Racing with a power meter. Link to my latest tt.

A light bike doesn't replace good fitness.

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markc
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Joined: Thu May 17, 2007 2:23 am

by markc

Yeah, TT thread!!! Here is a shot from our state TT. 40km, flat course, ran 57:08 this year on a decent but not great leg day. Power right around 250w average for this distance. For 10 miles I can get to the high 260s and on a flat course, no wind will run under 22 min (with the bike as shown).

Image


Juan - using the same bars / extensions as you and here is how I have my computer set up:

Image

Just a piece of delrin rod cut to size and rounded on the ends. The Garmin mount just sits on top of the rod and a couple wire ties keep it in place on the extensions. I've since moved the computer up so it sits right between my hands which makes it very easy to view even when going all out.

Also spent time mitering the rod so it fits nicely between the extensions. Can use cheap PVC pipe for this or go nuts and get some carbon fiber tube. I'm tempted to epoxy the Garmin mount to the rod eliminating the rubber bands.

This was last year's set up but just to show the computer placement. I've since gone to Di2 (full internal wiring with battery in the seat post on the P3C) and just received the new 3T Brezza Nanos which will go on this week.


In terms of pacing strategies, there are some interesting studies on this. I tend to shoot for even pacing but there is an argument for shorter races that say a "U" shape pacing effort is faster and more natural. Hardest thing I had to learn was to not go too hard the first 5 minutes. Nice thing about TTs and a power meter - you can try many different variants and see what works best for you. Power never lies about your effort.

by Weenie


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Juanmoretime
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by Juanmoretime

A couple of more to add. Sunday was a two man 50K tt that it was raining with lightning and thunder during the race. It delayed the start and popped back up after we started. My partner popped after his first pull but we did well enough any way.

http://connect.garmin.com/activity/198045639

I also forgot to shut off my computer so our actual time was 1:13:07

Last nights shorty:
http://connect.garmin.com/activity/198045631

Two days after a 50K and a hot, humid night with a 16 mph northeast wind. I'll take it!
RESIDENT GRUMPY OLD MAN.

Machinenoise
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by Machinenoise

[quote="markc"][/quote]

"Noice" as we saw in blighty (UK) ! Random question how tall are you, looks like quite a small frame/ rider combo which is obviously an advantage, just interested being 6'1" and on a 56cm P3 with similar componentary, that i have to produce a significant amount more wattage to do a 57min 25 TT. However I do have local competition which can get by on 300w for 30mph average TTs.... :(

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grid256
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by grid256

However I do have local competition which can get by on 300w for 30mph average TTs....


Good gravy. Either I need to work on my position more or that course was mostly downhill. I averaged 316 watts in this weeks tt and clocked exactly 27mph. Many hills though.

Machinenoise
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by Machinenoise

grid256 wrote:
However I do have local competition which can get by on 300w for 30mph average TTs....


Good gravy. Either I need to work on my position more or that course was mostly downhill. I averaged 316 watts in this weeks tt and clocked exactly 27mph. Many hills though.


No, he's just a midget, ~5'4"

markc
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Joined: Thu May 17, 2007 2:23 am

by markc

Machinenoise wrote: "Noice" as we saw in blighty (UK) ! Random question how tall are you, looks like quite a small frame/ rider combo which is obviously an advantage, just interested being 6'1" and on a 56cm P3 with similar componentary, that i have to produce a significant amount more wattage to do a 57min 25 TT. However I do have local competition which can get by on 300w for 30mph average TTs.... :(


Apologies for the delay in responding, tnx for the compliment on the bike. 300w would get me to 30 mph too but I'm forever away from that power number.

Am 5'7" x 132 pounds (1.7M x 60kg) FTP is right around 255 and CP20 is 270. Figure with a little more work I can get those numbers up a few percent and run high 55 40K. Just another old guy riding a bike but it is fun.

Set up is a 51cm frame with a 35mm stem (DH Mtn bike stem). Had to go super short to get the pads where I wanted them. 30mm of risers. Rest of the bike is Di2 internalized, D/A wireless SRM, Stinger 9 front and Stinger Disk rear. RXLP tyres.


Updated photos with the 3T Brezza Nanos and Di2 shifters on the cow horns:

Image

Image

The Nanos are very narrow but not hard to ride at all. The short stem made the brake cable routing odd but works fine with the Nokons. Looks nice and clean from the front. Probably take this rig down to A2 in the late fall and see if we can tweak the position a bit, try some of the new helmets and maybe drop a few more grams of drag. It's a bit of an addiction at this point and I want that 55 min 40K badly :-)

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Juanmoretime
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by Juanmoretime

One more to add. It was a brutally hot night.

http://connect.garmin.com/activity/202878453

Heart rate readings when crazy after the turn around.
RESIDENT GRUMPY OLD MAN.

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Juanmoretime
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by Juanmoretime

Another tt and very hot night with a light wind.

http://connect.garmin.com/activity/208006726" onclick="window.open(this.href);return false;

Offical time was 24:26
RESIDENT GRUMPY OLD MAN.

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grid256
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by grid256

Ok, here are two recent races for me. As you can tell by the elevation chart the course is only flat at the start/finish area.

Link to race #7:
http://connect.garmin.com/activity/211071073" onclick="window.open(this.href);return false;

Link to race #8:
http://connect.garmin.com/activity/211068597" onclick="window.open(this.href);return false;

So... I'm left wondering... I smashed myself for race #8. It was the last of the series and I was determined to completely bury myself, which I did by riding an average of 21 watts higher than race #7. My time was however slower. I rode the exact same setup - wheels, skinsuit, helmet everything. One thing though - it started to downpour just after leaving the start line. Would the water on the road have slowed me this much even with the increase of 21 watts overall?

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Juanmoretime
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by Juanmoretime

All WAG's but was the wind speed and direction difference. Head wind direction for each race and velocity? With weather changes air density changes? I don't believe rain adds friction but different air density? Was your position somehow different?
RESIDENT GRUMPY OLD MAN.

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grid256
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by grid256

I'm not certain, but the wind speed between races was very similar. The air pressure however was likely different given the storm that rolled in.

After some thought I'm looking to my Quarq which I'm getting rid of. They're garbage if you have to a hard start as in a time trial. The rings slip ever so slightly against the round portion of the unit throwing the calibration off. I'm even running steel bolts with friction paste at 15nm and still getting the slip.

woz9683
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by woz9683

How did you compare to your competitition between the two?

Not sure how the falling rain effects you, but water on the road decreases Crr so you should actually be faster because of it (as long as the course isn't too technical, slowing you down in corners).

Other than the slipping you mentioned, the weather moving in could have caused a temperature drop which would have effected calibration as well.

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grid256
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by grid256

I beat my closest competitor on both races by nearly the same amount. Somewhere around 10 seconds on both races. After looking through some of my latest training files with 2x20s I'd say my earlier race had a power meter slip and my recent race in the rain was pretty dead on for my current fitness in terms of power numbers.

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Juanmoretime
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by Juanmoretime

RESIDENT GRUMPY OLD MAN.

mrlobber
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by mrlobber

Here is my first TT, using powermeter on the TT bike.
Dead flat, slightly wet course with quite low winds.

http://connect.garmin.com/activity/213735864" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Average watts lower than I hoped for (can push around 300 on a road bike for the same time), but I attribute this to the TT position, it might be my hip angle is too closed as I tried a new lower position recently.

Had a TT 2 months earlier in the same course (with more sidewinds and "old" - higher TT position), the speed and HR were basically similar as today.

What's more interesting - power is similar to Juanmoretime's previous post, however, speed is 2.5 km/h slower :|

Edit: putting into Chung model, it solved for CdA of 0.278

by Weenie


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