How to train for 20km TT

fixedlegs2012
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Re: How to train for 20km TT

Postby fixedlegs2012 » Tue Nov 10, 2015 5:07 pm

THE PRAXIS conversion bottom bracket is the GOLD standard in bottom brackets, cant recommend it highly enough. Have one on my TIME RXRS. And a XD-15 on the Felt AR1.

Something Ive adapted, on the screen I have 3sec avg power, cadence, heart rate and distance. I only ride to my power for the distance and what I can hold. It has worked for me. Once you know all your power numbers it may work for you.
I also don't get as low as I could as I lose some more power, its a trade off between aero and loss of power.
Return that helmet and buy one with a visor, if you cant get the head down look at the KASK Bambino, otherwise Lazer Wasp.
If you don't use them already, booties, Castelli.
Speed/Skinsuit is a must.

linds
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Re: How to train for 20km TT

Postby linds » Fri Nov 20, 2015 6:33 pm

When I used my old Sigma bike computer I was able to download the rides and visually overlay one ride with another and be able to compare rides in graphic and mathematical detail.
Using this I could also isolate any part of a ride ( zoom in ) I wanted to look at closely...and compare that with the same part of the ride ridden at another time.

Garmin connect cant do any of this - it is just a ride with some basic metrics.
I can set time or distance alerts to segment the ride which is ok but I cant do any visual overlays or mathematical comparisons between rides or parts of rides on the same page.

Is there any software available that can read my Garmin and replicate what the Sigma software does?

thanks

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kb
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Re: How to train for 20km TT

Postby kb » Fri Nov 20, 2015 6:39 pm

linds wrote:When I used my old Sigma bike computer I was able to download the rides and visually overlay one ride with another and be able to compare rides in graphic and mathematical detail.
Using this I could also isolate any part of a ride ( zoom in ) I wanted to look at closely...and compare that with the same part of the ride ridden at another time.
Online, Strava will do it if the part of interest is a segment. If you prefer desktop, Golden Cheetah has a comparison mode. 3.3 Release Candidate is looking pretty good.
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linds
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Re: How to train for 20km TT

Postby linds » Sat Nov 21, 2015 7:09 pm

Hi kb thanks for the suggestions.
I have had a bit of look at Cheetah..cant see how to directly compare one ride with another by use of overlay and user selected segment metrics. But there is a lot there so I may not have found it yet. Interesting product.
Does the subscriber level of Training Peaks do what I want I wonder?

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Alex Simmons/RST
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Re: How to train for 20km TT

Postby Alex Simmons/RST » Sun Nov 22, 2015 6:20 am

WKO+ has multi file range analysis that enables overlay of as many ride segments as you like, although it provide time based comparisons rather than distance based ones. The feature is not yet in WKO4.

The method to do your own analysis is to export the data for each segment you wish to compare into a spreadsheet and plot them.

linds
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Re: How to train for 20km TT

Postby linds » Sun Nov 22, 2015 11:48 am

Thanks Alex.
I found out how to do it on Cheetah - using the Intervals/Segments functions.
Thks again kb.

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Re: How to train for 20km TT

Postby linds » Mon Nov 30, 2015 12:51 pm

Had a play with Golden Cheetah Aerolab.
I have either done something wrong or I have a very very crap CDA.
Followed protocols etc this morning - a nice still morning.
0.31 with full kit on! Is that possible?
I will try it again on a different stretch of road at some stage.

dalai47
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Re: How to train for 20km TT

Postby dalai47 » Mon Nov 30, 2015 1:23 pm

Possible as you are tall, though that is excessively high! You should be able to get it a lot lower than that...

I went into the tunnel with what I thought was a good position and was around 0.26. I found in the wind tunnel even subtle changes can make a big difference ie. bringing the hands back along the extensions which I used to do on climbs increased my CdA by 10%!

I am 183cm and was able to significantly improve my CdA from that initial 0.26, so it is possible to get far more slippery!

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Alex Simmons/RST
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Re: How to train for 20km TT

Postby Alex Simmons/RST » Mon Nov 30, 2015 3:03 pm

linds wrote:Had a play with Golden Cheetah Aerolab.
I have either done something wrong or I have a very very crap CDA.
Followed protocols etc this morning - a nice still morning.
0.31 with full kit on! Is that possible?
I will try it again on a different stretch of road at some stage.
0.31m^2 is entirely possible. Much depends on the individual and your position and equipment.

If it was a full TT rig and position, that is not a good CdA though.

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Re: How to train for 20km TT

Postby linds » Mon Nov 30, 2015 4:03 pm

Alex Simmons/RST wrote:
linds wrote:Had a play with Golden Cheetah Aerolab.
I have either done something wrong or I have a very very crap CDA.
Followed protocols etc this morning - a nice still morning.
0.31 with full kit on! Is that possible?
I will try it again on a different stretch of road at some stage.
0.31m^2 is entirely possible. Much depends on the individual and your position and equipment.

If it was a full TT rig and position, that is not a good CdA though.
Dalai and Alex....This was not the response I was hoping for. But thanks.
It was indeed full TT rig and position - except I had a t shirt under the skin suit - that was the only difference.
Feck..where do I start to look for improvements?
I would have thought I would at least be under 0.3 given the effort I have gone to with equipment and physical adaption.
Also..I may be tall but I have thin shoulders and arms, narrow chest, skinny legs etc and had thought that at least those attributes of my physique would be in my favour.
Anyway I will confirm my numbers on another, shorter, more appropriate up and back course and go from there I suppose as I am not overly confident that what I have done was optimal.

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Re: How to train for 20km TT

Postby dalai47 » Mon Nov 30, 2015 4:36 pm

linds wrote:Dalai and Alex....This was not the response I was hoping for. But thanks.
It was indeed full TT rig and position
Actually see the above as a good thing. Means you have room to get a lot more aero... :wink:

Biggest improvement normally is getting your head out of the wind by shrugging and turtling.

Unfortunately some changes may still be in equipment selection. I saved 10 Watts just by swapping aero helmets. The other ~33 Watts savings I found were mainly around getting my big fat head out of the wind which included dropping 2cm in spacers.

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Re: How to train for 20km TT

Postby linds » Mon Nov 30, 2015 4:54 pm

Latest position: (doesnt look that unaero to me)

Frt

Image

Side

Image

I could drop at the front a little now without too much trouble I think.

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Re: How to train for 20km TT

Postby Alex Simmons/RST » Mon Nov 30, 2015 8:44 pm

dalai47 wrote:
linds wrote:Dalai and Alex....This was not the response I was hoping for. But thanks.
It was indeed full TT rig and position
Actually see the above as a good thing. Means you have room to get a lot more aero... :wink:

Biggest improvement normally is getting your head out of the wind by shrugging and turtling.

Unfortunately some changes may still be in equipment selection. I saved 10 Watts just by swapping aero helmets. The other ~33 Watts savings I found were mainly around getting my big fat head out of the wind which included dropping 2cm in spacers.
Getting reliable aero data from self testing requires some rigour and knowledge of the testing pitfalls.

How about running through your methodology, data capture and assumptions, see if we can find any obvious flaws?

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Re: How to train for 20km TT

Postby linds » Tue Dec 01, 2015 5:45 pm

Thanks Alex
The one variable that I am not sure of, and Cda varies significantly with it, is the Crr - tyre rolling resistance.
I am using Vittoria Corsa CX tubulars at about 90psi.
The road surface is quite smooth and regular biutmen.
What is a realistic Crr? I have used 0.004 but 0.005 improves the Cda quite a bit.

Short of this, I think my other numbers ( atmospherics) are good. But precision of turning points could have been better.
The data is via a Garmin 510 and a Stages power meter. I used the GPS for speed - this is another weak point.


Lindsay

Edit:
Online I have found a Crr figure of 0.0054 (http://cyclinguphill.com/vittoria-corsa-evo-cx-review/" onclick="window.open(this.href);return false;) for Vittoria Corsa Evo tubulars. My rear is one of these, the front a Cx.

This figure changes my Cda to 0.265. Wow that is better. But still needs confirming.

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Re: How to train for 20km TT

Postby Alex Simmons/RST » Wed Dec 02, 2015 7:59 am

linds wrote:Thanks Alex
The one variable that I am not sure of, and Cda varies significantly with it, is the Crr - tyre rolling resistance.
I am using Vittoria Corsa CX tubulars at about 90psi.
The road surface is quite smooth and regular biutmen.
What is a realistic Crr? I have used 0.004 but 0.005 improves the Cda quite a bit.

Short of this, I think my other numbers ( atmospherics) are good. But precision of turning points could have been better.
The data is via a Garmin 510 and a Stages power meter. I used the GPS for speed - this is another weak point.


Lindsay

Edit:
Online I have found a Crr figure of 0.0054 (http://cyclinguphill.com/vittoria-corsa-evo-cx-review/" onclick="window.open(this.href);return false;) for Vittoria Corsa Evo tubulars. My rear is one of these, the front a Cx.

This figure changes my Cda to 0.265. Wow that is better. But still needs confirming.
Well Crr is a factor for sure and as you see, not knowing it with certainty means calculation of the absolute CdA may have substantial bias error. However it is only a bias error, so that's actually not such a bad thing for the average self aero testing punter. It's the uncontrollable and/or unmeasurable factors that are the real problem.

Whatever method you use, ultimately they are all balance sheet equations for energy demand and supply, some factors of which we know with more certainty than others, and rearranged to provide CdA as the output from all the inputs (measured and/or assumed).

With such methods (like Aerolab* based on Robert Chung's virtual elevation approach) the normal method is to fix a Crr value and assume all changes that "level the VE plot", or at least match actual elevation are due to changes in CdA.

In some situations that's a reasonable assumption to make, but not always, and understanding what those exception cases are matters. e.g. things like power meter variability, which will happen with a Stages to some degree**, accurate speed data (use wheel speed sensor and not GPS), wind (very hard to quantify precisely, it only takes a slight change of wind, or a vehicle to pass to alter the values), air density variations (not so hard to quantify with good measuring equipment), ability to maintain a position, not using brakes, riding past the same location each lap etc etc.

If you have a good testing venue (shorter would be better, BTW that's me on ST) then getting the absolute Crr value correct isn't a necessity provided you use same tyres/pressure and venue, and know the impact of temperature variations on Crr. Then all you need to do is to work out whether set up A is better/worse than set up B, and by what relative amount. That's actually really useful to know and is generally what most people are after.

If however you want to more precisely determine the actual Crr (i.e. prise apart the CdA/Crr pair), then that requires another level of testing rigour, different test protocol and data analysis techniques. Several methods exist but very few bother, instead applying the practical principle of working out what set up is better/worse and by what relative amount and not being as concerned with absolute accuracy of CdA (which if Crr is wrong translates to a bias error in CdA), but instead being more concerned with the accuracy of measured differences between set ups.

Sometimes it's possible to prise the Crr answer out of existing data but the errors in Crr measurement are pretty sensitive to test method and can be large. It's usually just easier to assume it's a constant (or at least an average value for the course chosen) and assume changes are aero related and to spot anomalies.



* Aerolab by my good friend Andy Froncioni is a nice more interactive version of a spreadsheet of Robert Chung's VE approach I made available in the public domain and helped to popularise many years ago. I also created user friendly versions of the more "classical" regression testing approach spreadsheet as described by Martin, Coggan et al. There are other method's, like Shen method, which is like VE but inspects the concavity of the lap by lap VE lines, which can in some cases help to prise apart the CdA/Crr pair.

** There will come a point where Stages data may not be consistent enough due to the assumption of constant power asymmetry. What this means is that the error bars may end up being bigger than the change you are seeking to test. The smaller the change the more reliability needed in the data and the conditions.

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Re: How to train for 20km TT

Postby linds » Wed Dec 02, 2015 9:53 am

Thanks Alex I appreciate your time and expertise.
Out of the data that I currently have in Golden Cheetah - it is telling me that the improvement in Cda by using my deep dish front over my road front is 0.01. That is - Cda with deep dish (88mm) is 0.265 and with road front it is 0.275. Is this likely to be somewhere in the ballpark? It doesnt 'feel' faster to me, nor have I done my best times with it, but logically it should be. ). 0.01 seems a lot.

I actually have a second hand Quarq (S975) waiting to go on. When I do this I will also put on the speed sensor for a better run of tests.

Improvements in the future may include
-better aero bars
-better helmet
-better skinsuit
-better position

And of course always working on improving FTP

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Re: How to train for 20km TT

Postby Alex Simmons/RST » Wed Dec 02, 2015 11:15 am

0.01m^2 is plausible. Whether it's correct is another question :)

TT speed is an energy supply and demand equation.

Supply is obviously about your fitness (training) and pacing (practice, strategy and learning to find where the performance edge is), while demand is working on reducing the forces opposing your forward motion (for a given velocity), and aerodynamics is the biggest factor by far. In a TT 80+% of your energy is used to overcome air resistance. 90+% if it's flat and smooth.

Your list is a good one, position is #1, bars affect that, and helmet and skinsuits do work well if you choose right ones for you.

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Re: How to train for 20km TT

Postby linds » Fri Mar 04, 2016 4:56 pm

Well I have been working away and with some great guidance from drpcoaching.blogspot.com.au I have got my ftp up from about 220 in October to about 250 now. My goal time in the local club TT was for a neat 24 minutes over the 16km course ( 40kph). I have gradually improved my time to now being about 20 seconds off goal time the last 3 efforts. The last race is next week.
I need to find a bit over 1 second per km and will need some ok weather conditions to do it.
I have learned a lot about ftp and TT pacing over the last few months.
If I don't do it in a club race then I will keep working towards it on my own. Would like to get my ftp up to 260.
Think my 52yo dodgy knees are surviving all this rather well which is great.

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Re: How to train for 20km TT

Postby mikesbytes » Fri Mar 04, 2016 8:42 pm

Hi Linds, hopefully the weather gods will deliver the 1 second per k
If the R-1 rule is broken, what happens to N+1?

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Re: How to train for 20km TT

Postby linds » Sun Mar 13, 2016 12:32 pm

I didnt quite reach my goal time/speed during the local TT races so now I will work towards it solo.
I went through my 'speed history' - this was an interesting exercise.
Started with my cheap Verite roadie around April 2013

Date TT speed
April 2013 33
May 34.4 (added clip on TT bars)
Dec 35.2
Mar 2014 34.4
April 35.9
Sept 36.0
Nov 36.4 ( added aero hat and wheels)
Dec 36.5 ( Added TT bike)
Jan 2015 37
May 38.4
Injury/10 weeks no riding, no training.
Sept 34.2 (!) Start power meter training ftp 220
Nov 36.9
Dec 37.7 ftp 240
Feb 2016 38.0
Feb 2016 39.1 ftp 250
March 39.3 ( did this speed twice in differing conditions)

And that is where I am up to. The body is standing up to this quite well but the heat the last couple of months really has not helped my cause. I expect to see a performance improvement over the next month or 2 as the weather moderates.

I am having this week off and will resume training with a goal to increase ftp to 260 and to be able to avg 40 on local TT courses over 16km.
I am putting on a better set of aero bars ( 3T Aura) tomorrow so this will slightly change my position and require some adaptation time.
Then I will retest ftp and go from there.

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Re: How to train for 20km TT

Postby mikesbytes » Sun Mar 13, 2016 12:41 pm

In 2 years your added 6kph, that's amazing
If the R-1 rule is broken, what happens to N+1?

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Re: How to train for 20km TT

Postby koshari » Sun Mar 13, 2016 3:01 pm

Good work linds. You have inspired me to dig up my old tri bars and fit them to my flatbar roadee that lives at our beach place. Its totally flat down here compared to where i regularly ride. See if i can get some more speed out of the old beach steed.
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Re: How to train for 20km TT

Postby GJM » Sun Mar 13, 2016 3:20 pm

Brilliant info and, it goes without saying, achievements. Thanks for sharing, and congratulations.

Just a question on your FTP - do you test it via a 20 min test, or do you do it over a full hour?
And do you run the test on the trainer, or outdoors?

TIA.

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Re: How to train for 20km TT

Postby foo on patrol » Sun Mar 13, 2016 5:06 pm

linds wrote:I didnt quite reach my goal time/speed during the local TT races so now I will work towards it solo.
I went through my 'speed history' - this was an interesting exercise.
Started with my cheap Verite roadie around April 2013

Date TT speed
April 2013 33
May 34.4 (added clip on TT bars)
Dec 35.2
Mar 2014 34.4
April 35.9
Sept 36.0
Nov 36.4 ( added aero hat and wheels)
Dec 36.5 ( Added TT bike)
Jan 2015 37
May 38.4
Injury/10 weeks no riding, no training.
Sept 34.2 (!) Start power meter training ftp 220
Nov 36.9
Dec 37.7 ftp 240
Feb 2016 38.0
Feb 2016 39.1 ftp 250
March 39.3 ( did this speed twice in differing conditions)

And that is where I am up to. The body is standing up to this quite well but the heat the last couple of months really has not helped my cause. I expect to see a performance improvement over the next month or 2 as the weather moderates.

I am having this week off and will resume training with a goal to increase ftp to 260 and to be able to avg 40 on local TT courses over 16km.
I am putting on a better set of aero bars ( 3T Aura) tomorrow so this will slightly change my position and require some adaptation time.
Then I will retest ftp and go from there.
Find some long not so steep climbs (300-400mtrs) and do repeats of 3 or 4 on them with 5min breaks, twice a week :idea:

Foo
I don't suffer fools easily and so long as you have done your best,you should have no regrets.
Goal 6000km

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Re: How to train for 20km TT

Postby linds » Sun Mar 13, 2016 6:04 pm

foo on patrol wrote:
linds wrote:I didnt quite reach my goal time/speed during the local TT races so now I will work towards it solo.
I went through my 'speed history' - this was an interesting exercise.
Started with my cheap Verite roadie around April 2013

Date TT speed
April 2013 33
May 34.4 (added clip on TT bars)
Dec 35.2
Mar 2014 34.4
April 35.9
Sept 36.0
Nov 36.4 ( added aero hat and wheels)
Dec 36.5 ( Added TT bike)
Jan 2015 37
May 38.4
Injury/10 weeks no riding, no training.
Sept 34.2 (!) Start power meter training ftp 220
Nov 36.9
Dec 37.7 ftp 240
Feb 2016 38.0
Feb 2016 39.1 ftp 250
March 39.3 ( did this speed twice in differing conditions)

And that is where I am up to. The body is standing up to this quite well but the heat the last couple of months really has not helped my cause. I expect to see a performance improvement over the next month or 2 as the weather moderates.

I am having this week off and will resume training with a goal to increase ftp to 260 and to be able to avg 40 on local TT courses over 16km.
I am putting on a better set of aero bars ( 3T Aura) tomorrow so this will slightly change my position and require some adaptation time.
Then I will retest ftp and go from there.
Find some long not so steep climbs (300-400mtrs) and do repeats of 3 or 4 on them with 5min breaks, twice a week :idea:

Foo
Thks Foo
What kind of intensity?

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