SBR Utopia - OPEN (Page 153)

It can be really difficult (if not impossible) to stay within power zones on hilly courses.  My target power for IMMT was 175 but on many of the hills I had to go over 300 just to avoid tipping over.    However, on other hills where I could manage, it was great for keeping me from being too aggressive on some hills.  It can be REALLY hard to cruise up a hill and have a boatload of people passing you.  The first loop around I quickly discovered that I would repass many of those same people as they coasted and tried to recover on the descents. 

To add to it, it's "just" an Oly which, in my mind, is less about moderating power than going blls to the wll for as long as you can until you blow up.  On top of that, the first mile is basicaly steep and uphill, so I imagine I will be well over 300 for the first several minutes off the swim

If they could do that from the car, and make decisions that way...that would be amazing.  Something tells me it would be a little bit of information overload, but if there was ever a sport where they would take the time to do it, cycling would be it.  Power and HR doesn't measure the gut and will of a rider though.  I can't remember which stage race it was last year, but Jens Voigt went on some crazy suicide solo break from the first 10 miles of the race and held everyone off.  I remember the team director in the car following him the last 20 miles or so.  I don't think he was monitoring his power or HR...just yelling in his ear that he could do it.

Sort of hard to see, and it's not a side view, but here you can see how the bottle is hidden behind my hands (using the A2).  And to answer the question, when I use a regular bottle instead of the A2 it is not hard to remove and replace while in aero (well, one arm at least)

(California2013.jpg)

too small, better pic

(Oceanside.jpg)

Well, short course is still about moderating power, it's just at a higher level than long course. If it's messed up on long course, the length of time really suffering goes up quite a bit more. And we forget that the run is going to hurt anyway. We're also expecting to hurt a lot on the short course, so may not recognize pacing issues as well.

Last year I felt more likely to pace a long course fairly well without metrics, and actually did ok with that on one I needed to. Short course also doesn't carry the same fear of not making it around or that it's a long way to go, especially when we've done long course.

The straw is still up, tsk tsk.

That was awesome to watch.  "Shut up legs" in action...

Good blog post on weight v. aero

http://fiftyonespeedshop.com/post.php?id=62

ZOOM - that just looks fast!  Except for the straw, of course.

Follow up question.  I have a Garmin 800 that I use on my road bike and really like.  I also have a 910xt that I use swimming and running.  I am considering a tri bike (as in, gonna buy one SOON).  By now, you're wondering what the question is, I'm sure...

So, to put a bottle in aero and get data from a PM and/or GPS/cadence sensor (depending on how long it takes me to plunk down for a second PM), would it be better to ride with my watch turned "inward" on my wrist (which is easy enough to see in aero) and put the bottle a tiny bit more centered/forward, or jack the bottle back a bit and keep the 800 in the cockpit?

Thoughts?  Not sure there's a huge difference, but I'm very happily pondering all the silly stuff I can do once I buy a tri-bike!

Thanks,

Matt

Very interesting read (although it makes me want think I can compensate for an extra bit of ice cream with a disc wheel - not the intended outcome, methinks!).

I wonder at what point in fitting a bike does aero trump ideal geometry for power production.  Relatedly, at what point does position for aero compromise the ability to run off the bike more than it saves W?

I realize that this is testable for each person with a power meter, wind tunnel and bike fitter on hand for a few hours, but wonder if it's been done/tested/written about.  Any even general heuristics out there?

Apologies if this is total old hat, but I'm just getting to what are, to me, some of the finer points of triathlon (rather than just working on going from a 2 cylinder engine to, well, hopefully something more powerful!).

Thanks

Matt

I use the profile design universal computer mount, and put it way up front on my aero bars.  So much so, that I had to undo the bar tape on the extensions to mount it, then rewrap the tape around the mount.  The leading edge of my 500 ends up about even with the end of the extensions right where the shifters are mounted.  This actually gives me a much better viewing angle, and also leave lots of room behind for me to mount my bottle between the bars.

I wish I could find the article, but there was stuff written about this when LA got into the tri thing and worked with John Cobb in the wind tunnel. They found a compromise of going low in the front and shortening his cranks to find that balance of power production. And while he did improve his position, he was not as slammed as some of the other guys.

It is hard to test. How do you test the ability to generate power ? Do you make him do a 20' power test, change his position, do a 20' test ? Do you look at his HR at a given power level ? Do you go by RPE ? They all have their flaws.

As an ex clyde I do like the way you think

Back when I was a scientist instead of just pretending every once in a while, we'd just do all three (or more) methods.  In triplicate.  As long as we had grant funding. 

I think it is very difficult to replicate exactly with different setups, which makes it all seem like a fair bit of art involved. 

A LBS here claims to have analyzed the data from hundreds of fits (I forget the name of the iron horse system they have, but they also have the little sticky dot laser system on a CT or the like with power).  He claims that for the first few mm of change in position, you get a 6W difference per mm.

Not sure I believe that one, mind you, as he's also selling a product (mostly himself, which he then leverages to sell $10k-$20k bikes - just an unreal amount of PRICEY bikes roll out his door)...

I was just wondering if anyone had seen anything similar, or some general guidelines.

I'll poke around and see if I can find the LA stuff.  Thanks!

Matt

You should check out what these guys are doing at Ero Fit here at our AEG velodrome

http://ero-sports.com/index.php/component/content/article?id=%2042

There was a recent ST thread on it, but basically real time wind tunnel analysis while you ride (i guess) the track). 

I am going for a fit with these guys in June, so maybe I'll learn more (not the wind tunnel stuff), and I'll ask about the straw (actually that last bit is serious, I am curious as to their opinion)

From Xlab's website

A 3/8 inch diameter straw alone generates around 50 grams of drag over 25 mph.

So it slows me down going down hill

How do you quanitfy 50g of drag? It is a rare occasion, if ever, I am doing 25 mph on the flats.  that would also have to be compared to the drag caused by me moving my arm to untuck/retuck the straw

If you're testing ability to generate power, then yeah, you need a 20' test at threshold.

A simple CdA test, though, you can ride, say 5 mins at a fixed power level and see what your average speed was.  Or flip it around: ride 5 mins at 20mph (or whatever) and check your average power.  Preferably in a velodrome or non-windy, flat out-and-back.

There's more detail in Training and Racing with a Power Meter, pg. 249-252ish.

Also a useful link:

http://www.cyclingpowerlab.com/CdAEstimation.aspx

/end geek

that was invented by a guy from Montreal. Super nice guy, who is a friend of friends.

they only test at a single yaw angle so does not give the full picture, especially if you want to test hydration and helmet setups.

There are also some formulas you can use that will give you both your Crr and Cda. You need to test at various power levels. So for example I go to the F1 track, do a loop at 140watts, another at 160.....280.

You plot velocity and power taking into account air density and it poops out a Crr and Cda

50g drag = 5 w = .5s/km so....on a HIM 45sec

Thanks

That's all else being equal.  Now, take away the :45 and add the time as noted to bring my arm out of aero, pull out straw, back in aero, drink, pull arm up, stow straw.  I'd bet it's a wash or faster with the straw up?

At any rate, unless I am seconds out of Vegas qualifications, I'm not going to worry much about that aero penalty, but it is interesting to know what that theoretical penalty is in real world terms