportunity to see how their pedaling dynamic affects their output and get a chance for them to feel that, it adds value to the fit. The hard part is keeping that feel when they don't have the SpinScan screen available to them all the time... Are there any alternatives? The Garmin Vectors and other power meters seem to offer this potential, but so far, I haven't seen anything else quite like SpinScan.

Travis Rassat
Vector Cycle Works
Noblesville, IN
BikeFit Instructor | FMS | F.I.S.T. | IBFI
Toughman Triathlon Series Ambassador
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Re: SpinScan [Travis R] [ In reply to ]
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There are some widely held misconceptions about pedaling bicycles that Spin Scan contributes to. If you use it during a bike fit, keep in mind that the implication that a higher spin scan score relates to greater efficiency and/or greater power is contradicted by the relevant scientific literature. Fitting to optimize spin scan typically will lead to seat heights on the low side of "normal" which may make knee injury more likely.
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Re: SpinScan [davidkohli] [ In reply to ]
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davidkohli wrote:
There are some widely held misconceptions about pedaling bicycles that Spin Scan contributes to. If you use it during a bike fit, keep in mind that the implication that a higher spin scan score relates to greater efficiency and/or greater power is contradicted by the relevant scientific literature. Fitting to optimize spin scan typically will lead to seat heights on the low side of "normal" which may make knee injury more likely.

I agree with you in a general way, as I said above"I would not show them any metrics while they are being adjusted because it is not the way they normally work and can cause distraction and targeting which just confuses things when you want them to focus of riding in "their" normal way. " to me the benefit of spin scan is after the fitting and is not a metric to aid in the fitting process, ie setting seat height, set back, etc, etc ,etc. I consider the use of spin scan as a coaching tool only after the fitting is completed.
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Re: SpinScan [Travis R] [ In reply to ]
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We have just installed the new GURU fit unit where we utilise the Spin Scan feature as a fit "verification" tool and have found it useful.

We turn it off during the initial fit procedure until we are getting adjustments down to a few mm that we are happy with, we use a constant load up to this point monitoring cadence and visual cues in the process.

Once we turn the Spin Scan program on, people will definitely change their pedal style and yes it can be distracting to achieving a "best fit", so while the spin scan is on, we get them to concentrate on their cadence reading on the handlebar mount.

We ask them to maintain a constant cadence (eg 100rpm) and set the incline to level 1,2 or 3 depending on their fitness and keep their heart rate at the same level.

We find that when adjusting their saddle height to a "poor" position (like 20mm too low) their power actually goes up, as they have to push harder on the pedals to maintain the desired cadence, or their cadence drops off - but both results would be interpreted as signs of inefficiency in their "fit".

We have found that immediately after a position change (because with GURU its seamless and they are still riding) their power spikes a bit as they "adjust" then settles higher or lower depending of efficiency of fit achieved.

So, we have been finding utilising the Spin Scan feature that a more "efficient" fit is creating a lower power reading, keeping all other parameters constant. (heart rate / gradient and cadence). As the system is quite a new toy for us we have also been verifying achieved fits by classic methodology of knee over point of axle plus knee angle and ankle position, pretty much 96% of them, to our surprise, have been spot on.

We set up a set of Garmin pedals and while the readings were different (in power achieved) and the timing possibly more accurate the results were similar (more efficient = less force (power) required)

My question is are we on the right track? in that - a more efficient position would actually result in a lower power reading as you do not have to push on the pedal as hard to maintain your cadence going up a set incline (given same heart rate).

So for us the Spin Scan feature has been a good verification tool - providing we are actually using it correctly.

Anyone else have similar experiences ?
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Re: SpinScan [cbdhugh] [ In reply to ]
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cbdhugh wrote:
We find that when adjusting their saddle height to a "poor" position (like 20mm too low) their power actually goes up, as they have to push harder on the pedals to maintain the desired cadence, or their cadence drops off - but both results would be interpreted as signs of inefficiency in their "fit".

We have found that immediately after a position change (because with GURU its seamless and they are still riding) their power spikes a bit as they "adjust" then settles higher or lower depending of efficiency of fit achieved.

So, we have been finding utilising the Spin Scan feature that a more "efficient" fit is creating a lower power reading, keeping all other parameters constant. (heart rate / gradient and cadence). As the system is quite a new toy for us we have also been verifying achieved fits by classic methodology of knee over point of axle plus knee angle and ankle position, pretty much 96% of them, to our surprise, have been spot on.

We set up a set of Garmin pedals and while the readings were different (in power achieved) and the timing possibly more accurate the results were similar (more efficient = less force (power) required)

My question is are we on the right track? in that - a more efficient position would actually result in a lower power reading as you do not have to push on the pedal as hard to maintain your cadence going up a set incline (given same heart rate).

Wow, this is some great info, although I have to admit, I'm confused. Since power is measured as output, if all other things are consistent - heart rate, cadence, incline, etc., wouldn't a higher power reading indicate a more efficient position? Basically, the engine is producing the same power, so the more power that is effectively transferred to the measuring device, the better.

Inversely, if the power was the same, but the heart rate lower, wouldn't that also be more efficient? In your example where you drop the seat too low, wouldn't the heart rate go up?

Thanks for your thoughts!

Travis Rassat
Vector Cycle Works
Noblesville, IN
BikeFit Instructor | FMS | F.I.S.T. | IBFI
Toughman Triathlon Series Ambassador
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Re: SpinScan [cbdhugh] [ In reply to ]
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wouldn't it be more informative to look at the shape of the polar scan? When a rider is pushing the pedals the polar scan should pinch in the middle, the ATA will be either too early or too late, depending where they are pushing, and Spin Scan number will drop away or decrease, at the same power output, while if they are at a good fit location then the polar scan should start to look more oval and the ATA should be nearer 90, and the spin scan number should move towards 100, certainly I look for a number better than 70. The 3 measures together become information that can help you, power alone is not the measure, I have not tried heart rate but if the HR is lower after a 5 minute hard effort at a same power output that is definitely more efficient. This info can be found in a number of books on cycling power by Friel or Coggan and Allen.
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Re: SpinScan [s5100e] [ In reply to ]
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I agree that the spin scan is an excellent tool and we utilise it during the fit to explain the best efficiency to achieve in pedal style.
As Computrainer explain it its not a "magic bullet" http://www.computrainer.com/rm1/Online_Help/SpinScan.htm
SpinScan offers efficiency improvements a few ways.
The SpinScan number (SS) - showing torque efficiency as defined above. Ranges from low 30's to high 80's (typical). There is no ideal number, but the goal is to make this number grow, over time, while maintaining the same wattage/RPM/Speed relationships.

In their process they also talk of holding all other factors constant when using one parameter as a reference. So as Travis R suggested "Inversely, if the power was the same, but the heart rate lower, wouldn't that also be more efficient? In your example where you drop the seat too low, wouldn't the heart rate go up? " this would be correct.
A more inefficient position would create a higher heart rate.



I was looking for a measurable variable that we could utilise fairly fast and accurately. The only real test is to do a 8 min max power output test, but the parameters are too hard to keep constant. Likewise Heart rate needs some time to "kick in" and show effects as there is a bit of a lag and so is less "instant" like we are achieving with power.

We could use any of the parameters as a verification tool of efficiency, cadence, Heart rate, spin scan or power.


The two thoughts are that.
1: All other variables have to be kept near constant in order to get efficient reading of the measuring variable ( be it cadence / HR / Power or spin). So if you are using HR as the measure of efficiency then power, cadence and gradient need to remain constant. Like wise if cadence is the measured variable then power / HR and gradient need to remain constant.
2: The assumption of- with greater efficiency in fit required power will go down (or HR down or cadence up) is the bigger question.


Assumption 1 is basic science, so that's already been verified by much smarter people for many years.


For 2 the assumption comes from we are measuring "power" in a fit situation as pressure on the pedals, that is how much force is required to shift the cranks round at 100 rpm.
We are actually measuring how efficiently they can achieve 100rpm (or 60rpm / 80rpm or any number).
If we look at a crank and bearing interface as an analogy
Loose ball bearings with oil - spin with a fingertip pressure - less force required.
Seized cartridge bearings with lots of rubber seals - lots of force required to spin.


So less force required to achieve a given output should be a sign of greater efficiency.


It may be that using the GURU DFU system is allowing us to better track power as a measurement, we never did before as people had to get on and of the bike so measuring would been interrupted and not consistent. I do not think the numbers are accurate enough to be the holy grail of fit or to be the only tool of reference or verification.


If we do not follow F.I.S.T protocol or try to use power only or cadence only, the positions achieved come up weird. It still requires a fitters skill.
But as a verification tool of "this is the best fit for you (the customer) because....." it is proving to be excellent.

Thoughts and critique appreciated.
Hugh









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Re: SpinScan [cbdhugh] [ In reply to ]
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cbdhugh wrote:

My question is are we on the right track? in that - a more efficient position would actually result in a lower power reading as you do not have to push on the pedal as hard to maintain your cadence going up a set incline (given same heart rate).

No, you have a fundamental misunderstanding of power. Power is what makes the bike move, cadence is just a component of power.
Power is torque x CPV, or as a simplified view - force x cadence
If cadence is fixed then so is the force required to achieve a given power. If power drops while everything else stays the same something is wrong.
What you want is for the rider to be able to produce more force for the same HR (with same or higher cadence), possibly by removing constrictions on blood flow, moving into an optimal range of motion for the working muscles or by reducing wasted energy going to non-drive muscles.

Pushing harder on the pedals is the whole point of training to get faster.

I've yet to determine or learn of a good reason to use spinscan in a fit beyond having visual feedback during technique discussions.

Speedtheory
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Re: SpinScan [cyclenutnz] [ In reply to ]
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I fully agree with this response, I would only use spin scan in a coaching/ teaching aspect to help clients understand the dynamics of a good pedalling technique. In other words if they are fit on the bike well, there should be less issue with restricted/ constricted movement and so they should have the freedom to pedal properly. So at the end of the fitting is a good time to explain to the rider hoe to improve their pedalling technique to get the most out of the fitting and to help them get the feeling of an good pedalling technique.

cyclenutnz wrote:
cbdhugh wrote:


My question is are we on the right track? in that - a more efficient position would actually result in a lower power reading as you do not have to push on the pedal as hard to maintain your cadence going up a set incline (given same heart rate).


No, you have a fundamental misunderstanding of power. Power is what makes the bike move, cadence is just a component of power.
Power is torque x CPV, or as a simplified view - force x cadence
If cadence is fixed then so is the force required to achieve a given power. If power drops while everything else stays the same something is wrong.
What you want is for the rider to be able to produce more force for the same HR (with same or higher cadence), possibly by removing constrictions on blood flow, moving into an optimal range of motion for the working muscles or by reducing wasted energy going to non-drive muscles.

Pushing harder on the pedals is the whole point of training to get faster.

I've yet to determine or learn of a good reason to use spinscan in a fit beyond having visual feedback during technique discussions.
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Re: SpinScan [s5100e] [ In reply to ]
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Power is not the olny thing to look at Spin scan is a tool that can be used to help find a more efficent pedal stroke. If I can inable a cyclist to maintain the same speed with a lower hart rate I have given them a bigger buffer on going anreobic. I may have lowered there caloric needs. and that might aid to a better day tomorow.


Happy Freedman
Orthotic Consultant
Bike Fitting Specialist
Prosthetics and Orthotics/DME
Hospital for Special Surgery
510 East 73rd Street, Suite 201
New York, NY 10021


Happy
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Re: SpinScan [Happy] [ In reply to ]
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Happy wrote:
Power is not the olny thing to look at Spin scan is a tool that can be used to help find a more efficent pedal stroke. If I can inable a cyclist to maintain the same speed with a lower hart rate I have given them a bigger buffer on going anreobic. I may have lowered there caloric needs. and that might aid to a better day tomorow.

How are you defining 'more efficient' if you're not looking at pw:hr?
Indoors fit tells you nothing (unless you have methods for assessing) about whether the rider can maintain the same speed for a lower HR on the trainer - you may have worsened aerodynamics in making them more comfortable. Or simply be measuring the effect of a fluid trainer or tyres heating up...
Also, going anaerobic is not the concern for a triathlete - glycolytic is such a short duration energy system that it's near meaningless for racing purposes. Accumulating too much TSS (ie too long at too high a fractional VO2 or MLSS) is what we're looking to avoid by good pacing and an efficient setup.

Speedtheory
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Re: SpinScan [cyclenutnz] [ In reply to ]
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When fitting I'm not just worrying about racing I'm also worried about training so when fitting I worry as much about the training bike to do about the racing bike. We spend much more time training and competing that should be as much of a priority setting up the bike for competition'. As far as setting up eight euro bike I worry just as much but the physiology of the rider did you want a regular bike. If you're setting up for a try you should be monitoring heart rate blood pressure pulse oximeter if you have one along with other tools to make sure you're making the rider is as efficient as possible. If you cook them on the ride leave them with nothing left for the run, dynamics is important but it's not the only thing to look at if I can keep your heart rate lower I can make useless calories I can possibly reduce the amount of fluids need to take it. What's produced are important as explored the coefficient but will drag coefficient gets in the way of the functioning body it it's no longer an advantage. just to find things that advantage clients needs and abilities look at everything aero dynamics is but a small part of the puzzle.

Happy
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Re: SpinScan [Happy] [ In reply to ]
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I'd be very interested to hear how you think the oximeter and BP cuff are adding value.
If you're looking at caloric effect you need to be measuring RER too... Or just rely on the fact that watts are joules per second and therefore tell you what the burn rate is. Beyond that you would have to be tracking GME to be able to state that efficiency had improved (and I've never found a study showing that bike position can do that).

Speedtheory
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Re: SpinScan [cyclenutnz] [ In reply to ]
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You missed presentations at the International Cyclefit Symposium in February and the Medicine of Cycling in Colorado springs last August.. There is also the researc of Inigo San Milan . University of Colorado Denver, and Team Garmin.
there is a lot of information to be found. its not published under training cycling,or triathalon. You have to look for research in pulminary function,vasculer function and other related subjects.Most of the interesting research is done on diabetics, and people with respritory priblems.Their is money for that kind of sicence.We just have to filter threw that researc for little jems.
Happy

Happy Freedman
Orthotic Consultant
Bike Fitting Specialist
Prosthetics and Orthotics/DME
Hospital for Special Surgery
510 East 73rd Street, Suite 201
New York, NY 10021

Happy
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