Any relationship between watts/kg and IM bike split?
I know that watts alone can't tell you much about your IM bike split, but what about watts/kg? I would truly love to get in the neighbourhood of a 6 hour bike at IM Canada this summer. Any of you who have done this race, do you know roughly what your watts/kg was for your given bike split? It would be nice to have some kind of target to work towards.
Thanks for any input!
---Ann.
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I'm not aware of any published or data-driven correlations between the two, but W/kg is a good predictor of performance at many standard distances. It may be out there but I've just never come across it. The IM is tricky because it's a bit longer than most one-day non-stage races, and there are additional endurance considerations and race execution factors that come into play. Keep in mind that W/kg is typically defined by your mass-specific FTP (i.e. your 1-hour TT power). Other important considerations that parallel W/kg are bike position and gear selection (helmet, tires, bike setup). Any resistance (such as aerodynamic drag or rolling resistance) will effectively diminish the value of your W/kg.
Conceptually though it makes sense that it's better to have a higher w/kg and vDot than your competitors.
I was 5:24 at 4.0w/kg.
Also, http://www.analyticcycling.com -> Static Forces on Rider -> Speed, Given Power
---Ann.
Watts per kilo is very important as the road tilts up. The actual watts though propel you down the road. A lil peep at 4.0w/kg will not out split 180lb doode with 4.0 watts per kilo as well. He is just putting out a lot more power. Average power would be a better predictor (but not much). Average power + weight of rider even better.
You can use analytic cycling to run some 'what ifs' but watts per coefficient of drag is critical for time trialing which is why we but some emphasis on 1. Getting a strong as you can. 2. Get as lean as you can. 3. Extract as much speed our your equipment/position.
Ann , I see while I Ws writing this Dave posted his data – so here is my 2 cents.
I'm going to go over and play with those two calculators. Again, you all have been so helpful. I really appreciate being able to pick your brains!
---Ann.
Beverly Excellent Idea.
There is so much data from people on this site, I am amazed. Putting it to work like this would be a terrific resource!
---Ann.
kickin' it EN old school - see the original sheet here.
Sorry - I see on the google sheet that you have to request access from some doode named Patrick McCrann.
Or that doode could be asked to make access public so the world can see the doc.
But it's a spreadsheet that includes essentially what has been proposed, with ~30 IM entries, HIM entries, FTP, w/kg, bike split, run split, pace, etc. (Actually, it might be something that R and P would prefer to keep proprietary, so i should shut my mouth).
Here's a somewhat related thread:
Craig – Totally agree that W/CDA is the real indicator to how fast you will get around a course. I have see multiple approaches to estimate CDA ( roll down test for example). Do you know of an approach that we could adopt as best practice? For now we can put a place holder column in the sheet for data to be captured later.
Matt
Craig, your experience at IMC sounds bad - freezing rain and those descents?? Geez, Louise! I summer out there every year, I know that course, and coming off Yellow Lake in that crap makes me feel sick. I am also a chicken on the descents! Probably should work on that too -not just my w/kg! Ha!
Thanks again for all the input. Really helpful stuff all!
---Ann.
@Matt: The short answer is Aerolab, the longer answer is "there's still no short answer".
But that reminds me that I have an email sitting in my draft folder addressed to AndyF (the Golden Cheetah Aerolab guy) that I'll finally dust off and send - who knows, maybe it'll get easier soon rather than later.
Thanks Matt for driving this!
FWIW, in the days before I had a Power meter (01 & 02), I did that course in 5:45 with what I estimate was 3.3 or 3.4 w/kg. But I had not yet learned proper pacing EN style, and so walked 6-8 miles of the run, going about 5:15 instead of the 4:10 or so I was capable of.
Take a course like Placid, with the long downhill of 7 mi. If you ride that at goal watts, you could easily be doing 45+ mph, which some people are comfortable with, others are not. If you are only comfortable doing 30 mph, that is a difference of 7 minutes (across two laps).
You might say "well, that should show up in the VI", but really, it might make a difference between 1.02 and 1.03, which could also be made up by a stop to pee, a few times sitting up to avoid drafting, or a couple of inadvertent surges on a hill (none of which would make a 7 minute difference in your time).
So, maximizing your performance is a function of maximizing your watts, and then optimizing 'how you use them'. There are times where you can spend a few watts and make a big difference, and other times where it makes no difference (ie. Cresting a hill vs. At the bottom of a hill). Learning how to get the most speed out of your watts is a skill unto itself.
Howdy.
more data.
Did Canada 2010.
bike 5:52
run 3:51.
Wasn't doing power then. Am now. I believe I'm a stronger biker now.
I weigh 185 lbs.
Thanks for sending me the link to the chart. You appear to be a perfect example of riding your watts well, and you ran really well to boot. What did you do? Stay aero, not stop to pee, etc? Bike/wheel setup?
Ok – I have a first pass at creating a race database spreadsheet. To keep the number of TABs to a manageable level we can have one for full IM’s and one for 1/2 IM’s.
I'm not sure we/you have such data to conclude anything meaningful on the above.
@ Matt - Splits do exist in a single file, although I don't know if it is in a format which is accessible to data mining.
On the standard IM results page, at the very bottom, splits for six IMs (AZ, CDA, FL, WI, Utah (the original, 2003), and LP) and six 70.3s are available in funky drop-down menus. They only go thru 2009, except WI, which goes thru 2008. And of course, there is no standard length for the run splits - just recording wherever the mat is placed, which varies from race to race.