Never used power outside, but got a computrainer last year. looking to hit it hard this winter and trying to set some goals for next year. Im trying to get my IM bike split down from the 5:20:00-5:30:00 range down closer to 5:00:00. Wondering what kind of power that might translate to for both short and long computrainer rides (assuming an average IM course).
Too many variables to answer this. Mainly it will be dependent on your bike position, equipment choice etc on top of the basic w/kg.
jamie
maybe a easier question to start for anyone that done around a 5:00:00 split. what was your avg power? and what can you hold for a 10 mile tt or so?
Factoring in: bike position, course profile, wind, weight, road surface, tire and tube type, wheel type, helmet type, etc…
anywhere from 190 watts to 250 watts should do it.
There are just to many variables to say there’s one set wattage that will result in xx mph for speed. Do your testing, know your abilities, and, if possible, pre-ride the course to get an idea of what your power levels will equate to in terms of speed. However, speed is not a metric you want to look at on race day - way too many things effect it that may be out of your control, and focusing on hitting a target speed could be a recipe for going to hard on the bike and not having a great run.
I have a training partner who is 60kg and rides 5 hours on a flat course w/200 watts. I am 50kg and ride 5 hours at about 160! i dont know if there is some sort of calcualtion that can be done, but that is 40 watts difference for every 10 kgs… Do some testing and train with power for your long rides and 70.3’s.
This might help you:
http://bikecalculator.com/wattsUS.html
You can input the stuff you need to replicate your prior result, and then adjust the numbers to figure out your goal wattage. I hope that helps!
As several posters have noted, it rarely works well to say xx watts = xx speed. The biggest thing you can do if you want to get better is to establish a power threshold now and then make gains from it with the realization that a good IM ride ride falls roughly in the range of 65 to 75 percent of your critical power/FTP. Get that number up, with appropriate other training means go faster on race day. Chase the watts via your critical power and you’ll be riding faster and can execute a good IM.
A ton of variables as others indicated. But making a more educated guess it would help if you posted
- Your height and weight
- Your equipment. Bike, aero helmet, wheels utilizing, how you carry nutrition, how you care spare tire, etc
- Type of tires you are using and if clinchers type of inner tubes
- Ideally a picture of you in aero position. At least your amount of drop. Also percent of time you hold aero position
- What IM course you are targeting. St. George is very different than IMFL
A number between 190 and 250 was given. With the above info then we will be able to indicate if you would be closer to the 190 number or the 250.
Don’t train for a time, train for the biggest improvement you can get. Who knows that improvement might get you well under 5:00
Don’t put limits on improvement by setting finite goals. Use your IM time as a marker for your improvement, not as the improvement.
Assuming very good position & equipment and a flat course, I would say you want to get your FTP to 4W/kg or higher. Then you can try and ride the IM at ~3W/kg. I rode IMAZ last year in 5:14 on ~2.7W/kg NP in some wind. Targeting 3W/kg in a week and half at IMCoz and hope to be around 5hrs.
all good info. im around 3.75 w/kg on a 10 mile TT now, which got me to a 5:23:00 split on a flat course with challenging wind. think if i got that over 4, might have a shot at sub 5:20:00 for St George, given normal conditions. i try not to train for time, but i guess its just another way of saying i want to come off the bike top 10 or so in my age group.
I think you’re either severely underestimating the difficulty of that course, or overestimating what ~4watts/kg for 20 minutes will extrapolate to…
then i guess ill shoot for 5 w/kg…all i know is based on guys ive raced against that have done st george, i should be capable of around 5:30:00 today. i dont think shaving 10-15 minutes over the winter is an unreasonable goal, but if it is ill at least get a lot stronger trying.
all good info. im around 3.75 w/kg on a 10 mile TT now, which got me to a 5:23:00 split on a flat course with challenging wind. think if i got that over 4, might have a shot at sub 5:20:00 for St George, given normal conditions. i try not to train for time, but i guess its just another way of saying i want to come off the bike top 10 or so in my age group.
Curious - are you comparing FL to STG? If so, don’t! I’m not sure if you’ve done both but IMO you can add about 40 - 50 minutes to STG to compare to Fl 
Wow! 200 watts and under for an elite/pro road racer is an easy warm up! Could do that forever. You tri guys needs to ramp it up or join a touring group.
The key equation for power and speed is:
Watts - Drag/Resistance = Speed.
With:
Watts = your engine, which improves through training
Drag/Resistance = so many factors affect this and it is impossible to compare one person to another or one course to another. It could vary 50+% depending on how much you weigh, how aero your position is, elevation profile, and other little factors.
Speed = result of the equation.
As you can see the Drag/Resistance piece of the equation can vary a whole lot. As an example, if you actually assigned numbers to this - the Drag/Resistance could be either a “5” or a “1”. You are asking a question impossible to answer.
Not knowing your fitness, I would start at 2.5 watts/kg for an ironman length as a baseline and adjust as you get more data. Remember, the top pros are usually in the 3.5 to 3.75 watts/kg during ironman races.
So a 5:23 at Florida is the same as a 5:30 at St George in your book. I guess you’re just severely underestimating the difficulty of that course.
2011 - http://c28157.r57.cf1.rackcdn.com/2011/05/StGeorgeResultsBook.pdf
Ironman St. George **** Overall Results ****
Place No. Div Dnf Name Usa Sex Ctry Swim T-1 Bike T-2 Run Time Kona Qua
===== ==== ====== === ======================= === === ==== ======= ======= ======= ======= ======= ======= ========
1 15 MPRO Mathias Hecht 31 M CHE 49:16 1:48 4:42:32 1:39 2:56:50 8:32:03
2 4 MPRO Maik Twelsiek 31 M DEU 52:28 1:43 4:36:21 1:40 3:01:37 8:33:46
3 25 MPRO Tj Tollakson 31 M USA 49:18 1:35** 4:49:26** 2:00 2:58:02 8:40:20
4 2 MPRO Ben Hoffman 28 M USA 52:30 1:32** 4:41:49** 1:25 3:04:25 8:41:39
5 6 MPRO Mike Aigroz 33 M CHE 49:31 1:56 4:49:34 1:31 2:59:36 8:42:06
6 7 MPRO Paul Ambrose 27 M GBR 49:09 1:51 4:45:02 1:42 3:13:59 8:51:41
7 22 MPRO Alejandro Santamaria 34 M ESP 56:55 1:46 4:58:36 1:28 3:05:56 9:04:38
8 8 MPRO Christian Brader 31 M DEU 57:31 1:29 5:02:17 1:51 3:05:14 9:08:19
9 5 MPRO Petr Vabrousek 38 M CZE 56:51 7:26 4:57:11 2:06 3:07:39 9:11:11
10 19 MPRO Bevan McKinnon 40 M NZL 54:24 2:00 5:00:01 ** 2:43 3:13:31 9:12:37
11 20 MPRO Ernst Moser 32 M AUT 57:28 2:21 5:01:28 1:25 3:11:55 9:14:35
12 929 M35-39 Fabrice Houzelle 37 M FRA 1:01:21 3:29 5:08:08 2:10 3:11:03 9:26:09 X
13 18 MPRO Joe McDaniel 29 M USA 52:28 2:01 5:04:51 ** 1:53 3:25:17 9:26:27
14 809 M35-39 Maximiliano Morales 35 M ARG 55:11 2:02 5:17:09 2:16 3:13:49 9:30:25
15 36 FPRO Heather Wurtele 32 F CAN 55:00 1:50 5:17:00 1:54 3:14:51 9:30:33
16 1248 M40-44 Chris Hauth 42 M USA 50:43 2:19 5:16:38 4:27 3:17:50 9:31:56
17 958 M35-39 Edward McDevitt 37 M USA 1:01:00 3:14 5:09:55 ** 2:38 3:15:40 9:32:25 X
18 798 M30-34 Spencer Woolston 34 M USA 1:04:17 2:38 4:58:09 1:48 3:26:26 9:33:16
19 689 M30-34 Trevor Glavin 32 M USA 55:16 2:53 5:16:08 2:09 3:17:39 9:34:05 X
20 564 M25-29 David Lebrat 29 M FRA 58:47 4:44 5:06:58 3:52 3:19:58 9:34:17 X
21 26 MPRO Luke Way 29 M CAN 59:40 2:16 5:17:13** 1:57 3:13:47 9:34:50
22 700 M30-34 Ben Cotter 32 M CAN 56:01 3:23 5:09:16 1:38 3:25:30 9:35:46 X
23 493 M25-29 Adam Bohach 27 M USA 58:10 3:42 5:12:29 ** 2:19 3:20:12 9:36:50 X
24 10 MPRO Bruno Clerbout 35 M BEL 52:32 1:37 5:09:40 2:58 3:30:26 9:37:12
25 738 M30-34 Nick Goodman 33 M USA 59:17 2:46 5:07:39 2:10 3:26:19 9:38:08 X
26 1040 M35-39 Declan Doyle 38 M IRL 1:01:45 2:45 5:08:15** 1:57 3:26:24 9:41:05 X
27 704 M30-34 Pablo Ureta 32 M CHE 56:04 2:21 5:14:13 2:06 3:26:37 9:41:20
28 1930 M30-34 B.J. Christenson 33 M USA 56:05 2:05 5:35:57 2:27 3:12:16 9:48:49 X
29 1291 M40-44 Stefan Kusurelis 42 M USA 1:02:21 3:36** 5:11:18** 2:38 3:30:23 9:50:14 X
30 1928 M30-34 Thomas Gerlach 30 M USA 58:39 3:13** 5:21:24 ** 2:14 3:29:56 9:55:23
31 568 M30-34 Benjamin Winterroth 30 M USA 56:46 2:47 5:23:15 ** 1:48 3:31:08 9:55:43 X
32 626 M30-34 Brandon Mills 31 M USA 1:07:18 2:30 5:16:51 1:27 3:27:54 9:55:59
33 1195 M40-44 Jared Preston 41 M USA 1:03:36 2:39 5:07:25 1:58 3:41:43 9:57:19 X
34 836 M35-39 James Peet 35 M GBR 1:04:39 2:46 5:16:25 3:06 3:31:03 9:57:57 X
35 12 MPRO Scott Defilippis 31 M USA 59:37 2:10 5:20:04 4:55 3:31:21 9:58:05
36 560 M25-29 Mark Villwock 29 M USA 1:02:47 2:59 5:08:44 ** 3:09 3:40:35 9:58:11
37 915 M35-39 Lee Hunt 36 M USA 1:10:31 3:34 5:12:30 3:30 3:28:34 9:58:37 X
38 1342 M40-44 Marcel Hotz 43 M CHE 1:07:59 3:57 5:17:22 2:00 3:28:20 9:59:36 X
39 1356 M40-44 Jeff Shilt 43 M USA 1:04:18 1:59 5:22:53 1:54 3:29:23 10:00:25 X
40 819 M35-39 Pablo Rodriguez 35 M ESP 57:37 2:56 5:19:18 6:19 3:34:47 10:00:55 X
41 486 M25-29 Derek Garcia 27 M USA 57:05 2:23 5:18:19 2:27 3:41:02 10:01:13 X
42 920 M35-39 Stefan Irion 37 M USA 1:03:35 2:50** 5:20:49** 1:42 3:32:27 10:01:21 X
43 1115 M35-39 Randy Stueve 39 M USA 1:03:52 3:18 5:31:12 4:05 3:20:42 10:03:08 X
44 713 M30-34 Matthew Porta 33 M AUS 59:26 4:04 5:32:14 3:48 3:24:54 10:04:24
45 1565 M45-49 Roger Canham 47 M GBR 1:06:11 3:03** 5:24:56** 2:21 3:29:47 10:06:17 X
Wow! 200 watts and under for an elite/pro road racer is an easy warm up! Could do that forever. You tri guys needs to ramp it up or join a touring group.
Well, doing it for 112 miles is basically forever. Then running a marathon. Don’t forget about that little nugget.
wow, sorry i posted a time goal. guess ill keep those to myself. but no, that wasnt florida i was referencing. and i dont think st george is much tougher than louisville and i was 5:30:00 there, top times are virtually the same. dont hate on a guy for setting a goal…
Relax, I’m not hating. Louisville - at least among the pros - was a much less competitive race than St George.
One of the best things I did this year was take away all time goals on the bike (at least for the first long course race) and ride solely by watts. No MPH on the computer, just watts and time. That way, the bike split is what it is.