Ok, after about a month of active use with my new powertap, it’s become very apparent that i can climb at a much higher average power then i can ride in the TT position. I practice quite a bit on the trainer and in the aero position, so i’m not really sure why this is. I’m concerned about this, if i could somehow translate the power i can produce while climbing into something similar in the aerobars my bike split it a tri would improve drastically.
For example:
a hard 10 minute interval in the aerobars:
avg HR: 178, avg power: 268 watts
a medium hard climb (it took me 10:50 to complete, my PR on this climb is around 9:40)
avg HR: 175, avg PWR: 319 watts
I’m not exactly a skinny little mountain climber either. about 159lbs and under 6ft tall (about 4 lbs overweight right now though)
Any ideas on what i can do to help translate some of that climbing power into TT power?
very good question. interested in what others have to say.
I don’t own a PT yet but plan on purchasing one soon. I TT in a lab before and realized that, for me, it was much easier to maintain a higher power output by pushing big gears compared to increasing the RPMs. Average of 82 was the cadence of my best TT which lasted 47min.
maybe you can have a session or two a week focusing on pushing big gears. what were the readings in RPM when climbing compared to TT on the flat?
Assuming that your climbing position is done with your thigh-to-torso angle much greater, there’s your answer…that position is more powerful (and it’s easier to breathe!). The problem with this in the TT is that it’s so bad aerodynamically. That is one reason steep seat tubes work for TT’s…you’re trying to get as low and aero as possible while maintaining a favorable thigh-to-torso angle. At least, this is part of the reason…
Very interesting. I seem to be finding the opposite on my CompuTrainer. I can produce more power with a lower heart rate when I am up on the outside bars than when I am over on the aerobars. I try to keep the same heart rate when leaned over but I can’t seem to produce the same power. When I am up I know that my lungs are open = more Oxygen or should I say easier to breath. I guess I just have to do more work in the aero position.
Good question. As has been stated, the climbing position is more powerful but woefully non-aero. The trick to finding your best TT position is to find your “happy place.” You’re going to sacrafice power in the TT position for less drag but, in my opinion, 50 watts is too much. Perhaps you’re too low right now, and you need a position change. Everybody is obsessed with getting as low as possible, but it’s not always the answer. Training (as far as training your body to go low, or “earning it” as Gerard recently said), body composition, and the length of time you’ll be required to hold your TT position are all factors which should play into your positioning. I find it interesting when someone goes super low up front, but can’t hold the position for any length of time. They ending moving around all over their bike and lose all the aero benefits they believe they’re gaining. A less extreme position would be more beneficial because the rider is capable of staying in such a position for a longer period of time thereby taking better advantage of the aerodynamic benfits. Okay, I’m drifting a little, but the point is, your position seems to be off a bit. You’d be well served to use that power meter to try different positions on the bike to see which might have the best of both worlds - aero and powerful. I’d recommend doing something like this with an experienced coach. Alright, my kids are climbing all over me right now, so I have nothing further to offer. Good luck!
I must admit the same experience, despite many efforts to close the gap and disprove the notion that we can climb more powerfully than we can TT.
I have two reasons for the gap (10 minute TT = 265 watts; 10 minute climb = 280 watts). One, I am more powerful if I sit up as straight as I can. There is no need to do that when TT’ng because the extra power is lost to the wind. If I could race with no wind resistance, I’d sit straight up all the time. So, when I climb, I open up the thigh-torso angle as wide as possible by sitting up high.
Two, the lower gearing in climbing allows me to put out more power before fatigue-ing out. Don’t know why exactly, but it seems to work that way.
All of the replies to date seem to have focussed on the leg/torso angle. However, if you climb on your aero bars you will experience exactly the same thing (i.e. more power climbing compared to riding on the flat). So whilst the hip angle answer is valid, it is not the only thing that is happening here.
People who are much smarter than me say it is to do with your ability to apply force against a crank having different inertial loadings (on the flat, high speed = high inertia…on the hills, low speed = low inertia).
OB, good point about the inertial effect. In a high gear at a high speed, you don’t have to push down hard for the pedal to continue to go around at the same rpm as it was (at least for a few strokes)same is true when you DO push harder…it takes a few strokes to see an rpm change. IOW, it takes a little while to change rpms, or it takes a relatively large change in power from stroke to stroke to change the rpms. In a small gear it takes a smaller change in power to effect a change in rpms…another way to say it might be your lever arm acts as if it is longer in the smaller gears, or you have more torque. Maybe this difference in inertia shows up as an increase in power on the climbs due to the biomechanical qualities of our musclular-skeletal system. A way to know if this is true is to test a small motor…see what power it generates on the flats in a big gear, start to go uphill and change the gearing appropriately to see if the power is higher going uphill compared to on the flat. I would assume the power is going to stay constant (assuming the motor was at it’s limit in both cases). But we don’t pedal like a motor, we have piston-like movements going on, complete with intramuscular drag forces, peak and valley power outputs of each piston, changing breathing/venous blood return patterns, recruitment and de-cruitment (is that a word?) of muscle bundles, etc.
Perhaps another thing is that the rpms aren’t the same between the two styles…that can affect power, too. Pedal too slow, and you run out of gas, although you can be powerful for a while. Too high, and your muscular inefficiencies cause undue fatigue.
There must be a reason that most riders seem to slide back on the seat to climb, and slide forward to get top speed. Maybe it has to do with engaging the gluteal muscles more in a climb…I tend to want to anchor my rear to the back of the seat and push off of the seat, but, I’ve proven to myself that I tire more quickly this way. I’m more powerful for a while, though.
It’s an interesting question. I’m just guessing at possible answers.
my cadence was at 88 for the TT on the trainer, 78 on the climb. that is with the virtual cadence fucntion on the powertap, which seems to be pretty acurate.
All of the replies to date seem to have focussed on the leg/torso angle. However, if you climb on your aero bars you will experience exactly the same thing (i.e. more power climbing compared to riding on the flat).
Agreed. That’s why I gave the second reason – low gearing somehow allows me to produce more power. I have climbed that same hill in the bars, and I found it easier to produce more power than I can in the same position on the flats. The difference being gearing.
Big gears induce a higher peak force; we pedal faster to reduce peak force; faster pedaling is less efficient. That is one plausible explanation.
Rick, didn’t you used to say that you spun uphills faster on your tri bike than you would climb, presumably in an upright position, on your rode bike?
I can’t remember exactly what you said, I just remember you had experimented a lot and were faster on the tri bike.
Yes, I did say that. I climb faster (“more powerfully”) on the tri bike, and I’ve been trying to figure out why. My thigh-torso angle when sitting up on both bikes is virtually identical (my armpads are low, but I have long arms and sit pretty straight up on the tri bike when holding the base bars). The only difference is that, on the tri bike, my COG is a farther forward (about 9cm).
After a bit of pondering and riding both bikes, I now think it is a simple matter of specificity. I ride the tri bike 95% of the time (for the past 2 year anyway). When I get on the road bike, I feel awkward and weird and I just can’t get any power going. I am so used to the feel of sitting up more over the bb that, when I’m on the roadie, I feel like I’m falling backwards off the bike.
I am quite sure that equation would turn on its head if I rode the roadie all the time and took the tri bike out once or twice a year.
So, while I used to think there was some inherent advantage to climbing with my COG more forward, I now think it’s just that I’m used to it and I like the feeling of it.
I see a similar thing with my PowerTap. My climbing power seems to be about 10% higher than my TT power. My TT position is not all that aggressive which is perhaps why I don’t see as big a difference as you do.
I think there are two explanations for this phenomenon. They have both been brought up here by others.
When we climb we frequently open up our hip angle which makes us more efficient and powerful.
Second, most of us tend to ride at a cadence higher than our most efficient, most powerful, cadence. When we climb we frequently lower our cadence, which, again, tends to make us more efficient, unless, of course we lower the cadence too much (a cadence of 10 is not more efficient than a cadence of 70 because of the contractile properties of muscle).
Repeat your timetrial in the same position you did the climb and change the gearing to keep the cadence the same (at the same effort or HR) and you should get the same power on your PT.
Your tt position is likely not optimal for producing power. It may be aero, but it is likely too low and/or too long. I bet if you raised your armpads 1-2 cm you would gain power on the tt bike. Hard to say about shortening up reach without seeing you.
I think that the answer to your question is deceptively simple; this isn’t a fair comparison.
Your on-the-bars TT position is optimized for efficiency over a TT length, TT style effort. That isn’t a sub-10 minute, get over the hill effort.
If you were to compare your climbing wattage for, say 30 minutes, I would hazard a guess that it would be much less dissimilar to the wattage you are seeing in your TT position.
IOW, as you increase the duration of the effort, your CP numbers will show less “type of effort” variation. Your CP30/CP60, etc. are likely to be increasingly nearer mirror images whether they are derived from sitting, standing, or etc. type efforts.
Your sample size is very small; one serious out of the saddle blast of 800 watts can skew the average power way up for a 9 minute effort. Increase the duration of the excercise, and see what happens…
Does this have anything to do with the speed you are going? On the climb, the speed and wind resistance are lower and your power goes into the climb. On a flat stretch the speed and wind resistance are much higher; and power goes into fighting the wind. I am not sure if this has an impact on your heartrate for the same power? Don.
