IM Course @ xxx power = X:XX:XXX

triguy44

Is there a resource that has some data relating to each IM course saying that if for example you ride IM AZ at 200w you will finish the bike leg in about X:XX:XX?  Looking for a power to time ratio for certain courses...

Thanks.

Carlo_Tangonan

Interested in this as well. For pretty flat courses, http://bikecalculator.com/veloUS.html was pretty close when I did Racine 70.3 and IMFL. In my case, I want to find out what a 5:10 time in IMFL would equate to at IMWI.

Steve West

I am looking for the same info except for Lake Placid. I started a tread to collect data and have been messing around with some of it here

http://members.endurancenation.us/Forums/tabid/57/aft/10915/Default.aspx

Coach Rich

In my experience, these exercises are interesting thought experiments but don't really yield much useful information. That is, between the variables of power output, equipment selection, bike fit, wind conditions, temperature and much, much more, it's very difficult to say that watts x = time y on course z. And, you can't really use that information for any purpose, other than to dream about bike splits?

In the end:

• Show up as strong and light as you can.
• Achieve an excellent bike fit
• Pay attention to small details like bottle setup, gearing, wheels, aerohelmets, etc
• Ride "smartly," at appropriate IF and good VI

Bike split then sorts itself out.

Carlo_Tangonan

Posted By Rich Strauss on 05 Mar 2013 10:26 AM

In my experience, these exercises are interesting thought experiments but don't really yield much useful information. That is, between the variables of power output, equipment selection, bike fit, wind conditions, temperature and much, much more, it's very difficult to say that watts x = time y on course z. And, you can't really use that information for any purpose, other than to dream about bike splits?

In the end:

• Show up as strong and light as you can.
• Achieve an excellent bike fit
• Pay attention to small details like bottle setup, gearing, wheels, aerohelmets, etc
• Ride "smartly," at appropriate IF and good VI

Bike split then sorts itself out.

LIKE!!!

zwuba

Well basically as all IM courses have start and finish on the same point in actually makes no difference if it's a hilly course or not - you just take your average power and that's it.
The best calculator I know by far is this one -> http://www.kreuzotter.de/english/espeed.htm
Be aware that for round-courses the slope of the road is always 0 because the number of meters you have to climb equals the number of meters you will then decend again!

BUT (and that's a big BUT) ... as Coach R stated there are so many more factors that massivly impact your bike split (especially wind and your CdA!!).

What I would do is to approximate your CdA using GoldenCheeta (Chung method) than you could basically get better results out of that calculators ...

John Withrow

Stefan, I must respectfully disagree. Flat courses are certainly faster than hilly courses, especially for bigger peeps.



Imagine if you had a net 10,000' of uphill for 100 miles straight, then a REALLY steep 12 mile downhill section that started and ended at the same point so zero net gain. Now compare this to a perfectly flat course for 112 miles. In the 2nd "flat" scenario, you might be done with your whole 112 miles in 5:00:00 flat. On the course that is net 10,000' uphill for the first 100 miles, you might not even make it to the peak of the hill in 5:30:00, and you'd already be off of the other course... Because you are spending so much more "time" going uphill than downhill, the net incline or decline being 0 total feet is almost irrelevant. Now take that extreme thought experiment and extrapolate it onto real world courses... Hilly courses (especially ones that don't allow you to carry your downhill speed and momentum up and over the next hill will be slower than flat courses for the same W/Kg. W/Hg is very important on hilly courses, but on flat courses, total overall Watts are more important than W/Kg.

This doesn't even take into account CdA, Wind, IF, cornering ability, bike handling, brake usage, pee breaks, aid station slowing, etc, etc, etc...

x3 on what Coach Rich said...

Al Truscott

Anxious/curious about what your bike split might be on IM race day? In my experience, the best predictor is your EN race rehearsal 3 weeks before. If you successfully complete the 1 hour run after that, you can expect to ride about 10 minutes faster, given the same environmental (temperature) conditions on race day.

Looking to maximize your potential on race day? - do what Rich said, with particular emphasis on aerodynamics (especially head position) and VI (keep it LOW, meaning ride at a steady effort level, irrepsective of gradient, wind, etc.)

Michael Byerts

I think this question comes up because the time/tss table for IM and HIM racing requires you to estimate your bike split to enter the table. If you haven't done a ironman or a half-ironman before, or you are new to training with power, you simply may not know whether 200 watts will get you off the Arizona course in under 5 hours 20 minutes or whether you should plan to be out there for 6 hours. As a result, trying to plan your race rehearsals and race plan can be simply guesswork, especially if the first rehearsal doesn't go well.

So, I think it would be helpful if we had some very rough guidance along the lines of X watts and/or Y watts/kg will complete a HIM/IM course in about Z time, assuming an average wind/tempature day, reasonably good bike setup and reasonably well executed bike.

Here's my data point (your results may vary): 200 watts and 2.3 w/kg got me around an average 70.3 bike course in just under 2 hours 35 minutes.

Cary Blanco

I completely agree with what Rich and Al said.

GMAN 19030

Posted By John Withrow on 05 Mar 2013 02:58 PM


Stefan, I must respectfully disagree. Flat courses are certainly faster than hilly courses, especially for bigger peeps.



Imagine if you had a net 10,000' of uphill for 100 miles straight, then a REALLY steep 12 mile downhill section that started and ended at the same point so zero net gain. Now compare this to a perfectly flat course for 112 miles. In the 2nd "flat" scenario, you might be done with your whole 112 miles in 5:00:00 flat. On the course that is net 10,000' uphill for the first 100 miles, you might not even make it to the peak of the hill in 5:30:00, and you'd already be off of the other course... Because you are spending so much more "time" going uphill than downhill, the net incline or decline being 0 total feet is almost irrelevant. Now take that extreme thought experiment and extrapolate it onto real world courses... Hilly courses (especially ones that don't allow you to carry your downhill speed and momentum up and over the next hill will be slower than flat courses for the same W/Kg. W/Hg is very important on hilly courses, but on flat courses, total overall Watts are more important than W/Kg.

This doesn't even take into account CdA, Wind, IF, cornering ability, bike handling, brake usage, pee breaks, aid station slowing, etc, etc, etc...

x3 on what Coach Rich said...

In all fairness to Stefan... you're debating a point he never made.  He simply said to ride your power numbers and made no mention of time or speed.

John Withrow

The initial question in this thread was about a bike split for a given power...  And the link to the calculator Stefan dropped in (and a super cool calculator IMO) was to calculate an average speed for a given power and with a known weight of a rider and bike, etc.  The calculator requires you to put in a slope of road as well.  Just because the total meters you climb equals the total meters you fall, doesn't mean that your slope should be 0 for the whole ride, because the slope determines predicted speed and total speed will actually be different for the entire ride if there are many different segments of different positive and negative slopes. 

So it was these to parts that surrounded Stefan's calculator link that I was specifically responding to (and I had no intention of offending anyone, simply wanted to further the geeketry on my part):

"Well basically as all IM courses have start and finish on the same point in actually makes no difference if it's a hilly course or not - you just take your average power and that's it." 

"Be aware that for round-courses the slope of the road is always 0 because the number of meters you have to climb equals the number of meters you will then decend again!"

In my crazy example you would need to use a 1.736% Slope for the first 100 miles, and then a -14.70% for the remaining 12miles.  So for a 188lb rider who is 73 inches tall and raced at 200W in 78 degree weather, the calculator would predict a 21.4mph speed or a 5:14 bike split (I raced IMFL last yr with roughly those parameters and hit a 5:04 bike split, so pretty darn good calculator actually).  However if you used the different slopes for the different sections of my fake hypothetically extreme course the calculator would predict 15.4mph for the first 100 miles and 61.7mph for the last 12 miles for a total time of a ~6:41 bike split.

So I did think that he was implying that you could simply use a 0 slope for any loop IM course to predict your expected finish time, and I wanted to clarify that this is incorrect.  I wasn't meaning to offend anyone, simply geeking out over these cool calculators and my engineering brain started to take over.  To really do it right using one of these calculators, you would need the actual slope for many many segments of the course and daisy chain them all together to model the actual course.  I think this is a simplified version of what the computrainer software actually does when you ride one of the IM courses and it is telling you your speed at different points and average for the total ride. 

The important thing that I think everyone mentioned above is to get your fitness as high as possible and your weight as low as possible going into the RR's.  If you don't know where to start the circular reference on the TSS charts, just use an IF of 0.70 for your first RR and see the time and how you run afterwards, and use those result to modify your IF for the 2nd RR.  I also agree with Al that your real bike split is likely to be 10-15 mins faster than your best successful RR, so use that number to put into the TSS chart and you'll be close enough for all controllable purposes. Oh yeah, and also maximize your speed on race day by getting a super aero bike setup, always staying in the aerobars, and never, never hitting your brakes!

tim cronk

There are just too many variables. Its nice to give you an idea but in the end, X-whatever on what Rich said , ride your watts , let the time sort itself out.

2 years ago I rode Mooseman 70.5 (extremely hilly) in 3:05 . Last year , bumped up FTP just a couple watts and I was consistently training the course under 3 hrs.... Race day I rode 5 watts higher than previous year and ended up with 3:10 (wind and rain) I fully expected to ride a 2:50......

Last summer I rode an out and back course of 30miles X2 for my ABP 60mile rides. The EXACT same wattage yielded average speeds between 20.5 - 23.5 . This on an out and back x2 course you would think that any hills or winds would cancel themselves out. Huge differences at the exact same wattage.

zwuba

Everything said here is true so no need to get into an endless discussion



As everyone agrees Aerodynamics goes over Weight when it comes to TT biking we should all agree that keeping an eye on that is for sure worth it.

W/kg is a nice metric especially when you are going a lot uphills but for TT biking (which by its nature is done mostly in flats) W/Cda is a much better one (that was the reason why Rominger was faster than Indurain) ... but all that metrics are nothing more than metrics .... it's just a value.

I'll give you an example from my personal experience:

I KNOW (because I've seen the power data) that the a guy with comparable height and weight like me did the IM-Austria 2010 bike course in exactly 5:01:43 putting out an average of only 196Watt.

Now that information is nice to have but in the real world everything could be totally different this year so I give a s*$t on it and just try to be as fit and as aero on the bike as I could possibly be on race day and the rest will be a story told by the race itself! 

 

BTW: The main reason why I mentioned that Cda - Chung method thing is that this is something you can VERY easily do by yourself to tune your aeroposition having a metric that tells you if some changes gave you any benefit or not.

Checkout this site if you are interested in more info here -> http://www.cyclingpowerlab.com/

Coach Rich

Likewise, I have a lot of personal historical data about what watts yields what time for me on the Ironman Wisconsin course. 3x races, numerous RRs on the course, etc. I have the same data for Wildflower and Oceanside. 

But I wouldn't feel confident extrapolating that data to anyone else even on those same courses. I can say "216w Pnorm gets me a 5:11-12 on the over-long IMWI'11 course" but that's about it. 

Bob Irwin

I asked this a couple of years ago, and got pretty much the same answer. So many variables, so hard to answer. I was getting ready for the full Vineman (not all IM distance races have a single transition by the way), and knew that I had an extra 15 watts, and 10 fewer pounds. I was trying to figure out my time for the TSS calculator several months out from the race. Rich told me I was thinking too much about it too far from the race. What Al said turned out to be absolutely true - the second race rehearsal was the best predictor.

rbogle

Agree with the vets about your RR being the best predictor. And of course the more you pay attention to aero and friction the faster you can be. 

But if you want to play with numbers along the way and dream...( I do this a lot ), I found this calculator is a pretty good estimator for performance: http://www.triathloncalculator.com Take it with a grain of salt. 

Its been dead nuts on my IM AZ (though thats probably not a hard one to predict) and pretty darn close on some other 70.3 races I've done.

Carl

Ride YOUR watts only!! Simple. .7-.75 intensity on the long course. Get way light and stay strong and have the proper gearing for the course.

John Withrow

@Rian- that calculator is scary... I put in all my data from IMFL From last yr and I beat the predicted swim time by 5mins, and the predicted bike time by 3 mins and beat the run time by 4 mins... Overall, I beat the calculator by 10 mins, but that was crazy accurate for my n=1.

For IMNYC last yr, the swim is irrelevant, but I beat the bike time by 5 mins and was slower on the run by 1 min!!!

So I couldn't help myself, I went back to IMLou 2011 and input that data... I beat the bike and run by about 10 mins each.

In each case I gave myself an extra 2 yrs experience than I really had because I figured that was my EN execution ninja advantage...

That's a pretty fun toy. Now off to see how fast I'm gonna do IMUSA this yr... Just kidding!

rbogle

@John, yeah its pretty interesting. QT2 systems must be very data focused to have built that model. They have a very similar training and execution philosophy to EN it seems. 

Funny you and I both did the same thing bumping up years of experience. I had forgotten about that!

Pina

Message is loud and clear! Focus on Process and the outcome takes care of itself. Focus on Outcome = : (